60 Day Satisfaction Guarantee
Where Did the Name Zu Come From
Zu Logo, Marks, & Branding
How Zu is Changing Hi-Fi
Hi-Fi is Dead—Long Live Hi-Fi
Future of Hi-Fi
Zu on Tone
Zu on Burn-in
Zu on the Atomic
Zu on Tests & Measures
Playback—Only as Good as Its Weakest Link...
Zu vs. Convention
Zu's Political Leanings
What Makes a Loudspeaker Good
How are Zu Loudspeakers Different
What is a Loudspeaker Driver
What is a Full Range Driver
Zu's Full Range Driver
Center Cylinder on Zu 10" Driver
Do Zu Loudspeakers Use Crossovers
Zu + Bob Moog on Dynamic Range & Bandwidth
Zu-Griewe Acoustic Technology Overview
Electrical Impedance Impacts Fidelity
Best Tweeter, Best Capacitor, Best Everything
Cables Make a Difference
What is ZuB3™
Copper vs Silver vs Gold
Are Audio Cables Directional
Does Insulation "Dielectric" Make A Difference
Connectors, How Important
Cryo My Cable
Shielded or Unshielded Cable
The Magic Cable Length
Zu has a 60-day satisfaction guarantee, so you can decide for yourself, in your room, your rig, your ears and your sensibilities within playback. We even pay the return shipping and schedule the pickup.
The job of a good salesman of whatever it may be, widget or loudspeaker, is not to convince the customer to MY way of thinking, it's to understand what the customer is looking for, what he or she places value on, how a product might help them realize the sensation or job they are searching for. Zu designs things that are an expression of its people, and while we love our designs, we don't presume to have the same values of music and playback. We really don't "sell" at Zu, we present the thing we make as it is, and hope that it is something that fits the values of the large majority of those that find our stuff attractive.
60-day trial period, and Zu will pay to have the loudspeaker or anything else Zu sales, picked up from your home, at Zu's expense, at the end of the two months if you are not satisfied. Zu is not pushing product, Zu is trying to make friends that will then give its product a try.
If you do decide to return an item prior to 45 days of having it in your home, there will be a 20 percent restocking fee. We don't want our products to "grow" on you, but for you to listen to Zu products performing at their best in order for you to make the most informed decision. Temperature, set up, and burn-in are variables that will have an effect on playback that may be remedied within the 60 days. Zu is creating and making product that express a unique position on tone, hinged around Zu's way of looking at playback, music, and the art of the electromechanical, electrodynamic, and the architecture and form. We hope you like what we do.
Mark O'Brien from Rogue Audio asked Sean this same question once, and he gave him the honest rundown. After the technical spiel he looked down at him—Mark's 6'3" former boxer—and said, "That’s the lamest story I think I’ve ever heard. Do yourself a favor and never tell anyone that story again." Don't get us wrong, Zu digs Mark, the guy races motorcycles, loves Nick Cave, and makes some great audio gear; but if he ever asks you a question you better make sure it's interesting.
So where did the name come from? Like we said, Mark's a big guy and we're workin' on it.... Okay, the stark story, just like most stuff we do here at Zu it was created and engineered from a particular point of view. Kinda boring, but now with a decade behind the brand it's certainly a lot more interesting—the product, the controversy, the history and people, the product. We love our name and brand. Pronounced Zoo, not Z-U.
Zu LogoRepresenting the art of product, performance and design.
All Zu product features this mark.
Craftsmanship | Dedication | True
Zu ManRepresenting human emotion and passion.
Used as a signature, and in select art.
Passion | Music | Hope | Life
Zu SoundWavesRepresenting dynamics, change and technology.
Used in dynamic content in media and symbol of technology.
Dynamic | Central | Expanding
Zu SlogansA Revolution In American Hi-Fi
We're Simply Here for the Music
Zu direct, because the closer you are to Zu the closer you are to the music.
General Electric | Radio Co. of America | Westinghouse | Zu Audio
"It is important to not underestimate the impact of Zu's first model to market, the Druid. In a hi-fi market full of me-too products, where all loudspeakers were configured with multiple drive units and had cabinets designed from the same old computer methodology, the Druid was a radical departure from the norm—an easy to drive full-range loudspeaker, bereft of a crossover (because speaker level crossovers sap power and emotion), visually dominant and that sounded full-blooded by comparison to the anaemic offerings of the main players in the market—it was also dirt cheap for the performance it gave.
To put this into a perhaps more understandable context, the Zu Druid's arrival on the scene is analogous to the arrival of the first ever VW Golf GTi. The GTi hit the streets as an easy to live with 'sports car' that was cheap to afford, outperformed many many so-called exotic sportscars, and basically brought high performance back within reach of the average Joe. In doing so, the GTi defined a template for budget performance that has been replicated by nearly every auto manufacturer around the globe. Once you had test-driven a GTi round the block, you arrived back with a huge grin on your face—life was never the same again. That same grin happened when you first heard Druid and now, every time you hear a Zu loudspeaker, the grin is there. Ultimately it's all about honest-to-goodness performance at real world prices. No wonder many dealers hate Zu—we expose their products to scrutiny and they're found wanting by comparison. Just like the day when some young lad in a Golf GTi blew the doors off a Mustang!" —Simon Matanle / Zu’s Sales & Marketing Director (and VP of Everything)
The hi-fi audio market that developed in the '70s, '80s and '90s is now dead, at least in the United States. The flip-side is music is bigger, stronger and more creative than its ever been. More people are recording cool stuff and the creative musical spirit is laying waste to genre classification, pumping out more original, creative and expressive music than at any time in the history of mankind.
Leading U.S. manufactures and dealers have been focused on short term bottom line results, raising margin, failing to see the necessity of a retail price correction and the fundamental shift to get back to basics—to increase its customer base and not soak the faithful. The icons of the '80s and '90s, those in a position to see most clearly the future of playback chose to cash in. 1990s hi-fi was weird. Those in power did little to expand high fidelity playback. No real leadership, no vision.
The new hi-fi scene is all about sound, tone, lifestyle. Vacuum tubes more popular than at any time since the golden age of playback, and it's no longer tubes vs. solid state, that died with the old guard. It's all about the sound. High efficiency once again back as a primary design goal for more than just a handful of hobbyists. It's the small and new brands that are pushing the refinement envelope and making really cool stuff and selling it for honest prices. Music lovers everywhere... the guard has changed.
There's been so much talk about the future viability of high fidelity playback that it is making all of us at Zu sick. "The unraveling of the high end" "the death of two channel" "the iPod kids of today don't care about fidelity" and on and on it goes. Why all the talk? Certainly history shows that music is a primal force enjoyed by mankind irrespective of environment, nationality or age. People will continue to make and enjoy it, music is ever expanding, ascending, descending and reaching to fill our collective souls. But to disregard the large dynamics shifts in the industry of high fidelity audio, and not just in philosophy but in its trade and lifestyle, is to signup for obsolescence.
What Zu is seeing is a return to the fundamental enjoyment of musics—all music, harmonic, melodic, soft, loud and otherwise—it's simply about the music, now more than ever before. Hi-fi has lost its mantle of keepers of fidelity. It has lost its regard for new sounds, textures, expressions and horizons. By and large its leaderless and burdened with assumptions. It's the end as we know it, hi-fi is being replaced, by systems and devices the new music lover can live with, systems that are capable of recreating sonic events that move them. No, it wasn't hi-fi that saved vinyl it was the DJ and the techno scene. This new generation of music lover is about the DJ, and punk, metal, desert, country, pop, alt, ambient, world, space, goth, jazz, classical, bluegrass, nerd, noise, and the bitchin' and far out. Like most of what is going on in the music scene today, Zu is about sincerity, originality, putting it out there, making it happen.
