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Zu on Zu

I’ve just read through the bottom third of a very, very long and passionate thread here regarding Zu speakers, generally centered around whether or not our designs employ crossover networks or not. After doing this, and with a great deal of restraint not to write you all off or retort “screw ‘em all” (Yes, I try and keep a clean mouth, had the other word there for a bit but on reread... But honestly, I might have to use such words to keep the attention here.)

I feel a nice long ramble coming on but before I open it up full throttle all cross-country like letting it all ride, let me make a few brief points. I also know that in order to accurately communicate we must use technical jargon and it is also evident that the majority I will be communicating with are concept-oriented and likely do not have a fundamental background in loudspeaker design or physics. Very likely you are getting your info from that STD cookbook—how to build iffy loudspeaker by VD. Big mistake if you ask Gene Czerwinski, Lars Nordland, and others that have made loudspeakers their life's work. If you haven’t at least studied Harry F Olson (Hey Lars, Harry was a Swede too, born in the US though, didn’t have your cool accent) and you are posting your opinion as acoustic-physics-based you should stop, do more home work and come back ready to play ball. So, this will be wordy, technical, maybe even problem/proof centric, we’ll see. Yes, this is a pain in my butt, it is a big distraction, the few hours that are going to go into this are stolen from my family and I’m pissed about it. If this were during the work day I would still be pissed because I got better things to do, this is not a real contribution to the art of audio, my contribution should be realized in product and systems, not Q&A. But there is a need and if I let the anti-zu thing go too far it will most certainly hurt revenue and thus the mechanism through which Zu’s ideas are realized. It is also difficult as I do not think in a linear fashion. Ideas are expressed in my mind as if they were on a stage, roughed in concepts seem to just take shape, the various parts interplaying and emerging simultaneously, and I am able to see the problems in my head, work them out virtually. I suck at math generally to say nothing of my English and spelling skills. Going from thought to pounding on this keyboard is like flying along at 170 MPH and then having to slow down for a school zone. I also drop words, sometime complete ideas, hands are always behind. So, read with care, realize this is not what I like doing and feel free to NOT expect more of this blather here. We will however address the wives' tales, misunderstandings and music over at ZuAudio.com. We hope to give the Zu guys some proof support and also hopefully convince some of you ATC and Klipsch onwers to give us a try -- okay, at least respect what we have created. By the way, you ATC guys, I have my one secrete sauce and rebuild tweaks for their very cool 3” dome. It’s three hours per driver, shop rate is $60 / hour. Satisfaction guaranteed. On second thought, I’ll be asked a bunch of questions, let’s come back to this if Zu really is just a fad. I do think that is one of the top 50 drivers of all time. Love the thing.

Cynicism is a good thing. I don’t care if you don’t like the Zu sound, I don’t care if you think you can do it better, I don’t care if you only like to listen to unamplified triangle made from C76200 alloy played only at night 100 miles from the closest paved road—I don’t care. But when you armchair engineer my stuff and rag on my customers, and do it with this “I don’t mean to offend” attitude but you really do—ya, this gets to me, at least it did tonight.

There are a ton of things I think Zu should now begin to talk about. Finding the time for such writings will be difficult but we are committed to it. For now I can only briefly address the whole crossover thing. I will come back to it and give it a proper writing with Adam to run proofs and math and to pick up what I let drop. I swear we will do it in the very near future.

Enough all ready. Zu Tone, Druid and Definition loudspeakers do not use a crossover network.

