What is nanotech to Zu and what do you mean by nano-sanctification?

Zu’s full-range nanotech loudspeaker drivers use pulpwood as a core material along with adhesives and nanometer engineered structural materials to create a very high performance driver membrane.

Why paper as a core? Because wood fibers have an excellent blend of strength, weight and damping for use as a dynamic speaker’s cone, the material is easy to work with and these fibers provide much greater service life compared to plastics, glass fibers and thin metal alloys. The wave dynamics in cones of loudspeakers that are being played loudly are intense and will rapidly break down the vast majority of fibers and plastics. With advances in nanometer engineered structural materials, it’s now possible to improve the wood fiber’s strength without hindering damping or performance over time.

Zu’s “nano sanctified” drivers feature a nano materials pallet developed to compliment and improve the wave dynamics of the paper cone:

  • increased stiffness and shear
  • increased propagation velocity
  • better control of modes and damping behavior

While damping is improved, this improvement is not due to the properties of the materials. Rather, it is due to the reduced weight of the membrane compared to what was required without the use of nano material fortification. Zu’s nanotech cones are lighter than the previous generation. Better power transfer of waves-on-cone to waves-in-air results in reduced damping needs, as more energy is transferred from one medium (the cone) to another (sound in air).

Better strength and lighter weight gives you better dynamics and greater bandwidth, with less modal noise. Clearer, more extended, more dynamic, and natural -- simply better sounding sound.

Nanometer material pallet on first generation Zu nano doped drivers (ZuND/G1, sans engineering detail): ceramic spheres, fumed silica, cristobalite nanofibers. Application: Aerosol within a custom formulated epoxy matrix.

The above is an intended as an overview. The following dialogue is in response to customer inquiry on nano sanctification:

We didn't intend to to be vague but we think it's appropriate as the nano-level world behaves differently than the normal structural world. What's happening down there is rarely visible. Maybe this will all make more sense after additional explanation, so here goes:

The cone makeup is actually lighter by several grams compared to it’s predecessor, as we are reducing the need for other binders and damping compounds. We use epoxy so we can handle the cones safely and so that the nano infused matrix lays atop the fiber structure rather than penetrating it. The nanometer particles are so small that the bond with the material is via van der Waals force -- primarily depending on size, form, and materials.

Most of the time, nano structures are added to epoxies or vinyl-esters to help further strengthen the matrix of synthetic and organic high-performance composites -- such as graphite/carbon, Kevlar, glass, wood and other fibrous materials generally used in heavily engineered, close-mold, resin-infused products. Water is often used as a carrier on surface applications. However, in our case, the water swells the paper core considerably, and the particles are attracted/driven deep into the structure.

There are other problems with waterborne solutions relative to our application -- the natural fibers do not seal and there is lack of definition on the skin/core. We want more of a skin on the cone structure so the paper can continue to act as a good damping force. Only a portion of the energy is transferred to air and the loudspeaker’s surround, spider, frame, and cabinet cannot damp or transfer much wave energy.

Another reason for using epoxy as a carrier is that it makes it safe to spray. While there are other ways to apply it, the sprayable mixture works well for our application, tools, and level of sophistication.

For UV protection -- epoxy degrades rapidly from UV exposure -- we use UV absorbing compounds within the mix that rise to the surface of the skin, protecting the epoxy from the sun.

The matrix is so thin that it’s extremely difficult to see the difference between the old cone and the nano imbued cone, or nano sanctified cone. We like "sanctified". It's not so techy and we think it sounds cool, but that’s just us being fun

In the right light, the nano sanctified cone reflects/refracts light differently and has an odd distant shimmer to it. It's a bit like looking at the nearly starless, cloudy parts of the Milky Way on a dark night, in the middle of nowhere.

Zu’s “nano sanctification” ratios, epoxy compound, and UV protectants are not released.

Posted on February 4, 2014 and filed under Loudspeaker, Show All, Technical.

Does Zu Have An Upgrade Program?


So you've been listening to your Zu loudspeakers. You can't believe how awesome they sound. Now you want to get into a speaker that offers more than what you currently have.

Luckily, Zu offers an upgrade program to accommodate your improving system.  If you have an Omen Dirty Weekend, we offer a 100% trade-in value up to a year and 50% thereafter. All other speakers follow the schedule below:

  • 45-60 Days - 100%
  • 2-3 Months - 90%
  • 3-4 Months - 80%
  • 4-5 Months - 70%
  • 5-6 Months - 60%
  • 6 Months - ∞ - 50%

Caveat: Your speakers have to have been purchased through Zu directly.