The original searchers for high fidelity recording and playback embraced sounds in all their forms. The original audiophiles embraced ideals, compromise and new progressions. The original audiophile has much more in common with the new generation and both are a 180 out from where the analytical high-end poser from the '70s, '80s, and '90s lead us. Hi-fi is returning to its roots, returning to the music. Here is a bit from Zu's original communication drafted in 1999 on the eve of our by our bootstraps launch:
'Impressions of new realities struggle and flow—eventual transition. Awareness of surroundings, songs of tranquility and warning—history and intuition instruct that patterns of sound have been a fundamental constant.... Observance of nature, both physical and spiritual, teach us of the endless interplay of vibrational forces. While traveling the line of time we can see many periods of increased awakening and technological advancement but none so powerful and rapid as that of the Scientific Revolution, Enlightenment and the birth of modern physics. The dramatic increase of understanding regarding possibility, vibration and energy coincide with our collective ability to listen and express patterns of life. David Toop in his book Ocean Of Sound paints a powerful image of our modern musical awakenings: "...Starting with Debussy in 1889, is an erosion of categories, a peeling open of systems to make space for stimuli, new ideas, new now, this environment included sounds of the world—previously unheard musics and ambient sounds of all kinds, urban noise and bioacoustics ... unfamiliar tuning system and structuring principles, improvisation and chance."'
In 2005 Zu expanded upon this theme, condensing and adding to these thoughts, turning them into a hard hitting marketing statement—A Revolution In American Hi-Fi. It's the return to musical exploration, tradition and character. it's the return to reason, to ease of use, accessible and fitting for normal homes, it's the return to searching for new sounds and insight through them, A Revolution in American Hi-Fi is the return of sincere craftsmanship and design in the devices that recreate those sonic events. It's simply a return to living music.
Zu isn't trying to capitalize on hi-fi's change, Zu is trying to participate in it, embracing and helping the new sounds and expressions along. Zu is carving out its contribution to the art of playback—in its products, music lifestyle marketing, and sincere attitudes about music, fidelity and corporate integrity.
Zu has been approached many times by hi-fi industry movers and shakers, asking how to reach out to the youth and tap into younger markets. This question reveals just how lost today's hi-fi industry is. Zu isn't 'reaching out' its living it, making it. Zu is actually reaching out to the older generations, to those in hi-fi that can help bring about a revolution in the return, where hi-fi is restored to it's proper place in the home, out from the cave and back to the living room, back to the first or second thing an eighteen year old kid needs in his dorm or apartment. Sure it's traditionally been a guy thing, but not in the new scene, girls are into it, the second and third biggest music lovers at Zu are girls, and that's pretty normal in today's music scene.
The fragments of hi-fi that remain must embrace the techno and everything else that has come along since Elvis, Dylan, and the Beatles. The new scene, where it's about the music, is looking back at their heritage. They know Miles, they know old country and even the great composers. The new scene gets it. Embrace them and learn from them.
Tone is quality in pitch, harmonic composition and time, exhibiting linear dynamic behavior in the infinitely complex intensities of music. Tone is not how something measures but how it sounds. Made popular, though in German, by Herman Helmholtz in his groundbreaking work Sensation of Tone written well over a century ago. The correct usage has survived and flourished in the musicians world, particularly with guitarists which have a very good sense of usage.
Burn-in makes a difference to nearly all things associated with the audio system. This may sound like some kind of grand statement, and what follows is only vague because our collective sonic understanding of the atomic world is weak. The quantum world is almost beyond comprehension, and can be modeled in many, seemingly irreconcilable ways.
Nearly all solidly burned-in audio equipment, including cables, sound better than the same devices when new. Many even feel that loudspeaker cabinets, like musical instruments, need years of play and aging to sound their best—nearly all old Tannoy owners feel this way. Certainly all audio cable or wire impacted transmitting and receiving systems are influenced by burn-in. Why? We're not totally sure here at Zu. There are so many variables and very little conclusive in-depth scientific research that can be correlated. In 2001 Zu began tracking and investigating the effects of signal and power on various cables and loudspeaker systems and has stumbled on a few tricks and process that get us pretty excited. Electric burn-in seems to relate to the stressing of the insulator's electric behavior (Wave Mechanics or Quantum, both seem to get you there in this case), standing waves, or is it electron orbital, or is it electron clouds, or sets and metrics.... Interplay with van der Waals forces, electric standing waves and Pauli exclusion effects too; not only between signal / power and insulator but also the conductor and the conductors electric behavior. Catalyst for electronic change is the propagation of signal and its power component. It looks like little to do with the "conductors changing structure" as a few cable marketing companies have hyped. Even with a few happened on insights of our own, and the work of many others, we are still not prepared to release any new data or findings; we can only rely that we fully believe in the sonic effect we hear. How real, and how much difference is there? Significant in most cases, and so significant that we made some heavy investments in the exploiting of the phenomenon. Just check out our level of commitment to factory burn-in and process for our loudspeaker systems. We found while running extreme soak tests on them that there is potential to not only improve a wire, cable, component, or loudspeaker driver through long hours of play, but to actually improve the component or system beyond what is possible with a traditional burn-in or break-in procedure, or even years or decades of play and aging. So in 2006 we undertook the challenge of applying some of our accidental discoveries, along with all the great stuff from the giants of physics, to production processes and finished products. Sure there were a few accidents, like burning up a rack of power amps, cooked voice coils, and shredded driver cones, but the time, money and setbacks have been completely worth it. The proof of the pudding is in the eating, or in Zu's case, how satisfied the customer is in the listening.
Zu's first big indicator that burn-in was essential to get our stuff sounding it's best.... One of the original pair of Zu Druid loudspeakers was shipped to Don Garber of Fi in New York, he liked them but never loved 'em. A year later Zu had them collected and went about checking them over. The consensus at Zu was that Don should've loved 'em, and that someone at Zu must have screwed something up. Everything checked, just like new, and that was the problem. A year of play with very low power two watt tube amps had done nothing to break them in. It was then Zu realized that most users are not going to lean on them the way Zu does, and after thinking about it for half a second Zu realized that its whole concept of how its speakers were going to be broke-in was not possible for the vast majority. Concert level playback, concert after concert after concert... yeah, Zu had to get a soak and burn-in system up and running quick, the difference between new sound and run-in sound is big.
September 31, 2006 Zu committed to running all loudspeakers though Zu's factory burn-in system. This aging / burn-in treating process system ensures Zu loudspeakers will sound their very best. Result, the user no longer needs to be concerned with burning them in with specified program material or at high playback levels. Just play as you will. They will sound better as time passes, but users really shouldn't sweat it. A new pair of Zu loudspeakers that have been hit with factory burn-in process will reach peak performance within a very short time, less than a week typically in the summer months; two weeks in the winter—wide, cold temperature gradients it seem causes delayed burn-in for Zu loudspeakers.
Zu is excited about the system and process, and since adding it as part of the manufacturing process its 60-day satisfaction guarantee refunds have gone from roughly 6% to 1%, and the comments from customers have gone from, "they sound good, but are a bit restricted sounding, when will they be completely burned in?" To something very close to, "Man, these things rock!" No, I'm not kidding. The difference is night and day, that's how we hear it, and that's what end users are telling from all over the world. Proof was reaffirmed in the first quarter of 2011. In the fourth quarter of 2010 Zu introduced the Omen series, and as a cost cutting measure announced that this line would not be getting factory burn-in. This was a mistake and Zu again saw the rise of its return rate, hitting about 8% this time. Lesson learned, ALL Zu loudspeakers now have factory burn-in.
Humanity's creative prowess and appreciation for music is a clue to human awakening. Is mankind's understanding of the atomic world correct? Don't know, but if we look back in through history you would have to say it's unlikely, we only model as bold as we think. I know that I prefer wave mechanics and talk about the electronic in terms of standing waves—more the Schrodinger view—makes a ton of sense to a guy with a very strong acoustics bend. But it's the craziness that is Quantum that holds a lot of the keys or tricks to audio fidelity and real solutions for the electronic. Since the days of Rutherford, Born, Schrodinger, Heisenberg, and others, really since the general acceptance of the Copenhagen Interpretation of the atom, we have had these models by which a very high degree of observation and prediction can be made. This culmination of understanding, what is held as the new and current view of atomic physics, takes us back to the late 1920'—concepts and mathematics that we are still struggling to wrap our minds around. Despite being at odds and less than unified, Wave and Particle Mechanics, Matrices Math, and Quantum Theory are the language through which non-mechanical burn-in (electric) is to be comprehended. For most of us I would simply say, use your ears—God didn't just glue them on for looks you know. It's the sonic observations of change (observation and application) not the theoretical that have formed and guided audio freaks like you and I in our handling of the burn-in phenomenon.