“Crossover”, like “speaker” is short for loudspeaker, is short for “crossover network” as applied to audio. Webster’s New Universal Unabridged Dictionary copyright 1996 defines a crossover for audio networks as: An audio circuit device that sorts the impulses received and channels them into high or low-frequency loudspeakers. This is a very non-technical definition but gets the point across. Our full range driver is directly connected to the binding posts with nothing more than cable, designed to reduce reactive loads, from voicecoil to input terminals. There are no devices of any kind between. Simple right? No, many think that the dynamic behavior of the drive unit must be factored in. I agree, the engineer must consider this but it is not part of a defined crossover though must influence a builders selection and execution if a crossover network will be used. Since our driver is an electrodynamic coil-in-static-flux type it has reactive components. These can not be eliminated. We tried many new types of coil windings on our motor, trying to first reduce the inductive rise without sacrificing dynamic range while also looking at how to increase electromagnetic densities. After a lot, or is it alot, of this and that, success and flat out failures, we ended up with a basic down and back, windings on top of former voicecoil. This voicecoil is rather big for a drive unit with a bandwidth of 8.5 octaves in room response, 5/8ths of an inch long and 2 inches wide, immersed in a high density magnetic (B) field uniformly covering the complete coil, static B field density has a practical usable length of 1 inch allowing for linear full coil immersion operation of roughly 1/4”, 1/2” peak to peak. The drawing of the motor assembly resembles a neutral hung design. Consider now that we have a mechanical xmax on the suspension system, spider and surround with a gib factor of about 20 / 80, you can see that our drive unit is quite capable of very high SPL levels, very linear dynamic behavior, reduced inductive rise as the coil only sees a shunt or little static B field at full band power levels in the 100 Watts RMS area. Full bandwidth thermal dissipation capacity on our Zu260FR/G2 is 200 Watts, 400 Watts if used with an active high-pass set at 50 Hz (2nd order) for those of you who might find yourself using them for DJ monitoring. What, none of you are in to the DJ scene, man you really are missing out. A motor, which accounts for all the electromagnetic functions of a driver, must also be modeled with the transducer's intended impedance matching counter part, the thing that couples to the air and that things suspension, and visa versa.

I also noticed that somebody here is a big active crossover fan. Cool. This has real promise and is how everything in pro is done. While the digital technology has finally come around well enough to make decent sound I personally feel that for great texture and tone the main transducer should cover as wide a bandwidth as possible keeping that first crossover point below the modern third octave (64 Hz point give or take a bit). But this really is a completely differnet topic, we are talking about home audio applications, not OzFest stuff where active crossovers and crazy solutions are essential. For this club style party we played at HE2006, we ran our druids with the Crown I-Tech power amps. A two way system with a LR12dB/ at 52 on the Druids, BW6dB/ at 28Hz on our Druid riser subs. The room had a big fat boom in the thwack range. We really lit the system up for DJ Presto at about 2:30 AM, man was that cool, crystal clear, hard hitting sweet sound at concert levels that would make even Gordy Johnson cry!

Speaking of the show. I had this 20 minute talk with a Bose guy. I really wanted to say, but didn’t, hey, what cool stuff have you made anyway, spending ten times the Chinese made product costs on market, get the flip out of my room. Instead I had to listen to his absolute understanding of cone modes and break up. This is why you ain't gnu see anything cool from Bose anytime soom. This is a lead-in really. Here is an actual quote by an earlier blogger’s post: “I too am sure that nothing aphysical can be happening---if only because that would not be allowed by physical laws.” Really, somebody wrote that? Not sure if this was a Zuid or a Zu is a fad guy, either way we can’t think like this. If an anti, say something that sounds kinda good, use the word physics to back you up and move on. That’s a load of crap. First, we humans know little more than that friendly little black ant crawling under your door. Don’t they call ‘em piss ants or something. Really, you take any branch of physics, try and take it down to a fundamental level and see if the whole thing doesn’t fall apart. Yes, Newtonian physics let us get surprisingly close to the average model of many things, let’s us measure and repeat basic stuff. But the further we dig the more we realize we are nothing, understanding virtually nothing on a base level, only knowing how to repeat and model not truly getting the whys of it all. Physical laws are discovered, they do not allow or disallow, they behave in a particular way under particular conditions, understanding being based on the particular way you measured and model the thing. Again, you break stuff down far enough and new models and behavior emerge. The physics student that does not subscribe to absolute will be find himself in a position for discovery and contribution with greater frequency and magnitude. Me, I’m only a physics major drop out, largely self taught in acoustics starting with passion at the age of thirteen. Favorite reading back then was Olson. If a Zu guy said this now you know why I started jumping up and down when I read it.