Posted on January 8, 2014 and filed under Commerce, Show All.

Where did the name Zu come from?

Mark O’Brien from Rogue Audio asked Sean this same question once. After the technical spiel, Mark looked down at Sean (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, We dig Mark. The man races motorcycles, loves Nick Cave, and makes some great audio gear- but be sure your dialog with Mark is interesting.

So where did the name come from? 

Just like most stuff we do here at Zu, our name was created and engineered from a practical point of view. We wanted the brand to be unique with the possibility of logo and name being synonymous, internationally easy, timeless. Kinda boring. But now, with more than a decade behind the brand, it’s certainly a lot more interesting—the people, the product, and the controversy.

We love our name and brand. Pronounced Zoo, not -Z-U-.

Posted on August 18, 2013 and filed under Company, Show All.

Is your return policy really 60 days?

60 days full money-back return privilege.

We want happy customers and letting you live with the product for more than a few days is the best way to know if you are going to be happy or not. All we ask is that you give the product proper consideration and talk with us regarding setup, tuning and integration into your playback system and home.

If after 45 days you decide the product is not what you had hoped it would be, and you paid the shipping to get it, we will pay return shipping and arrange to have the items picked up! If we paid for the product to be delivered to you return shipping is your responsibility.

If you send the product back before the 45 day mark without first talking with us—we expect you to tap into our knowledge, experience and willingness to help—you will be subject shipping charges and a 20% handling and restocking fee.

If more than 60 days are needed, say you're also evaluating the competition or another component that has not yet made it to you, simply call or email us at anytime within the first 60 days for an extension of the satisfaction guarantee. Provided that your request is reasonable, we can extend the term to 90 days or even longer—we want you happy.

This guarantee assumes the product has not been abused. Guarantee does not cover loss, damage, shipping charges not agreed to or other shipping costs.

Products purchased directly from Zu Audio qualify for this program, as do purchases through our eBay channel, Zu_Promos unless otherwise specifically outlined. Zu products purchased second-hand and through channels outside Zu Audio do not qualify.

Custom orders, unless otherwise agreed to, are excluded from our 100% money-back guarantee. If you have commissioned a custom color or an unusual cable termination or format you may only receive a portion of the original amount back in refund, typically 80%.

Posted on August 18, 2013 and filed under Commerce, Show All.

What is the warranty on Zu products?

Zu products are designed and manufactured to the highest quality. 

However, if something does go wrong under normal home use, Zu will fix or replace the product free of charge. If you come across any problems with drivers, cables, parts, cabinet, etc.- we will fix or replace the product. 


When a product or part is exchanged, the replacement becomes your property and the suspect or damaged part becomes Zu’s property. Parts provided by Zu must be used in products for which the warranty service is claimed.

Warranty specifics for different products

Cable: Exchange for new product (or at least functional equivalent to the original product), or repair.

All standard Zu cables have a limited lifetime warranty with the exception of the Mobius headphone cables, which have a two-year limited warranty. Cable warranty does not cover misuse or broken connectors damaged from misalignment or over tightening. Limited lifetime warranty is available to the original purchaser only.

Loudspeakers: Replacement of product or parts including user-serviceable parts, or repair.

Zu loudspeakers have a five-year limited warranty from date of purchase by the original owner. 
While every effort is made to ensure a perfect finish that will last a lifetime, Zu loudspeakers do come with a finish warranty that covers color fade, finish checking, and oxidizing. This warranty does not cover damage from impact and abrasion or seam/core construction visibilities in extreme temperatures and high humidity environments.

Loudspeaker warranty and service can usually be performed by the user, also known as DIY Service. In DIY Service cases, Zu will provide full technical support. This provides faster repair of the product, minimizes handling costs and hassles, and reduces damage potential to both Zu (and you).

Phonograph cartridges: Exchange for new product (or at least functional equivalent to the original product), or repair.

Zu phonograph cartridges have a limited two-year materials and workmanship warranty. This warranty does not cover misuse or accident. It does not cover premature stylus wear from playing dirty records. It also does not cover broken coil leads, which is the result of using a brush with nap that pushes into the housing and damages the coil or coil leads. 

What voids a warranty?