Sonic arts are measured with your gut, not a slipstick. Complex specifications do little to help the rest of us get tone in playback, and reveals little about how a device will help connect your soul to your music.
Test and measures dramatically accelerate the research and development for the experienced and tone conscience engineer, those that have built a knowledge base of factors. Tests and measures are also necessary for proper quality control. Measures and the whole scientific procedure is a very complex undertaking, and very much worth the effort for the engineer. But how tests and measures might relate to your buying decision I'm not sure and here's way. Basic measures tell little about how the product will sound. Published specs might give some indication on how a loudspeaker might match up with a particular amp, or how a particular cable will fit an application, or that a phono pickup will work mechanically with a particular tonearm and deck. But as for graphs, it is extremely difficult to draw conclusions on sound. Also, the methodologies used by one manufacture or lab or system will vary wildly, making cross comparison essentially meaningless.
In the end it really is about the sound, and Zu fully supports the design ideal that the ear and soul are the final arbiter of sonic pleasure. Nevertheless Zu has and will continue to expand its published methods and measures.
"THE sensation of sound is a thing sui generis, not comparable with any of our other sensations. No one can express the relation between a sound and a color or a smell. Directly or indirectly, all questions connected with this subject must come for decision to the ear, as the organ of hearing; and from it there can be no appeal. But we are not therefore to infer that all acoustical investigations are conducted with the unassisted ear. When once we have discovered the physical phenomena which constitute the foundation of sound, our explorations are in great measure transferred to another field lying within the dominion of the principles of Mechanics. Important laws are in this way arrived at, to which the sensations of the ear cannot but conform." —Lord Rayleigh
Nonsense. In fact, the playback system does not behave as a chain at all. Sure, a chain of events needs to take place to get sound out, but really it's a system and must be approached systematically. "Loudspeaker System" "Playback System" "Sound System" Like any complex system, the playback rig, and its environment, cannot be fully modeled without understanding of its components, relationships, and acoustics. This is not to say that devices sonically evaluated within any given playback system can only be done by those few with profound understanding.
Here a some facts to consider:
It's easy to present situations that cause a desired result. Both in oneself and in those you wish to influence. For the most part it's quite easy to know performance changes relative to primary system attributes. Shades and gradients of primary and secondary attributes are much harder to wrap your ears around but it is usually within the combined secondary attributes that we find the magic we are looking for.
Zu makes cable, so lets take a look at cable evaluation. If observers are really trying hard to hear a difference because they believe the difference will be subtle, this will compound the potential for outside or psychological influence. If the observer has a predisposition to a model or brand being compared there will likely be subconscious events that will shape the outcome. Also, if a demonstrator wants to influence the observer there are several tricks he or she may use to produce the desired results:
The only way to know the performance of a device is to follow some semblance of scientific observation. A double blind test within a large enough sampling of gear and people with the observers keeping their notes to themselves until the completion of the study. But even then, the whole system thing is pretty massive.
A simple cable test could consist of two or more observers and a controller that have at least a basic understanding of musical acoustics and can accurately communicate using musical or scientific terms. The controller must not communicate anything to the observers during the test except the test number. There should be two cables to be observed; three usually increases the level of complexity and duration to unusable limits in terms of information and listener fatigue. The controller must also account for any change in amplitude between the two cables prior to running the test. (Electrical characteristics of a cable influence power transfer between transmitter and receiver.) Observers are not allowed to know which cable is under test or know the device cycle. Then there is the very large topic about recorded material and how it factors in, but a song or two are selected and the set is played twice without change to the system. This is so the observers can listen to the music the first round and then take notes as she or he listens to the set the second time. The controller randomly changes between the two cables, sometimes leaving one cable in for multiple cycles and so on. The evaluation session should not last longer than an hour.
Bottom line, search for your sense of sound and trust yourself, you know what you are looking for. If you don't, you wont find it in the forums.
The child in us wants a shootout, wants a winner and a looser—and we still love the competition and game in it. It's nothing we're hiding, we love bangin' bars, swappin' paint, and roostin' the shit out of buddies on the race track, and don't mind getting roosted either, we love the competition, dirt, street, water or otherwise. But here, in the domain of playback... it's not that kinda Competition is it. But even if it were, we have a difficult time discussing methodologies, tests and measures with leaders such as John Atkinson—attempting to convey where Zu places value relative to the scientific understanding of music reproduction, and the quality assurance systems for consistency—how then could Zu get along with a competitor, neither of us racing on the same corse! But this is a secondary issue. After all it's the ear and the individual's sensation of tone that is the final arbiter of sound quality, not tests and measures. And as all individuals place differing values on that sensation, there can be no absolute sound, and no number 1 plate or owner of fidelity.
Zu's position on playback is not conventional. just today we had a friendly discussion about this, the art of playback and tone, with a playback enthusiast / musician... (okay, getting off track, I'll come back to that some other time.). When an artist or musician is recorded, tracked, mixed and mastered, the whole process is with playback as a new creation in mind, not a reproduction. This process has little to do with the real event, unless of corse you are a recordist that is after those natural soundscapes; the interplay of a forest's ecosystem late at night; the tolling of the prayer bell in some remote mountain Tibetan monastery.... But even then the mind's ear is on the recreation of the capture, as a new event that compels in a new, yet related way. The point is, It's all very unlikely that a best for me, is also the best for you. Playback of music is an art, as is the art of music. Yes, there are musicians that are so technically skilled it's ridiculous, but most of the time it's the sloppy rock and roller or untrained artist that expresses something new and emotionally compelling (Elvis, Beatles, Gram Parsons, John Lydon, The Clash, Nirvana.... What matters is how a product performs within a system to move the invested individual emotionally; and ultimately connecting a familiar, desired and anticipated response.
All the great classic works on the physics of sound and sensation of hearing and pleasure put emotion and our response to tone as transcendent of tests and measures and logic. Musical scales, reasons and relationships are definable, and with understanding we expand our ability to create and explore this sensation. They are means to expand the journey, to increase our ability to overcome exposure and broaden our collective ability to create and grow. Looking at history we see a clear link between the explosion of musical expression and our understanding of the physics and creative application of it. Read: Ohm, Helmholtz, Jeans, Rayleigh, Lamb, Olson.... All place our sensation of tone as transcending understanding—our individual 'ear' as the final arbiter.
Individuals that make up Zu are red blooded Americans (all save Simon, Zu's "VP of Everything" born and raised English and living in Brighton) that think what Washington, Madison, Jefferson, Adams, and the other U.S. founders did was genius. We are not always happy with our leaders, we don't always agree with each other, but we are proud of our system, a system were we can prosper, fail, learn, expand, live, and let live, get involved and change things. We believe in the guiding principles the U.S. was founded on; individual freedom and individual responsibility, equality, and solid education throughout the nation—language, math, science, history, art, music... all topped with a huge scoop of common sense.
The U.S. has done and will continue to do amazing things, so long as freedom, truth, adventure, and individual liberty are the forces guiding it. So what's the bottom line on Zu's political leanings? Simple, it doesn't have one. Zu is a corporation, an entity to enable the creation of cool products, business and hopefully wealth. Zu's only here for the music. If you want to know and talk politics and religion (not regarded as polite in most books) then go for it, our individual views are our own... and Zu, like Elvis, is officially on record as only being here for the entertainment.