Physics, it’s super cool. It’s our chosen discipline here at Zu. We hope to add to the knowledge base, not simply follow everyone else’s models. And when it comes to loudspeaker and cable design we want to lead, we intrinsically question others models and proofs, preferring to go it on our own, discovery is still a much bigger fixx than recreation.

Give us a break, we are a bunch of guys that love music and sound just like the rest that post here, bootstrapping our ideas to life. We are just asking for a bit of time to mature, get our communications together, figure out marketing a bit, find ways to get the product in your home for a listen. If you don’t like it, no big deal. But if you are pissed off cause you think you should be where I am, then get busy man. Make it happen.

Look for more at ZuAudio.com in a few weeks. Really, we are committed to the communication of technical assays, if for no other reason than to save our supporters from going crazy here at Audiogon.

I’m tired, need to see my wife, get some lovin, eat breakfast with the kids -- at home and not at Zu.

Later,

Sean
sean_zucable

Showing 11 responses by 213cobra

213cobra
885 posts
 
Onhwy61,

The thread you refer to began as a query on Druid bass response. At some point someone raised additional topics which prompted the crossover/crossoverless discussion. The energy in the latter third of the thread regarded merely getting acceptance for a truth -- that Zu doesn't use crossover networks in their speakers and that the Zu FRD sees the full-range signal. We didn't say everything designed otherwise is "wrong." I did say that everything that has a crossover has a distinct quality to its sound that I think is a disproportionate source of recurring disatisfaction among audiophiles. My advice is, with the emergence of a viable and tone accurate FRD from Zu, and progress in this direction from others, to choose from the realm of crossoverless speakers if you want to make progress in this hobby and vault out of the perpetual disappointment box. It doesn't matter to me whether you disagree with that or not, it's still my advice to anyone who asks. And those of us who own Zu speakers believe that Zu is the most advanced of the vendors who have pushed in this direction.

As long as you don't try to distort what is true about a speaker's configuration, I and others here have no quarrel with you or anyone else preferring another speaker. The recurring issues of contention in Zu threads are instigated by the claims of people, who haven't heard the speaker, that for one reason or another it cannot behave as claimed by us owners, or that the speakers are configured differently than described. We have been generous with our time in explaining the details that will give you an understanding of Zu's speaker architectures, with or without having heard them. You may dislike the speakers and remain unentangled in arguments, but you cannot misrepresent them and expect to avoid a discussion.

I already covered the FRD issue -- At a time when the 20Hz - 20kHz audio band idea was established as a standard for electronics, cassette decks were considered "full-range" with 40Hz - 13kHz response when reel decks were 10Hz - 25kHz at some speeds. Even multi-way speakers that topped out at 16kHz have been considered "full-range." FM radio, which can top out as low as 10kHz but should go to 15kHz, has been considered "full-range." Some people consider full-range to extend hypersonically. The term has no fixed reference in audio. Hence, in the absence of definitive agreement, use "wideband driver" if you want. No one will care if you do, but the industry vernacular will also support Zu's use of FRD for the current Zu main driver.

Phil
213cobra
885 posts
 
Barktok,

No, Zu speakers are not exclusively directed at the low-wattage tube amp user. The high efficiency and easy drive characteristics may be ideal for that, but these speakers have a power-handling capability that is just about unique to the genre of high efficiency speakers. Their dynamic capabilities are impressive regardless of music type, and as Zu demonstrated with their rave DJ party in Los Angeles, that includes using their speakers at high SPLs with several hundred watts available to each speaker. I've heard them with big, meaty, McIntosh solid state amps and would consider that option, along with my SETs.