Warranty does not apply to damage caused by operating the product outside the intended use, accident, another product, misuse, abuse, flood, fire, earthquake or any other external causes. Warranty does not cover damage caused by modification or service performed by anyone other than a Zu representative. Cosmetic damage is also excluded from warranty, as is all product that has any part of the Zu serial number removed.

Zu products are designed to be used in temperature and humidity controlled environments, namely your home or office unless otherwise stated. Storage of Zu Audio products, particularly loudspeakers, in uncontrolled environment may cause damage to the product and will void the warranty.

D.O.A. Products

In the highly unlikely event that a Zu product arrives to you D.O.A. (Dead On Arrival), call us and discuss the situation with a Zu tech- we will ship another of the same product at our expense and arrange for the D.O.A. product to be collected. If after inspection, however, we find that you have misrepresented a returned product’s condition, and that it was improperly handled or used, Zu will charge you for all damaged parts, labor, shipping, and handling of the product.

What you can expect if warranty service is needed

How to get started

If warranty becomes necessary, you must call or email for a Return Material Authorization (R.M.A.) number, or to arrange for user serviceable parts. This provides us the opportunity to assist in diagnosing the problem and helps us schedule a rapid turnaround in the event that parts, service, or repair is needed. Upon factory inspection of parts or product, warranty eligibility will be determined.


While service options, parts availability, and response times will vary, we do our best to keep you happy. We strive for same-day turnaround on cable problems and one-to-three-day turnarounds on phonograph and loudspeaker problems. 


Depending on the situation, you may be responsible for shipping and other charges. International customers should know that Zu will comply with all applicable export / import laws and regulations, and that you may be responsible for custom duties, taxes, broker fees, freight, and other charges.


When shipment of product or part is required, repackage the complete product or part in its original packaging. If you have any questions about packaging, please call or email. Product damage caused by incorrect repackaging is not eligible for refund or warranty and the freight company may also reject your insurance claim. Until we have the product back in the shop and sign off that it is eligible, the product is still your property. Therefore, we recommend that you insure or declare the full value of the product when shipping. We also recommend that you only ship with a freight company that has a good reputation and offers tracking and insurance for the full value of the product.

Within the package you need to also include your contact information.

Please send to: 
3350 S. 1500 W.
OGDEN, UT  84401


Posted on August 18, 2013 and filed under Commerce, Show All.

What do I need to do to return something?

Please call or email us for a return material authorization number. This provides opportunity to assist you and helps us to schedule for rapid turnaround of refund or service. Once an R.M.A. is obtained you must return the product to Zu within 14 days of the issuance of the number.

Return the complete product in its original packaging. If you have any questions about packaging please call or email us for assistance. Product damage caused from incorrect repackaging is not eligible for refund and the freight company may reject your insurance claim. Until we have the product back in the shop and sign off that it is eligible for refund, the product is still your property and responsibility.

We recommend you insure or declare the full value when shipping. We also recommend that you ship with a freight company that has a good reputation and offers tracking and insurance for the full amount.

Please include your contact information and reason for refund within the package. We appreciate any criticism of the product, company and service.

Address any and all packages to:

3350 S. 1500 W.
OGDEN, UT  84401

Posted on August 18, 2013 and filed under Commerce, Show All.

What are your business hours?

Real, live, knowledgeable, human sales and technical assistance is available Monday through Friday from 9:00 a.m. to 5 p.m. Mountain Standard Time.

You read that right. Real humans. Real humans with lots of hi-fi experience that also have customer service training, want to talk to you, and desire to make you happy.


Posted on August 18, 2013 and filed under Company, Commerce, Show All.

Is the customer always right?

Always. Zu has a 60-day satisfaction guarantee so you can decide for yourself if Zu is right for you. We even pay the return shipping and schedule the pickup. The customer comes first and is always right. 

I didn't understand this expression growing up, but I grew up very competitive. My dad raced boats, founded a B.A.S.S. club, hunted for sport and trophy, ran his own business (plus a few start-ups) and faced more than one tragic failure.

At first I thought "The customer is always right," meant there's nothing to be gained from arguing with a customer -- which I quickly figured out is generally true. But the deeper meaning, at least to me, is: I am not you. To use Adam Decaria's expression, “Others are not just like you with a different face.”

The job of a good salesman 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, and how a product might help them find what they're searching for. It's a simple thing, but it took a long time for me to get it.

Zu designs products that are an expression of its people, and while I love our designs, I don’t presume you and I 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's something that fits the values of the large majority of those who find our stuff attractive. 