Benade, Arthur H., Fundamentals of Musical Acoustics, 2nd ed. (Dover, 1976, 1990)
Boylestad, Robert, and Nashelsky, Louis, Electronic Devices and Circuit Theory, 4th ed. (Simon & Schuster, 1987. Original 1972, 78, 82, 84)
Cheney, Margaret, and Uth, Robert, and Glenn, Jim, tech. ed., Testa—Master Of Lightning, (Barns & Noble, 1999)
Cheney, Margaret, Tesla—Man Out of Time, (Simon & Schuster, 2001)
DeSoto, Clinton B., How Recordings Are Made Series, QST Vol. XXVI No. 10, 1942
Everest, Alton F., The Master Handbook of Acoustics, 3rd ed. (TAB, 1994)
Feynman, Richard P., and Leighton, Robert B., and Sands, Matthew, The Feynman Lectures On Physics Vol. 2, (Addison-Wesley, 1964; © California Institute of Technology)
Halliday, Resnick, Walker, Fundamentals of Physics Extended, 5th ed. (Wiley, 1997)
Helmholtz, Hermann L. F., On The Sensations of Tone, 4th ed. trans. Alexander J. Ellis (Dover, 1954. Original 1885-77)
Jeans, James, Sir, Science & Music, (Dover. Original 1937)
Kinsler, Frey, Coppens, and Sanderds, Fundamentals of Acoustics, 3rd ed. (Wiley, 1982)
Lamb, Horace, Sir, The Dynamical Theory of Sound, 2nd ed. (Dover, 1960. Original 1925)
Olson, Harry F., Music Physics and Engineering (Musical Engineering), 2nd ed. (Dover, 1967. Original 1952 & 1967)
Partridge, Eric, The Concise Usage and Abusage, (Great Britain: 1954)
Randall, Robert H., An Introduction to Acoustics, (Dover 2005. Original 1951, Addison-Wesley Principles of Physics Series)
Rayleigh, J.W.S. Baron, The Theory of Sound, 2nd ed. Vol. 1 & 2, (Dover, 1945. Original 1894)
Seashore, Carl E., Psychology of Music, (Dover, 1967. Original 1938, McCraw-Hill)
Tesla, Nikola, The Complete Patents Of Tesla, Nikola, Edited by Jim Glenn, 1886-1916 (Barns & Noble, 1994)
Williams, Trevor, ed. Biographical Dictionary of Scientists, (HarperCollins, 1994)
NARAS Journal — Volume 8, Number 1 (Spring/Winter 1997/98) The Father Of Invention.
QST—Vol. XXVI No. 10, October 1942, Copyright American Radio Relay League Inc.
(A bit of—us vs. them—done so for perspective. Right on, that others are also making speakers, and very likely most of them are very nice people. Our position then....) For us, a good loudspeakers play all genres of music, with real intensity, is dynamically expressive of tone and texture and is in perfect time—all with convincing tone, putting the music out in a way that hooks you and pulls you in, or rips your guts out—good loudspeaker almost force your attention, and make you want to live life bigger, with greater effect, and boldly. Today we are cursed with a market full of unnatural sounding speakers, most featuring three or more speaker-drivers, complex crossover networks, low efficiency, and all claiming to sound perfect, lifelike, and better than the rest. Empty rhetoric if you ask Zu. Modern hi-fi speakers sound amazingly similar, and nothing close to real. Tweeters that make your ears bleed, woofers smaller than pancakes making all drums sound fake, and the stereo image they cast compares on a visual level to early '80s computer animation. The way the majority of loudspeakers are being done in hi-fi today cannot be the right way.
We think a loudspeaker must have a wide dynamic range, which is the ability to play from very low to very high levels, with a linear, distortion-free dynamic behavior. This is held as the fundamental rule on which all Zu loudspeakers are based. In any loudspeaker there are five fundamental areas that make up its quality or tone: frequency, bandwidth, time, dispersion, and dynamic range. An engineer can, in most cases, borrow (or diminish) dynamic range to fix problems that exist in a loudspeaker's bandwidth, frequency, and time domains, but the opposite is not true, leaving dynamic range as the defining character. Either a speaker has it, or it doesn't. (Not forgetting dispersion, but this is application specific.) When playing music these domains do not behave in a linear way and it's the deficit, or linearity between them that must be the engineers focus if real tonal and dynamic fidelity is to be had.
In addition to dynamic realism, a good hi-fi loudspeaker will also create a uniform, full range wave front, with all notes emanating in the same time, so fidelity can be had throughout a listening area. Tone-textures, density, resolution and spatial qualities are all degraded if this is not realized. Nearly all of today's loudspeakers fail to meet these criterion with linear dynamic behavior.
A full range, direct radiating loudspeaker driver can provide better timing than a multi-driver loudspeaker and, when properly designed and built, can eliminate the distortions introduced by crossovers and filters. Zu hi-fi loudspeakers do not use crossover or filter components on its full range drivers, and believes you will notice the clarity, aliveness and presence—even if you are used to much more expensive brands.
Tests and measures can easily show all five facets of a loudspeaker's performance, however, current practices in measuring loudspeakers—steady-state, odd FFT and data processing, single point mic location—result in little correlative data as to how it will perform under dynamic conditions, like music, and have little relevance to how it might sound in a living room. Technically, bandwidth does fall within amplitude domain but since bandwidth is so important, and can be engineered around amplitude goals, Zu handles it as a primary feature.
In a market where nearly all speakers are the same it would seem either Zu is wrong or everyone else is. There are many additional points that make Zu loudspeakers remarkable, but the following five distinctive traits lay the foundation.
Zu's 10" high efficiency, high power handling driver platform. With high power amplifiers saturating the market, why would anyone looking at loudspeakers consider high efficiency as an essential design feature? In addition to the technical reasons stated in "What makes a loudspeaker good" high efficiency is necessary for low power amplifiers; and the Zu + tube combination, especially single ended triodes, is certainly addictive; as can solid-state. Regardless of amplifier selected, a wide bandwidth driver with high efficiency, combined with wide dynamic range results in very real resolution and contrast. Combine dynamic range with good frequency and time behavior, and get sound that is so effortless and engaging that you find yourself making excuses to spend time listening. Zu loudspeakers give an owner the option to connect just about any amp, from a little 1 watt single-ended triod, through the super high-output transistor amps. Zu's resolution and intimacy allow users to explore amplification at a whole new level. And this brings us to another side of the Zu speaker, that of high power handling. The main percussive feature in today's music is the kick-drum and most hi-fi speakers can't even look at a one, let alone reproduce it. They are either grossly inefficient, can't play transient bass, or can't handle power. Many loudspeakers have power handling, a few have high efficiency, Zu has both. Moderate to high power combined with the high efficiency of Zu results in a dynamic range able to recreate concert level playback, or thunder claps, or car crashes, or jet flybys.... Zu believes in having the ability to do real levels without risk of damage to your gear or ears. (It's high sustained SPL levels plus noise that is the destroyer of gear and hearing.) You won't have to turn up the volume to uncomfortable levels to get convincing bang from a soundtrack or crescendo from Wagner.
No crossover. Zu loudspeakers are designed and built well enough not to need "fixing" with crossover and other electronics parts. Today, nearly all home audio loudspeakers use plastic or metal cones and crossovers. They do this as a cost savings measure, plastic cones are easy to work with, and crossovers allow you to fix and tweak without the expense of heavy time and tooling. We also think plastic and metal cones are used as a gimmicky sales tool; new and different equals better. Loudspeaker drivers today are designed to look good first and produce a salable sound second. In the '50s, budgets and living room spaces were being split between television sets and audio, and it was during this time that acoustic suspension speakers were introduced. Consumers began to gravitate to small speakers that gave the impression of big sound, and today's speaker builders continue in this convention. Real fidelity has all but disappeared in today's living rooms and anyone who has tried to playback rock, big orchestra, even piano recordings on their home speakers at moderate levels knows it's a long way from lifelike. For over fifty years now it has been, out with the big well-made speakers and in with the new smaller and cheaper ones featuring cost mandated imported drivers, engineered to sound impressive but not really delivering realism. Zu on the other hand has continued on the course set out by Western Electric, RCA, and others, using paper based cones, even leaning heavily on the exceptional 1930s RCA research and designs. Not being afraid to design and produce their own speaker-driver has allowed Zu to create a modern device that is capable of playing bass, mids and lower treble with better overall fidelity than the multi-driver designs of today, and without filter parts injecting noise, robbing efficiency, and sucking the soul from the music.
