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.