We're not pushing product, we're trying to make friends that will give our handiwork a try. We're creating and manufacturing products that express a unique position on tone, hinged around Zu’s way of looking at playback, music, and the art, form, and architecture of the electromechanical and electrodynamic.

We hope you like what we do. 

Posted on August 18, 2013 and filed under Commerce, Company, Philosophy, Show All.

Can I visit? Does Zu have a showroom?

Please, come and visit. We have an open door Monday through Friday from 9:00 a.m. to 4:30 p.m. mountain standard time. We have been known to close for holidays and big powder days, so please call a day or two before (mostly so we can clean up a bit).

Zu is located in the Ogden Commercial Industrial Park and is a production and manufacturing facility. Due to the nature of work, noise levels, and efficiency of production, we do not have a showroom at the factory (production took it over about a year ago). Those that would like to visit, and we hope you do, should give us a call and schedule so we can spend proper time with you, pick you up from the airport if needed, and arrange some listening time with Sean, Gerrit, or Dane. Scheduling with us also gives you the chance to catch some good live music- Ogden really has a great live music scene.

We're looking for a Zu Store & Showroom site in downtown Ogden, but nothing yet. 

Posted on August 18, 2013 and filed under Company, Show All.

What is Zu’s take on the future of hi-fi?

There's been so much talk about the future viability of high fidelity playback that it’s 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.

On 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 sign up for obsolescence.

“The iPod is a gateway drug.” —Nelson Pass

What Zu is seeing is a return to the fundamental enjoyment of music—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, it’s leaderless and burdened with assumptions.

Yes, it’s the end as we know it. Hi-fi is being replaced. It is being displaced by systems and devices the new music lover can live with, systems that are capable of recreating the sonic events that move them.

No, it wasn’t hi-fi that saved vinyl. It was hip-hop, the DJ, and the techno scenes. And now it’s the kids, those growing up in the Great Recession and those that yearn for real things and value art. This new generation of music lover is about the DJ, 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. Zu is expanding hi-fi and refuses to pander to what it was in the ‘80s and ‘90s—not all that pretty when stacked up against the golden years of audio.

The original searchers for high fidelity recording and playback embraced sounds in all their forms. The original audiophile 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, we turned 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, to accessibility 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. We’re trying to grow hi-fi. 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.’ We’re 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 its 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 Debussy, Hank, Elvis, Dylan, Beatles, Bambaataa, Lydon.... 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.


Posted on August 18, 2013 and filed under Company, Philosophy, Show All.

Why such strong LOVE/HATE opinions about Zu?

We don’t play games, we don’t kiss-up, we do what we like, and we are finding success and building a great company. Because we have no intention of doing it like its been done for the past forty years, Zu simply rubs the majority of invested hi-fi guys the wrong way. We see playback differently, and thank god we do.

We've also been very successful where so many others have failed. Zu threatens the established channels of commerce and anytime you threaten someone's livelihood, you're going to get strong push back.

Add to the above mankind’s competitive nature (all of us want a shootout; a winner and a loser) and that kind of stuff gets attention. We love the game, it's nothing we’re hiding. We love bangin' bars, swappin' paint, and roostin' the shit out of buddies on the race track -- and we don't mind getting roosted either.  We love the competition -- dirt, street, water or otherwise. But here in the domain of playback and music, it's not that kinda competition, is it?

Tests, measures, and experts have been the holder of truth since the '70s. Even though Zu's founder grew up during that era, the main tenets of his company are closer in belief and methodology to the original pioneers of playback -- placing the ear and the individual's sensation of tone as the final arbiter of sound quality.

Because of this, we have a difficult time discussing methodologies, tests, and measures with leaders such as John Atkinson (who we respect, no dis here). Conveying where Zu places value relative to the scientific understanding of music reproduction and the quality assurance systems for consistency is difficult. How can Zu get along with a competitor if neither of us is racing on the same course? 

Zu doesn't claim to have the best sound, but we do think we have a clear and distinctive voice and we think the products we make are likely the best for a majority of music fans. Still, there is no absolute sound in playback and there is no owner of fidelity.

Zu’s position on playback is not conventional and not in our heads. Friendly discussions about tone and the art of playback come up all the time. Let’s all stop talking about the best way and be more like a tape op.