Phil
213cobra
885 posts
 
Drubin,

The reason it takes some people an extended period of time to adapt to Zu speakers on first listen is the necessity to unlearn much of what you have been conditioned to accept. Most people -- most audio consumers -- haven't ever heard a phase-coherent speaker, nor one with uniform transient characteristics up and down the frequency range. Nor have most heard a speaker that doesn't place a crossover in the region of information density in a music signal. And most haven't been exposed to a speaker with the dynamic life, the jump factor and fast rise that you get from Zu speakers. And many of those that have, have not heard these factors from a speaker with Zu's tonal accuracy.

The product design biases of the industry have conditioned listeners to accept disjointed sound, and pinched midrange in the crossover points. You've been listening to many phase -incoherent speakers, and high variability in transient behavior, top to bottom. When these attributes have been sold as normal, hearing the absence of them can be disorienting. It takes some people minutes and others weeks. But when you hear it you will understand the result, even if you need more time to investigate the reasons.

Phil
213cobra
885 posts
 
Bartok, Kana,

The Soundstage response graph on Druids is inaccurate, bogus really. They adhered to a Canadian measurement standard that required the speaker to be suspended in mid-air. Zu sought an exception from the standard because the Druid requires floor placement and precise gap adjustment for the Griewe model to work. Soundstage made no exception and measured the speaker, showing both dramatic fall-off in bass response (of course, the floor was missing!) concomitant anomalies extending up to the midrange, in the absence of the Griewe model working.

The speaker's sound bears no resemblance to that curve, unless you hang Druids a few feet off the floor, of course.

Phil
213cobra
885 posts
 
Yeah, Kana, I can't see that graph or the article well enough to know how the graph was derived. Suffice to say that you can't just wire a Druid up on a bench and measure it without knowing how to set it up.

What it behaves and sounds like is plenty of energy down to high 30s and then rapid fade below, preserving high articulation down to its lower limit. The midrange is affected by the Griewe model working, and is quite smooth and open, but there is some coloration that is tuned out of the Definition completely.

Phil

Phil
213cobra
885 posts
 
The Griewe model is essential to Druid bass performance. I'm not hearing a 150Hz dip corresponding to the graph. Yes, classical music has a lot going on there, and in my room it's all present and accounted for on Druids.

The FRD doesn't derive its bass extension from direct proximity to the floor. And in fact you realize you are hearing the lower tones seemingly from the entire unit and not from the cone. The height of the FRD imposes no bass limitation, and in fact the Griewe model is what puts the driver up there in the first place.

Phil

Phil
213cobra
885 posts
 
Smeyers,

I don't think anyone here means to offend. So if you can cite one or more posts or comments from Zu owners that could be inferred as "arrogant and demeaning" by readers of a Zu thread, please do so and the group will know what to avoid, thus staying within the sensibilities of the community. Fair enough?

I read a lot more here than I respond to. My observation over many threads is that the detractors of Zu products who have not heard the speakers are generally the violators of civil discourse here. However, I haven't really been counting. It's an impression.

Phil
213cobra
885 posts
 
Onhwy61,

I think you confuse offense and defense. Zu owners are engaging the market with what we've learned, not defending decisions already made.

You presume too much if you think that design preferences determine what I like in audio gear. I approached Zu with skepticism of what the result would be, knowing that prior crossoverless implementations have been unsuccessful. I was willing to buy my first Zu speakers unheard and unseen, because I have the means to risk it, and I have the experience to triangulate what I can expect. Even if the purchase failed, I knew I'd learn something. Despite a disappointing history of attempts to build crossoverless speakers for high-end audio, Zu looked encouraging due to the development of the FRD. However, everything else I've ever owned and enjoyed in a loudspeaker contained crossovers, with many crossoverless alternatives which I rejected.

Similarly, I've owned solid state, push-pull tube, SEP, SET, OTL amplification. I currently use SET amps in both my systems but that doesn't prevent me from admiring, lusting for and considering McIntosh MC1201 transistor, autoformer-output, 1200w monster monoblocks. I wouldn't have expected to like them on paper, but they are sensationally good amps and couldn't be more different than what I own now.