ZuRG™ technology. Zu's driver / box / acoustic impedance matching technology. Zu has designed a speaker-driver / box / room loading technology that reduces the acoustic impedance ratio of loudspeaker cone to room, thereby increasing efficiency and reducing cone motion. This original technology significantly widens the usable bandwidth and reduces distortion. It does not introduce distortions common to horn loaded speakers and is operable through several octaves.
With other speakers and technologies, if bandwidth is widened distortion is increased. Bass-reflex speakers are infamous for this, as are transmission lines, and acoustic suspension designs.
Zu cable inside. Zu does not skimp on the internal cable of its loudspeakers; no zip-cord running about, no cheap imported wire, nothing that will get in the way of performance. Zu manufactures its own cable and places considerable attention to this aspect of design. Zu's own B3 internal cabling, combined with solderless and cold forged termination techniques lower noise and increase resolution, and significantly enhance amplifier/speaker intimacy. Within Zu loudspeakers you will find original Zu-designed and built cable assemblies using nothing but the highest-grade Zu cable product.
Zu builds what it sells. Today's audio companies focus more on product style and packaging than fidelity or lasting quality. It's a, profit first, never mind performance or craftsmanship so long as they sell, business. Zu on the other hand makes audio gear with performance and build quality first; trusting that if it builds the best products, with a duty to community, sales and success will follow. Imagine, products selling themselves.... To maintain its inventiveness and realize its long term goals, Zu chooses to use critical components and sub-assemblies that have been developed by, and are made at Zu. Simply, our products are made by us at Zu; tested, listened to, and packaged at Zu—If it wasn't invented or made by us, we have a serious problem putting our brand on it. Really, how much difference is there between loudspeakers that all sport nearly identical speaker drivers? If a manufacturing company is not continually reinvesting in production and tooling you can bet they will fall behind, maybe lose everything. Just look at the history of Tesla's company or Western Electric.
Oddly, Zu is the exception today, most outside the aerospace / military companies no longer make product themselves, choosing instead to outsource the majority of their product. For every ten loudspeakers sold in the US at least nine are made in China. If you are a Chinese company, you should build it in China, and if your company is in Ogden, Utah you should build your products in Ogden. Sure there is a huge temptation to outsource and to get some of that cheap labor, but not for something you really care about, something you build that will be used nearly everyday of its life!
There are several other features that are original to Zu, but really, what it all comes down to is how the thing sounds to you and in your own living room.
A loudspeaker driver is the part of a loudspeaker that converts electrical energy into acoustic (transducer), generally incomplete without the supporting enclosure and tuning system that together make up what is known as a loudspeaker system, "speaker" for short. The loudspeaker driver is nearly always of the electrodynamic type, consisting of a frame that supports a magnetic circuit, a cone and suspension system and voice coil.
In usage, Harry F. Olson, helped define the term full range driver: as any loudspeaker drive unit capable of quality reproduction of bass through treble (musically defined) with usable dynamic range when matched to the supporting acoustic space such as the speaker cabinet or mounting baffle.
Traditionally, single drive units capable of covering the bandwidth of roughly 60 Hz to 8 kHz have for over six decades been distinguished and marketed as full range. Zu specifically defines its use of the term full range in its marketing efforts, stating that its 10.3" full range driver has an in-room bandwidth capacity of 35 Hz to 12 kHz, roughly eight and a half octaves. Super-tweeter covers the top octave; harmonics on muted trumpet, pan flute, a bit of shimmer on cymbals, and burnish on strings.... For more info and perspective on full range driver terminology and some history please see Wannabe Curation Communication listed under Forum Claptrap.
Zu is responsible for the net parameters of the driver, designed to sound good to us—and hopefully others—with heavy bias on dynamic expression, dynamic resolution, tone and texture, baritone weighted, and work with ZuRG™ loading technology.
Zu260FR 12 ohm, 5010 grams (2001–2003) original design
Zu260FR/G2 12 ohm, 4660 gr (2003–2006) changes to the motor and surround to improve bass
Zu260FR/G3 12 ohm, 4660 gr (2007) changes to cone, assembly, batching / matching process
Zu103FR 16 ohm, 5193 gr (2007–2009) Presence only, Max shove / low Qes motor assembly
Zu260FR/G4/Essence 12 ohm, 4807 gr (2008–) Essence specific, MLS, stiffening/weighting ribs
Zu260FR/G4/Omen 12 ohm, 4791 gr (2010–) used in Omen series. MLS added
Zu260FR/G4/HO 16 ohm, 5338 gr (2010–) Soul Superfly, max shove motor
Zu103/ND/G1–16 16 ohm, 5336 gr (2011–) Dominance and Definition Mk3
Zu103/ND/G1–8 8 ohm /// under development
Zu machines and assembles the final motor work, finishes the driver frames, performs the final cone prep, binds and treats the cone, soak tests and proves the completed driver with a minimum of 300 hours of burn-in, final QC, testing, and tolerance matching. Our driver is made primarily by us and Eminence, with a few parts coming from other suppliers. It has many things finished by Eminence: the voice coil, the charging of the magnet, the riveting of the yoke / magnet / frame assembly, layup of the primary cone, the former assembly. And as stated, the driver is based largely on 1930s technologies and research. Harry Olson had his hands all over this format, the cone geometries, jib factors and suspension, voice coil size.... From what we can find the original cones were made by the Hawley paper company, and this full range platform originated from RCA in Harry circa 1934. To say this is Eminence's or Zu's is delusional. Zu has certainly added it's feature to the platform, modern materials, improvements to bandwidth, power handling, power transfer.... All versions of the Zu 10" platform are unique, with differing applications and Thiele/Small electromechanical parameters. It's funny that in 70–80 years audio hasn't been able to really improve the basic design of a this rock solid 10" full range platform.
Zu full range drivers utilize diamagnetic materials in its motor to influence and shape the inductive dynamics under power of the interaction of static field and field of the coil. Considerations and design features relative to frequency, the eddy currents formed (the shape of the B fields of the coil relative to frequency and wave form) are also designed into our driver. These features are fully operative and designed to continue to be effective even under extreme SPL demands.
A machined phase plug assembly, which is not in motion, directly connect to the frame/motor assembly, with both visible and hidden features allowing for the following benefits:
Network components or bandwidth limiting elements are not used on any of the full range 10" drivers. Cable comes in and runs full bandwidth directly to the voice coil. No inductors, resistors, capacitors, nothing. There is a high-pass network on the super-tweeter. Yes, Zu's full range drivers do exhibit aggressive high frequency attenuation around 12k and up, but this is a function of the intrinsic behavior of the transducer (speaker driver) which cannot be defined as a component within a crossover network.
If a driver is running within its usable bandwidth without any network filtering or resistive influences, its low / high roll off or slope (knee, also referred to it as phase angle—dynamic behavior of the transducer as resistive elements, i.e. mechanical, acoustic and electrical functions of the motor...) should not be referred to as a crossover function.
The definition of a crossover as used in the audio lexicon, short for crossover network, must function as an isolated component and cannot require external reactive elements to complete it. A crossover network must perform the following functions: split a single input signal into at least two output signals, one output limiting bandwidth to the lower frequencies and the second output limiting bandwidth to the upper; having a "crossover" point between the two bands which will (hopefully) sum close to zero attenuation. In a three-way crossover network you would have the addition of a bandpass—one input signal, three output signals; low frequency band, mid band, high frequency band, with each crossing point between then summing to roughly zero.
There is of course an acoustic crossing point between the super-tweeter and full range driver on a Zu loudspeaker, which can certainly be described as an acoustic crossover point, since both sources have a common input signal, but the term crossover used in this way is attributive, not a definition of technology.