Generally, when an artist or musician is recorded, tracked, mixed, and mastered, the whole process is done with a new creation in mind -- not a reproduction. This process has little to do with the real event -- unless you're a recordist after natural soundscapes such as the interplay of a forest’s ecosystem late at night or the tolling of the prayer bell in some remote, Tibetan monastery. Even in those cases, the mind’s ear is on the recreation of the capture as a new event that compels in a different, yet related way.

The point is, playback of music is an art. 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 (i.e. Elvis, the Beatles, Gram Parsons, John Lydon, The Clash, The Books.) What matters is how a product performs within a system to move the invested individual emotionally, ultimately connecting a familiar, desired, and anticipated response.

All of the great classic works on the physics of sound and sensation of hearing, put emotion and our response to tone as transcendent of tests, measures, and logic. Musical scales, reasons, and relationships are definable -- 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 (i.e. Ohm, Helmholtz, Jeans, Rayleigh, Lamb, Olson.) All place our sensation of tone as transcending understanding -- our individual 'ear' as the final arbiter.

Posted on August 18, 2013 and filed under Company, Philosophy, Show All.

What is tone?

Tone is quality in pitch, harmonic composition and time, exhibiting linear dynamic behavior in the complex intensities of music.

Tone is not how something measures but how it sounds.

The word was made popular (though in its German form, "Tonempfindungen") through Hermann von Helmholtz’s groundbreaking work Sensations of Tone, written well over a century ago.

The correct usage has survived and flourished in the music world, particularly with guitarists.

Posted on August 18, 2013 and filed under Technical, Show All.

What is burn-in and why?

The practice of burn-in originated with the commercialization of electronics about a century ago -- and it makes a difference to nearly all things associated with the audio system. Some things about burn-in are easy to grasp, but they are the exception.

As burn-in relates to sonic fidelity, nearly all solidly burned-in audio equipment and devices (including cables) sound better than the same device when new. Many feel that even loudspeaker cabinets, like musical instruments, need years of play to sound their best. Certainly all audio cable or wire impacted transmitting and receiving systems are influenced by burn-in.


We’re not totally sure. There are so many variables -- and very little conclusive, in-depth scientific research can be correlated meaningfully.

What We Learned

In 2001, Zu began tracking and investigating the effects of signal and power on various cables and loudspeaker systems. During the course of this investigation, we stumbled upon a few tricks and processes 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 dielectric 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 it has 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're still not prepared to release any new data or findings. We can only relay that we fully believe in the sonic effect we hear.

How real and how much difference is there?

Significant in most cases. So significant, that we made some heavy investments in exploiting the phenomenon.  

While running extreme soak tests, we found that through long hours of play, there is potential to improve wire, cable, component, and loudspeaker drivers beyond what is possible with a traditional burn-in or break-in procedure.

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. There were a few accidents along the way -- a burnt rack of power amps, cooked voice coils, and shredded driver cones -- but the time, money, and setbacks were 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.

What Burn-In Means to Zu

Zu’s first big indicator that burn-in was essential to get our stuff sounding its best was when one of the original pair of Zu Druid loudspeakers was shipped to Don Garber of Fi in New York.  He liked 'em but never loved ‘em. A year later, Zu had them collected and went about checking them over. The consensus was that Don should have loved ‘em, and that someone at Zu must have screwed something up, or that there might have been a transformer compatibility issue. 

Everything checked out like new -- and that was the problem. A year of play with very low power had done nothing to break them in. 

It was then that we realized most users are not going to lean on the speakers the way Zu does. After thinking about it for half a second, we realized that our whole concept of how our speakers were going to be broken-in was not possible for the vast majority.

Concert level playback -- concert after concert after concert -- meant we had to get a soak and burn-in system up and running quick. 

On September 31, 2006, Zu committed to running all loudspeakers though our factory burn-in system. This aging/burn-in treating process ensures Zu loudspeakers will sound their very best without the user having to burn them in with specified program material or at high playback levels. A new pair of loudspeakers that have been hit with factory burn-in process will reach peak performance within a very short time -- a week or two in the summer months, two to four weeks in the winter as wide temperature gradients seem to cause delayed burn-in.

The speakers will sound better as time passes, but users really shouldn't sweat it. Just play as you will!

We're excited about our burn-in process. Since adding it as part of the manufacturing process, our 60-day satisfaction guarantee refunds have gone from roughly 6% to less than 2%. The comments from customers went from, “They're good, but a bit restricted sounding,” to, “Man, these things rock!”