I had a design bias toward belt-drive turntables, but my mainstay Luxman direct drives have outlasted all challengers of the belt-drive kind. I was predisposed to LCD for HDTV but bought plasma instead.

I bought Zu speakers at a penultimate moment before purchase of two systems built around Sonus Faber Cremonas, which are multi-driver and use crossovers. No doubt, if I had not found Zu, I'd be as enthusiastic of SF if mated to the right amplification, and you will find if you research my posts that I have recommended Sonus Faber and Reference 3A to others here, along with Zu.

So your presumptions of me are uninformed and in error. I have in fact practiced what you preach, for nearly 40 years of hifi purchases.

Once again, I and most here do not have any issue with someone who has listened to Zu and does not like them. I have no argument with Boa2, for instance. The people whose credibility has been attacked are those who challenge or attack Zu products while having never heard them themselves. That's almost always the bone of contention here. That is not a matter or expression of zealotry. It's a simple matter of working to keep the facts straight.

I have to ask, because if ever answered, I lost track: Have you ever heard Zu speakers, Onhwy61?

We who own Zu products are not condescending. We don't think we're better than you and I haven't seen any suggestion of such a proposition. We don't care if you hear the speakers and don't like them. We do care about misrepresentation (and by the way this is true for any other little-known product I choose to support) and we reject the doubts of those who undermine the discussion with claims uninformed by actual listening. Questions on the other hand are welcome. You can see a wealth of posts by Zu owners explaining to people considering them, what to expect, how to optimize set-up, and how the speakers work. It's just basic user knowledge-sharing. And if you follow our various postings you can see similar effort put into other products as well. It's not a Zu-specific phenomenon. I and others here are patient in explaining how to get better sound, as our posts should amply indicate.

As for happiness, I haven't noticed any deficiency of it in my life. And the combination of Zu + Audion amplification + the magical Denon DL103D or a good universal disc player like the NAD M55, used as conveyance for putting music in my home, only raises its incidence.

Phil
213cobra
885 posts
 
Onhwy61,

No, it's not nonsense. Your dismissal is. First, it's less and less common for audiophiles to actually know what real instruments sound like. More and more people in this hobby are short on or even bereft of significant experience listening to live, unamplified music. But let's assume you're not among them, nor is anyone else on this thread.

No speaker is a perfect reproducer. Hence, psychoacoustically, we allow the suggestion of fidelity by hifi to inform an illusion of fidelity that we infer from what comes out of the speakers. If you have been listening to speakers all your audio life that contain crossovers, multiple drivers with division points in the middle of the major spectrum of music information, and other design attributes that introduce phase incoherence, transient inconsistency, tonal aberrations and confused spatial portrayal, BUT the basic frequency linearity measures and sounds pretty good, then you become conditioned to believe that the suggestion of fidelity that includes these anomalies is acceptable. You might even love the sound, on a comparative basis.

Suddenly, for the first time you hear a speaker that simultaneously either eliminates or sharply reduces inconsistencies of transient behavior up and down the frequency range, phase incoherence, tone-stripping, etc., and it can sound "wrong" while you process a new presentation.

I was at HE2006, where 95% of the speakers used in systems had all of the problems I mention above. The dynamic behavior was shaped like an hourglass, with pinching as any sound approached the crossover points. Vocals on the vast majority of otherwise reasonably frequency-accurate speakers lacked body relative to the instrument sounds below and higher. You heard the throat and not the body, from singers. The attack and the surface composition of an instrument's notes, but not the tone. Yet many people admired the sounds they were hearing. I just watched in the Zu room. I saw many obviously very experienced audiophiles enter, sit down and listen. It was common to hear some variant of, "Whoa, something different is going on here," and then the listener would sit back and adapt to perhaps the first holistic sound presentation from a loudspeaker -- room problems aside -- in their audio career. And BTW, this happened with some industry professionals who represented other, more expensive and even very good, loudspeakers at the show. People who listened to one cut of an album or less usually didn't get it. Listeners who lingered for a few, usually did.