Wide dynamic range is realized through correct design of the driver's motor system and the loudspeakers impedance match ratio to the room. In the early days of audio, inefficient loudspeaker drivers were made much more efficient through the use of horns. Horns are acoustic transformers, able to couple a high acoustic impedance like a dynamic driver, to the relatively low impedance of our atmosphere thereby radically improving power transfer. Western Electric and others were getting 50% efficiency with their monumental horn systems designed for the early theaters, and yet hear we are nearly a hundred years latter happy with 2% efficiency in our homes.... But theatrical perfection and horns don't really fit in normal homes, and even if they did there would still be fidelity issues, even in the largest of living rooms. Since horns are bandwidth limiting, only able to cover a few octaves without introducing high levels of distortion, an array of specific horns must be built to adequately cover the musical scale. The most basic is a two horn system, bass/midrange and midrange/treble. Large systems able to cover the entire musical scale were made up of five horns or more. Bandwidth optimization and splitting the music also resulted in timing issues and the introduction of the loudspeaker crossover network. The two technologies did allow for a huge net improvement in fidelity back in the day. So, after roughly eighty years of band-aids and increasing complexity, Zu is continuing the search for real solutions for underlying problems, and is doing so through researching the work of the pioneering giants, application of modern physics, innovation, the use of a highly developed materials pallet; and making combination and assemblies repeatable through high-precision manufacturing.
Others on this similar path include the legendary Bob Moog—engineer with an ear. His comments are all relevant and applicable though in the context of what makes a good loudspeaker for plugging your Moog synthesizer into. His bottom line: "Use spec sheets as a guide, but rely primarily on your ear."
"First, let's talk about acoustic power output. What we want out of a speaker is sound (acoustic power). As converters of electrical power, loudspeakers are generally inefficient. Most of the high-price juice going into a speaker cabinet winds up as heat instead of sound. Good, wide-range speaker systems typically have an efficiency of from 1/2 to 5%. That is, 100 watts of amplifier power may yield 1/2 to 5 acoustic watts of sound power. How loud is one acoustic watt? Well, a premium home music bookshelf speaker will generally burn out before it produces one acoustic watt continuously. A typical full-size professional studio monitor will produce three acoustic watts at rated power. And a supergroup's stadium sound reinforcement rig may produce a total of 100 to 1,000 acoustic watts, wide open. In a typical club environment, a speaker emitting one acoustic watt will produce a sound pressure of around 110 dB SPL onstage. Ten acoustic watts will produce an additional 10dB, which, as the textbooks say, is loud enough to hurt.
"How about frequency response? The lowest F on a bass guitar is 42Hz, the C below that is 32Hz, and low A on an acoustic piano is 27-1/2Hz. Below 60Hz or so, every hertz of response is a significant addition in speaker system size, weight, and price. One person can move a moderately efficient speaker cabinet with a low-frequency cutoff of 45Hz, but it will take two people to handle a 30Hz cabinet of the same moderate efficiency. To my ears, response to 45Hz is necessary for a good "commercial" sound, while a 30 or 32Hz low-frequency cutoff adds a fullness that is sure nice to have. At the high end, you can hear the difference between 12kHz and 15kHz. A 12kHz high-frequency cutoff (and flat response below) gives a smooth, sparkly quality to bright timbres; extending the response to 15kHz adds a touch of brilliance and tinkle that can be significant in recording, or in small clubs.
"Distortion becomes important when more than one pitch is played through the sound system. If you're feeding two or more keyboard instruments through the same speakers, you will have to be concerned about distortion. Unfortunately, speaker distortion characteristics are not given on spec sheets. You'll have to listen for yourself. It's generally audible when loud, low notes are played. To test for distortion, play a loud bass note along with a midrange chord. Speaker distortion will produce a "muddiness" that arises from sum and difference frequencies generated by the distortion component. In general (but not always), high-efficiency speaker systems and large speakers distort less than low efficiency speaker systems and small speakers.
"Without a doubt, a typical good 100-watt guitar amp has the efficiency and stamina to put out a few acoustic watts. However, its frequency response and distortion characteristics are optimized for guitar: no significant response below 100Hz, a broad spectral "hole" around 500Hz, and sharply rising response above 1kHz, with some "warm" (low order) distortion. Guitar amps, therefore, are generally not suited for synthesizer sound reproduction. Similarly, most PA. systems are designed to make the human voice sound good. The P.A. frequency response (determined largely by the speakers) generally has a broad peak in the "presence" region of the spectrum (2–3kHz) and decidedly weak bass. Professional studio monitors, on the other hand, have more-than-adequate frequency response distortion characteristics, but often lack the stamina to produce loud, sustained, steady tones without over-heating. This is doubly true for some music speaker systems.
"Keyboard amplifiers come closest to meeting our power, frequency response, and distortion requirements. High-frequency response is sometimes a problem. Many keyboard amplifier-speaker systems are designed primarily for tone-wheel organs, electric pianos, and similar instruments with little harmonic content. Such systems rarely have adequate high-frequency response for synthesizers. However a keyboard amplifier-speaker system with good speaker response to 12kHz or so is likely to meet all of our requirements for synthesizer sound production. If the speaker system itself is efficient, a 50– to 100–watt power amplifier will produce 2–5 acoustic watts, which is plenty for rehearsal or club work, while a 200- to 400-watt power amplifier will produce upwards of 20–25 acoustic watts, which is adequate for 95% of indoor gigs. When selecting an amplifier-speaker system for your synthesizer, it is a good idea to pick a few speaker systems that are efficient (that is, they sound just plain loud when fed with the output of a modest power amplifier) and then select the speaker from that group that sounds the smoothest and fattest. Use spec sheets as a guide, but rely primarily on your ear." —Bob Moog
This technology is used in the majority of Zu's loudspeakers. Its concepts can be used in any loudspeaker where there are internal velocity changes. The technology concept was introduced in Zu's very first loudspeaker, Druid. Zu-Griewe is a multi-octave impedance modifying acoustic model that can be applied to any acoustic system with alternating velocities; electro-acoustic, electromechanical, internal combustion engines, and so on. It is developed exclusively by the late Ron Griewe and Sean Casey. The original concept is Ron Griewe's, a motorcycle champion that had a nice bit of engineering insight as he sat inching through Los Angeles traffic one afternoon. (More about Ron Griewe below.)
Let's outline a few basic principles expressed in the technology and contrast them with bass reflex (ported) designs, as well as transmission lines, pipes and horns. A bass reflex loudspeaker uses a simple Helmoltz resonator to augment lower frequencies via the air "spring" in the cabinet and the "mass" in the port, tuned to add amplitude response, and control cone motion. A Helmoltz resonator consists of a rigid-walled cavity (the volume) with a neck ("port") with an area and length. The fluid (air) moves as a unit within the port tube to provide the mass element and the acoustic pressure within the loudspeaker box provides the stiffness or spring element; the resistive element is provided by the opening that radiates the simple source sound. All Helmoltz resonators contain these basic elements, and all create sinusoidal waveforms but cannot recreate the complex and dynamic waveforms typical of music.
Zu-Griewe tech is expressed, on a fundamental level, like that of a waveguide with expanding acoustic cross section and terminated and driven at one end. Propagation within the Zu loudspeaker is mostly planer and standing waves are not as stimulated. Development of acoustic models accounting for driver introduced dynamic variables within horns, pipes, and transmission lines revealed areas of non-planer propagation. This turbulence (noise) is wavelength relational and proportional to amplitude. Zu-Griewe can reduce many of these problems.
Applied to loudspeakers, this new technology reduced noise in varying degrees over the majority of the audible bandwidth. These new ideas in acoustic impedance transform function, and the designs they realize are proprietary. The basic idea however is acoustic impedance matching of the high Z of the cone to the low acoustic Z of the room; and the reduction of non-planer propagation in more than just a single octave. There are other benefits as well but our not being discussed at this time.
Original concept as applied to exhaust systems for internal combustion reciprocating engines, is the brain child of the late great Ron "Ogre" Griewe—two wheels and a fist full of throttle. Sean had the pleasure of working and riding with Ron back in the nineties at ATK motorcycles.