No, we’re 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.

This difference was confirmed in the first quarter of 2011. During the fourth quarter of 2010, we introduced the Omen series. As a cost cutting measure, we announced that this line would not be getting factory burn-in. This was a mistake and our return rate rose, hitting 8%. Lesson learned.  All Zu loudspeakers now have factory burn-in.

2013 Burn-in Program

Beginning 2013, all Zu loudspeakers receive 600 hours of near soak test level burn-in. This new system and schedule helps to ensure your new Zu speakers will wake up and perform quickly -- assuming that the room and gear are working well together, and you're playing the loudspeakers for roughly four hours a day, at normal daytime listening levels. 

Live sound pressure levels are not necessary -- the burn-in program takes care of this phase for you -- but doing so will shorten the time it takes for your new loudspeakers to relax and open up. This is especially true if the program material has a large, dynamic, full-spectrum power density.

The 2013 burn-in system and schedule is music based and dynamically varied—low levels during production hours, cranked to “11” for the remainder of the day, and non-working weekends.

(And if you're wondering, we are in an industrial park with a liberal 24 hour workday noise ordinance.) 

Burn-in is done in matched pairs to the complete electromechanical systems (drivers, cable harness, connectors, high-pass network). This portion of our manufacturing and forced aging is also an important stage of our quality assurance program. 

The burn-in is completed before final assembly, where guts meet cabinet, and final tests and measures are performed.

Outside Conditions That Affect Fidelity

Shipping, handling, temperature, and prolonged duration of inactivity can cause fidelity disruption of all Zu loudspeakers and cable. 

After Zu products are transported (and especially if they pass through cold temperatures), they take a bit of time to settle in and come to life. This is generally true of dynamic loudspeaker systems, but we have found these factors dramatically influence the sound of ours. 

How much time? 

One to four weeks. One week or so when warm and shipped by truck, and up to four weeks if the transit time is long and the temperatures are very cold.

Why does handling, temperature changes, temperature gradient rates, and duration of inactivity cause fidelity disruption? 

There are many reasons, some known some speculated.

In our loudspeakers, the major electromechanical subsystems seem sensitive to these influences and proportional to the level of success realized in each of our loudspeaker design tenets: 

  • high-efficiency/huge dynamic range
  • wide well behaved bandwidth from a full-range driver weighted on the human voice
  • doing so sans crossover or other filters on that wide-bander

We do what we can to ensure a good first sonic impression and to maximize short and long term music fidelity -- our new 2013 burn-in program is proof. 

If they don’t sound awesome right out of the box, please give them time to loosen and warm up. Go ahead and call us—we're here to help you get great sound. 


Posted on August 18, 2013 and filed under Technical, Show All.

Is there quantum tunneling in cable or magic boxes?

No, but it makes for great marketing—if you think your customer is a dope.

I do think we are at the cusp of the next technical revolution, one that has nano engineering leading the way. As science advances in what we know and can do at the atomic level, we will see huge progress in audio and everything else. And to get a bit philosophical, I think humanity’s creative prowess and appreciation for music is a clue to the human awakening.

Is mankind's understanding of the atomic world correct? I don’t know, I’m not that guy. But if we look back through history, you would have to say it’s unlikely. We only model as boldly as we think. I know that I prefer wave mechanics and talk about the electronic in terms of standing waves—more the Schrodinger view (it 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 to audio fidelity and real solutions for the electronic. Since the days of Rutherford, Born, Schrodinger, Heisenberg, and others, 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 1920s, when the Copenhagen Interpretation of the atom was conceptualized. We're still struggling to wrap our minds around these concepts and mathematics.

Despite being at odds and less than unified, Wave and Particle Mechanics, Matrices Math, and Quantum Theory are the language through which fundamental itsy-bitsy physics is to be comprehended.

As all of this applies to audio and making informed decisions based on marketing... well, you have to look past the hype. Personally, I blow off products where claims are clearly bullshit, regardless of how the product performs. “I can’t get behind a fat ass!” to quote William Shatner.

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 using those nifty ears), not the theoretical, that have formed and guided audio freaks like you and I in our handling of electric and magnetic phenomena.

Posted on August 18, 2013 and filed under Technical, Philosophy, Show All.

How are tests and measures important?

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.

Tests 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. Measuring, and the scientific procedure as a whole, 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 why.

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 manufacturer or lab or system will vary, making cross comparison very difficult.