Look, all of us who own Zu speakers were among those whom used to accept the speaker industry's prevaling notions of quality. We owned a series of speakers that represented the best from those prevailing ideas of fidelity, within our budgets. Maybe along the way we embraced an industry maverick, like Quad ESL, planar speakers or Beveridge. And then one day, we either heard Zu or we made a decision to try it, blind. Almost all of us went through some variation of the initial experience of having to unlearn what we had been conditioned to accept, expect and tolerate from a loudspeaker in order to get music out of it.

The question this raises is, Why is a genuine advance that suggests an audiophile has been looking in the wrong places for good sound so controversial to some people who haven't even heard it, and so smoothly embraced by those who bought, many of whom are highly experienced with hifi? What's the difference between you and me?

Phil
213cobra
885 posts
 
Gregm,

Yeah, no kidding, a speaker doesn't get tested on a bench. It was an expression. Been there. Point is, it's not a legit test of what a buyer should expect if you test under conditions that don't allow the speaker to operate with all its design principles functioning. The tester must understand the operating principles of the speaker and accommodate them.

Correct about if the FRD were close to the floor. But think the Druid's dimensions are more than an aesthetic choice, instead the FRD height is dictated by the Griewe model and the rest of the package follows from there. Definition is a sealed system, so it has other factors driving its packaging, including a Zu point of view on aesthetics and space efficiency.

I wouldn't add bass modules to my Druids. I think they are better without. I am not a fan of subwoofers in general, but in the Definition they are so well integrated, I make an exception. I have two systems, so I have the luxury of maintaining the purity of the Druid in one system and using the Definitions system when I want more scale, whomp, and linear accuracy.

Certainly, I don't spend an iota of energy "defending" Zu speakers. The product and the company can take care of themselves. But helping people understand them, well....that's a different thing.

Duke,

Zu is hesitant to publish too much about their implementation of the Griewe model to the point where even customers can only get a partial explanation. I understand the competitive reasons. But your intuit of its consequences in the Druid is a pretty good stab. The way Zu has implemented the model has changed from version to version, and I don't think Zu is done developing it. Your surmise of a 37Hz lower accurate limit coincides well with both Zu's claims and the actual experience of hearing content through the speaker.

Bartok,

From a business and market perspective, no doubt Zu has a big hole in its product spread. But it has an entry product (Tones), brand-making product (Druid) that encapsulates neatly all the attributes the company wishes to project, and a statement product (Definition) that asserts the company's engineering and manufacturing prowess. I think Zu knows they have a product/price gap to fill, and whether it ends up being a dipole, a super Druid or a Junior Def I expect it will surpass Druids + Method or and have straightforward one-box packaging as well. Let them surprise us. Having built the brand-making product, lubricated the entry to Zu via Tone and made their statement, closing that gap is probably going to be the most considered speaker design project they've done to date. Patience.

Phil
213cobra
885 posts
 
Dave,

I didn't say ANYTHING about you. I made an observation. 40 years ago when I started paying attention to this hobby, the incidence or percentage of audiophiles who were well informed of the sound of live unamplified instruments was higher than today. It's an observation. I find an unprecedented incidence of audiophiles whose references are electronic, amplified or recorded music almost exclusive of significant experience with a wide range of instruments sounds unassisted by amplification.

"Less and less common..." doesn't mean "uncommon," just as "more and more" doesn't mean "most." I didn't actually say anything at all about you, and in fact said I presume that statement doesn't apply to people on this thread.

OK?

This crowd is a minority among audiophilia. We have to generalize in order to see what's happening to an ecosystem. A generalization informed by long experience does not label an individual, it simply applies to an observation of what's been happening with a group. And that group is a superset of the intensely-interested audiophiles here.

Phil
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