Ron was a well-known and well-respected character and professional in the motorcycle world. Known in his younger days for desert racing, always running a bit too close to the edge, but always with a grin and a cigar. Later, Ron made a significant contribution to bikers, street and dirt, in his writings, projects, and leadership at Cycle World magazine. While there he rose to Editor-In-Chief, a position he held for 16 years. But the Ron Sean knew was really an inventor and engineer, a guy that didn't get his knowledge from a can. For him, leaving Cycle World—a bikers dream job, getting payed to ride all kinds of bikes all over the globe—to drag ATK America out of custom one-off dirtbikes shop and into a real production based American made dirtbike factory, made perfect sense. Yeah, it was a while back that Ron and Sean used to ride together, and only a season long, but Sean will never forget the time spent riding and working with him. Ron turned seventy the month before Sean returned to audio; Ron was one fast mother, forget about age. Seriously fast, technical single track or super fast fire road.
Riding the desserts of Southern California? Hit the Husky Monument.
Many loudspeaker designers, reviewers, hobbyist, and consumers, fail to recognize some basic points about how a loudspeaker should be measured and what effects the amplifier can have on tests and measures as well as the musical performance, timbre, bandwidth, presence and so on. This FAQ addresses the most basic electrical relations between amplifier and loudspeaker. The Article does not attempt to detail the more complex dynamic behavior of the loudspeaker system, thermal changes at the transducers motor, loudspeaker cable influences, environmental conditions, nor how an audio power amplifier's design will react to these dynamic impedance variables.
2.8 volts equal 1 watt, right? Only for true 8 ohm loudspeakers.
Loudspeakers are generally reactive AC devises. Power factors and impedance differentials between amplifier and loudspeaker must be considered. Solving for power, watts not voltage, is essential for understanding relationships. Power in watts is current times voltage. Phase angles can be ignored in basic loudspeaker testing but does factor in more complex dynamic behavior modeling. Without the correct understanding of basic power transfer, a complete detailing of the system and device under test, measures and data cannot be accurately correlated into observed fidelity. It should also be pointed out that without a basic understanding of test system, device and procedure, marketing can easily manipulate the tests, data, and you.
The amplifier is a major factor in how a loudspeaker system performances, both technically and sonically. If testing the efficiency of a driver in an infinite baffle, correctly mapping the impedance across its bandwidth, then at least distilling the string of points into a nominal number is essential. You cannot simply pump in 2.83 volts and call it. Data acquired this way has little correlative meaning. Once impedance is known, power and system efficiency can then be tested and the results can be useful.
Application: basic, using a nominal impedance reference. Zu Essence loudspeakers measure 12 ohms nominal. Remember, the speaker driver's measures and performance are in large part determined by the acoustic impedance system (box, horn, baffle...) they are mated with. A basic measure of system efficiency we first solve for current, then voltage, all measures being at the loudspeaker's input.
First solve for amperes; square-root of wattage over resistance (ignoring phase) which equals 0.289 amps. Then take amps times resistance to solve for voltage and we arrive at 3.47 volts input. So a 12 ohm load (Zu Druid, Zu Tone, Zu Omen, Zu Essence) requires 3.47 volts at input to reach 1 watt. An input of 2.83 volts into a 12 ohm load yields 0.67 watts. Nearly all modern tests and measures on loudspeakers simply input 2.83 volts (assumption of an 8 ohm standard) which has almost no lay correlation to actual transduction efficiency and power. If all loudspeakers had a nominal impedance of 8 ohms then a 2.83 volt input would be fine and does in fact result in a nominal 1 watt of input power. With 4 ohm nominal loudspeakers we get; 2.83 volts input which equals 2 watts at input. Again, this example is basic but gives a real idea of how much power is being soaked and how much work is being done. Knowing power into the system, and accurately measuring power out of a system you can then know efficiency. Voltage sensitivity is not efficiency, it is a subset of efficiency. Voltage sensitivity is a useful tool in specific applications and conditions.
Understanding power transfer dynamics will hint to why power amplifiers have such a huge impact on the playback systems timbre, dynamic range, bass response, presence, treble, how loud it sounds, and so on. Remember, the reactivity of a dynamic driver is dramatically effected by the loading model (box, horn, baffle...) and the necessity for measuring the device as a complete loudspeaker. This also reveals how the exaggerated "sensitivity" measures are being generated by the majority of brands. Now that we understand the basic relations between impedances voltage and current we can approach how a given power amplifier might behave and influence the tone, power, and presence of playback.
The best—it doesn't get any better. But better for what application, and better in what ways? All tweeters, all capacitors, all components sound different. Fitting a part within a design is a systematic choice, one might be good for one system or circuit and not for another, and to what end is most relevant. After all, your priorities within playback my not be ours. Loudspeaker systems are just that—systems. It's like saying one capacitor is definitively better, the kind of thing we all see frequently in hi-fi audio discussions. Tweeters, like caps, like wire, like everything, have application within a system and true of all parts and subassemblies. There are no absolute "bests". There are however plenty of biggests, most expensivests, heaviests, loudests....
In hi-fi we take our sound so seriously that we usually cripple it. Hi-Fi freaks like you and me needs to follow the lead of the musicians—there is no best guitar, no best sound or melody or rhythm.... Our musician buddy Dan Weldon comes in the shop from time to time, usually when he needs a tone fix, sometimes to take us to lunch. He'll have a box of a bunch of some thing, and the guitar he's currently lifting deeper tone from. Conversation usually goes like this, "I'm looking for more (insert some aspect of tone he is huntin' for, always specific to the guitar and what he is going to use it for) and I've tried a hundred combinations of these widgets and found the perfect combination. The tone I'm getting is killer, check it out." He plays some stuff through the whatever the system of tone is, looks up with a big huge smile, "Pretty sick isn't it. Best tone yet..." then he goes on for at least five minutes, usually fifteen, qualifying what he's going to do with that sound he's found, how he will use it, and when, at what level, where.... Bests are contextual.
Yes, audio cables make a difference, but they should be the last on your list speaking of your system as a whole. Save yourself a ton of time, money and frustration and know what it is in playback, and the sound, you really want to reach. Get the right loudspeakers for your sense of music and sound, find the happy amp that feeds 'em; then get busy on your analog and digital source needs. Fill your room with a bunch of albums and books. And once you have a hi-fi rig you like, start messing with cable. And careful not to use cables as tone controls to fix a loudspeaker or setup issue—it's a trap that will have you spending more money on accessories than on music. If your system has a timbre problem look at your room, amp, speaks…. Yes, interconnects and loudspeaker cables can make a large contribution, as can power cable, though not as often. Each type should be looked at individually. RCA-type interconnects patch together gear with no power factor; here impedance makes very little difference, at line-level it's all about preserving the inserted signal without introducing reactive elements—parallel capacitance (Cp) being prime—that cause time and frequency problems. It's also about protecting the small signal from environmental influences, RF in all its forms, and to a much lesser degree, acoustic. Loudspeaker cables transmit both power and intelligence and are tackled very differently, with impedance playing a much larger role. AC power cables.... well that's a bit tricky. It depends on so many factors that it's impossible to predict if a hi-fi power cable will even make a difference. The power grid in your area, the transformer feeding your house, the grounding of your home's grid, the noise on your lines, the ground relations of your gear; and on top of that you have the power supply of each component in your playback, and the chassis that protect the power supply, circuits, and mechanisms. The perfect power supply would not benefit from a super duper power cable. But, since perfection isn't attainable, and there are audible changes from mains cable swapping, you get the current power cable proliferation that is hi-fi today. Power cables for Zu is about containing the radiated fields and this takes a whole lot of conductor; a simple foil doesn't cut it. Zu also believes in keeping the ground circuits' impedance as low as possible. All this is a very brief overview focused on the fundamental reasons for fidelity preservation and electrodynamics. Chemistry and other branches of physics are also used by Zu to research, develop and finally market a good sounding cable, but way too much has been made of "conductor purity" to justify the stupidly high prices charged for cables.