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


Posted on August 18, 2013 and filed under Technical, Philosophy, Show All.

Is my system only as good as its weakest link?

This notion is 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. That's why we call them: “Loudspeaker System,” “Playback System,” “Sound System.”

Like any complex system, the playback rig and its environment cannot be fully modeled without an understanding of its components, relationships, and acoustics. But this is not to say that evaluating devices sonically can only be done by those few with profound understanding- anyone can.

Check out How do I evaluate changes in my playback system? for additional insight.


Posted on August 18, 2013 and filed under Philosophy, Technical, Show All.

How to evaluate changes in a playback system.

First know that it’s your system and that playback is art. There is no such thing as "absolute sound" or "perfect fidelity" and not everyone values the same things in music or listening.

Some facts to consider:

  • Playback systems function as a system and any change within it will very likely affect how you hear it. A change anywhere within a system can and should impact the system’s sound.
  • We can never assume that an assembled array of playback equipment, or any single device, is perfect.
  • The perfect recording does not exist.
  • Things change over time.
  • People are easily fooled.
  • Each person listens and hears differently.
  • All systems are different and a device under test will perform differently in them.
  • Systems will sound different at different levels and most people tune for a particular listening level, music, or coloration emphasis.
  • Unless you are the producer, recording engineer, tracker, mix guy and mastering man (rarely even the same team let alone the same person) responsible for the recorded material, with a vast understanding and experience with your recording and playback systems, you can never know the recording’s nature and accuracy. Besides, isn’t music about fidelity of emotion? (If you roll in at a Zu demo, chattering about how you know what a particular recording is supposed to sound like… well, let’s just say it’s hard to take your comments seriously and it’s possible that we’ll call you out if you start stinking up the room.)
  • General listening-specific assumptions can be made after a large enough sampling of systems and observers has been taken. But these are only relevant to the state-of-the-art of playback systems within their sampled generation. Loudspeakers that are known to sound good in today’s systems will generally sound bad when used within a system from the ‘40s or ‘50s. That is not to say a loudspeaker from the ‘40s will sound bad in today’s systems—it’s all about the matchup and knowing where you the listener places value.

So, acknowledging all of these things, how do we approach the evaluation process? 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 recognize 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.

Cable Evaluation

Zu makes cables, so let’s take a look at cable evaluation. If observers are really trying hard to hear a difference between cables because they believe the difference will be subtle, this will compound the potential for outside or psychological influence. If the observer has a predisposition towards a model or brand, 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 second time listening to the same material- the “second set”- results in increased awareness by the observer, particularly after a brief calm or distraction. Therefore the second device tested is usually psychologically perceived as sounding better.
  • Observers usually relate a small increase in amplitude (1 – 3dB) to increased fidelity, especially if the cut is played at a level that is lower than you would experience it in real life (low-level listening is distortion). The closer the intensity of sound is to what we expect, the better we think it sounds.
  • A demonstrator may use playback of recordings that are known to work with or against the bias.
  • A demonstrator may use playback with equipment that works with or against the bias.
  • Observers are influenced by the demonstrator. Combine this with the “second set” phenomenon and the demonstrator can easily skew data.
  • Rumor, reputation, price, looks of the device and personal investment effect our values.

What a Fair Test Looks Like

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, is best- as long as the observers keep their notes to themselves until the completion of the study. But even then, the whole system thing is pretty massive.

A simple cable test should consist of two or more observers and a controller, all of whom 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. 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.)

Then there is the very large topic about recorded material and how it factors in, but a song or two should be selected and the set 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.

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. Observers are not allowed to know which cable is under test or know the device cycle.

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.

All of these factors combined should make for a fair test.

But the bottom line is that you must search for your sense of sound and trust yourself-you know what you are looking for. If you don’t, you won’t find it in the forums. 


Posted on August 18, 2013 and filed under Technical, Philosophy, Show All.

What are Zu's political leanings?

The individuals that make up Zu are red blooded ‘Mericans. We that think what Washington, Jefferson, and all the other U.S. founders did was genius. We're not always happy with our leaders -- we don’t always agree -- but we are proud of our system. It's a system where 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
  • Individual responsibility
  • Equality
  • Solid education throughout the nation (language, math, science, history, art, music, and constitutional understanding)

With these fundamentals, people can correctly wield the power that is innately theirs, and have a solid foundation from which to explore, advance, and live as a community.

Since the end of World War II, it seems that the leaders of the U.S. have had a predilection for becoming deeply involved with other nations. This is something the majority at Zu do not necessarily agree with. We're much like the founding fathers, the majority of whom strongly felt we should avoid getting entangled and burdened by geopolitical alliances.

However, the modern age is a little more complex.

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 -- and the individual looks after the community.

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 talk politics and religion (not regarded as polite in most books) then go for it. My views are my own -- and Zu, like Elvis, is officially on record as only being here for the entertainment. 

Posted on August 18, 2013 and filed under Company, Show All.

What makes Zu loudspeakers so good?

(Or, “A bit of ‘us vs. them’— for perspective.”)

For us, good loudspeakers play all genres of music with real intensity and are dynamically expressive of tone and texture, all with convincing tone. Good loudspeakers put the music out in a way that hooks you and pulls you in-- or rips your guts out. They almost force your attention and they make you want to live life bigger, with greater effect.

Today those that want full and hard hitting efficiency 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 engaging. 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 is whacked.

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 engineer’s 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 criterions 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 we believe that you’ll notice the clarity, aliveness, and presence—even if you are used to much more expensive brands. This might take some time if you have grown up with dicked-up modern hi-fi speakers, but we think most of you that live with our stuff will come around—you need to do more than just taste the “Zu sound”.

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 the conditions of music, and have little relevance to how it might sound in a living room. Technically, bandwidth does fall within amplitude’s 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 that 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.


1.     We’ve got Zu’s 10” high efficiency, high power handling driver platform.

Zu’s high efficiency full-range 10” loudspeaker driver platform plays nearly all the musical scale with stunning dynamic range, and with linear behavior, creating such a natural and vivid sound that you will no longer focus your attention on the speaker, just the music.

But with high power amplifiers saturating the market, why would anyone looking at loudspeakers consider high efficiency as an essential design feature?

Well, in addition to the technical reasons stated, high efficiency is necessary for low power amplifiers; and the ‘Zu + tube’ combination, especially single ended triodes, is certainly addictive. Same holds true for the more interesting solid-state designs, most of which are coming from Nelson Pass’s head and hands.

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 you 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 triode up to 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 (twenty watts) 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, shove from your favorite electric guitar recordings, or crescendo from Wagner.


2.     There are no crossovers sucking life out of the music (like 99% of today’s loudspeakers).

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 that 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. It was during this time that acoustic suspension speakers were introduced. Consumers began to gravitate toward small speakers that gave the impression of big sound. 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 to real levels knows it’s a long way from lifelike. For over fifty years now it has been the same: 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, Westinghouse, and others: using paper based cones, even leaning heavily on the exceptional 1930s RCA research and designs. Not being afraid to design and produce our 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. We do this without filter parts injecting noise, robbing efficiency, and sucking the soul from the music.


3.     Zu-Griewe driver/box/acoustic loading technology, developed by Sean Casey and the late Ron Griewe, allows improved driver-to-room coupling, fidelity, and bandwidth.

Let us introduce you to 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, then distortion is increased. Bass-reflex speakers are infamous for this, as are transmission lines and acoustic suspension designs.


4.     Zu’s own B3 internal cabling archetype and solderless termination offer significant improvement in amplifier / loudspeaker interaction, increased resolution, and reduced noise.

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 pays 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. They also 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.


5.     Our commitment to in-house manufacturing ensures quality, consistency, and long-term viability.

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 type of business. Zu, on the other hand, makes audio gear with performance and build quality first. We trust that if we build the best products, with a duty to community, sales and success will follow. Imagine, products selling themselves....

To maintain our inventiveness and realize our 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 and 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 manufacturing. 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 every day of its and your 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. 

Posted on August 18, 2013 and filed under Loudspeaker, Philosophy, Show All.

What is a full-range driver?

A loudspeaker driver is an individual transducer that converts electrical energy to sound waves --generally incomplete without the supporting enclosure and tuning system that together make up what is known as a loudspeaker system (or “speaker” for short.) 

The loudspeaker driver is nearly always of the electrodynamic type, consisting of a frame that supports a magnetic circuit, a cone, 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 (musical terms, 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 as having an in-room bandwidth capacity of 35 Hz to 12 kHz -- roughly eight and a half octaves.

The 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 history, please see "Wannabe Curation Communication" listed under "Forum Claptrap". 

Posted on August 18, 2013 and filed under Loudspeaker, Technical, Show All.