ZuB3™ technology is a cable design with specific electric and magnetic field relational specifications. The ZuB3™ specification does not include materials, or chemistry, nor treatment processes. This cable topology was invented by Sean Casey in 2001 and allows signal and power to be transmitted with increased immunity from RF while lowering reactance compared to cables of similar conductance. ZuB3 archetype does not resemble any known geometry. ZuB3 field relations, or physical composition detail are held by Zu as a Trade Secret. ZuB3 is not a straight or twisted pair, star-quad, Gore-quad, Litz, braid, interleave, full or sectional coax, ribbon, sectional ribbon, radial, concentric or any other known cable format. Relative to the desired characteristics and actual electrical measures, ZuB3 reduces overall cable diameter. Manufacture of ZuB3 cable required the engineering and fabrication of new cabling machinery as the ZuB3 format could not be made on existing cabling equipment. ZuB3 cables are manufactured solely by Zu in Ogden, Utah, USA.
Yes, conductor makes a difference but it is a secondary concern. The electrodynamics are the driving elements for cable design, and the materials pallet simply serves that system. Manufactures selling bazillian-nines purity whatever are doing so because they don't have much else to sell you, and they need a differentiator for you to "buy" what they are selling. Lots of bullshit in the cable business, buyer beware for sure. And how about "Treatments", possibly, but here again, chemistry must serve the electrodynamics of the E&M model and application. Customers should buy cables based on performs within their own system, and how much it costs. Forget the hype. And make sure the cable seller has at least a 30 day window to return it for full refund. If they don't you are a fool for buying it. Listen, call it as you hear it, what is right for you might not be the thing for another. There is no perfect sound, there is no perfect cable.
Yes, there does seem to be a directional influences on the fidelity of transmission. This includes single-ended transmission as well as balanced. All conductors and transmission formats Zu has experimented with, from metals to rocks, exhibit directionality and signal fidelity changes. There are influences of the conductor structure and there are influences of the insulators; and it means that nearly all wires or cables will sound better in one direction than another. In some, direction can be reversed, others can't. Some are the result of design and implementation, like grounding shield at only the load end, others are the net result of signal propagation. Please read the FAQ "Burn-in" as well, much of what is discussed there relates to cable directionality.
Insulation makes a difference, and it's a rather big secondary influence. All types of dielectric materials interact and "sound" differently. Silk, cotton, wax, PE, cross-linked PE, Teflons, PO, PU, PVC, Nomax, Kevlar, and on and on and on and on, all sounding different. Even color makes a difference to the sound as Stewart Ono in Hawaii taught us back before Zu was even born. It's impossible to say what is best as application, influence and target performance very. The reason many love the sound a wire insulated in silk soaked in pure carnauba might not be because of the silk.
Several years back a few cable "manufacturing" companies were marketing "no dielectric" for their cables, this is totally false marketing. There is always a dielectric, there is no lightning without the lightning bolt. Maybe they're talking about pure music, were angeles insert the stuff directly into your soul. Sorry for "letting our kettle boil over" as Simon from England would say, but there is so much nonsense in the cable world, and it's hurting the industry that we love. Sure, the guy behind such marketing is likely interesting at a party (if he or she attends such things) but buying their product? Don't do it.
Yes, you need to hook stuff up, and yes, connectors can influence fidelity in significant ways relative to the influence cable has on a system. And as important as the connector system is the way in which a connector terminates to the wire or cable. Zu is an anti-solder crew and uses cold forging (high pressure crimp in the correct sorta way) anytime it possibly can. Very few of Zu's wire and cable products use solder, even loudspeaker cable harnesses feature cold forged to pure copper binding posts, all connections save the voice coil leads are high pressure crimp. So for Zu's loudspeaker cables, if you have the option and the space on the back of your amp, Zu recommend you to go with the Zu pure copper cold forged spade lugs.
Very little original research has been carried out relative to diamagnetic materials and temperature. Most of it is specific to ferrous metals, working strength, structure, and so on. The research that has taken place in the super low temp work relative to diamagnetic metals and E&M behavior at these temps is nearly exclusively for super conductive work—coopers pairs, tunneling, zero resistance—not so much hi-fi. Some hi-fi guys love chillin' their cables, some even their drives, cartridges, CDs, and LPs. We have done a bit of testing, using a very long rates of change and the results so far have not been conclusive. Except on magnetics, like hard disk drives, speaker drivers and phonograph pickups—not favorable.
Make a cable that is as immune to outside RF while minimizing the shielding fix's effect on the signal. It's a balancing act, like most things. Likely Tesla could have built a listening room or home that was free from external RF, and gear that did not radiate RF, and a power distribution system that was free of degrading RF effects, but I don't think he's going to come back and make our collective hi-fi power dreams come true. It's not a case of yes or no, it's balancing the thing and both have their place.
"The absolute best speaker cable length is the length that will connect your amp to your speaker." —Ray Kimber. We love this quote; you want what you need. Setup, placement and function are way more important and influential to fidelity. For most homes or pro studios, length should not be that big of an issue. Even so, some cable marketing companies, in an attempt to reduce the number of units they need to stock are making the claim that a specific length sounds better. It's usually longer than typical and certainly increases their bottom line. Generally shorter is better, but nearly all lengths used in home audio are short. So don't sweat it, get what works with a bit extra, particularly on loudspeaker cables. Having room to mess with loudspeaker placement is huge, generally much bigger than the effect the cables will have on performance.
There are many names for the record player; phonautograph, phonograph, graphophone, gramophone, record player, turntable, deck. The first four are the original names for original devices, all basically the same with subtle differences. In France and the USA the playback machine was and continues to be called a phonograph. In the UK the same modern record playing device has been known as a gramophone. Since about 1910, the device music lovers have enjoyed is properly known as a gramophone. But really, for roughly a hundred years, phonograph or gramophone are essentially the same device and can be used interchangeably.
Edison envisioned and created a recording and playback device that was all one machine. This was coined the phonograph, and it was able to record as well as playback. Alixander Graham Bell took up the business shortly after and his record / play machine, an "improved" Edison machine, was business specific, thus named graphophone. Gramophone was introduced by Berliner in the 1880's as a playback only device, designed for entertainment.
1856, the original sound recording machine is attributed to Edouard Leon Scott de Martinville—Scot father, French mother. It used a cylinder with lateral impressions and was named the phonautograph. Apparently the guy sucked at marketing because Edison had to rediscover the principles when developing a better than Bell's telephone roughly twenty years later.
1877 Edison refines/invents sound reproduction and names the device, or borrows the name from a stenography system, phonograph.
1877, Frenchman Charles Cros, is published describing a method of recording sound; no model was made, not even proof of concept.
1877, Edison files for patent on a grooved disc phonograph (patent No. 200,521).
1878, Alexander Graham Bell enters the phonograph market with his graphophone under the name Volta. Within a few decades, lots of deals and buy outs with Edison, and Columbia rises from the ashes to become the leading entertainment disc producer. By 1900, entertainment is the focus and business and dictation are ignored.
1887, German-American Emile Berliner introduced a disc play-only device which was named the gramophone.
1901, Victor is formed by Eldridge R. Johnson to market Berliner's gramophone. Johnson aggressively expands the disc catalog and creates market share. Also launches a very effective ad campaign featuring the famous "His Master's Voice" trademark.
1906, Victor unveils the hornless Victrola gramophone. Victor, Edison, and Columbia establish records as a mass market. 1929, radio takes off, records sells plummet. RCA acquires Victor. And by the end of the year Edison bows out of the entertainment biz.
Alexander Graham Bell entered the race for phonograph market shortly after Edison's invention of the recording / playback machine named the phonograph. Upon receiving the Volta award from France, and the prize money, Bell and skilled buddy Tainter established the Volta Associates company and set about with both the photophone (yeah, really) and improving on Edison's phonograph. There aim was on the business and legal field and named their product the graphophone. They did improve things but after years of battling Edison they sold the company, which was eventually purchased and controlled by Edison. Bell and Tainter did some pretty wild stuff, using compressed air as a medium, development and refinement of wax for medium, fluid cutting jets for recording. For sure Bell was an outside the box thinker that contributed a great deal to building the recording and playback industries.