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.


WOW! opened my eyes...
Feel better now?
And what the hell is a ZU loudspeaker.. anyway?
Great post. It's been awhile since a good thread worth monitoring.

BTW, it's a lot, not alot.
In the NY Times this morning was an article about Netflix, and it contained this quote from Reed Hastings, the Netflix CEO:

"At the heart of any good investment, I tell investors, is a contrarian thesis that they and the company believe very deeply," Mr. Hastings said, "and that the rest of the world thinks is crazy."

Thank goodness there are people like Sean from Zu, and all the other small audio manufacturers swimming against the tide. This hobby of ours would be incredibly boring without them.

By the way the ying and yang theory apply here, Always gonna be the people with the opposite reaction, or simply want to slow something down or hurt it... You bring something new or advanced in a way nobody else has done exactly or conventionaly at least, just as Klipsch, or Avantgarde, you will have to expect some backlash.. Zu was just not concerned with this aspect cause they cared more about the product, but this knocked on their front door, and now they realize they need to prepare… Everyone will shot for the top guy its just in the nature of this.
Thanks Sean,

Don't react too much to the naysayers and keep your energies focused on your family and your company. Your customers will not be swayed and those curious and open minded enough will take you up on the in home trial.

I appreciate the fresh approach you guys are taking and your products are beyond excellent value, I am enjoying my system and my music like never before. Some of the folks on this website have nothing better to do but to try and pull others down so please don't take it personally, easy to say and hard to do. Keep developing new ways of thinking into products and the rest will take care of itself.

Everyone will shot for the top guy its just in the nature of this.
Undertow (System | Threads | Answers)
Some of the folks on this website have nothing better to do but to try and pull others down so please don't take it personally, easy to say and hard to do.
Ghasley (Threads | Answers)
I have written time and time again of my respect for the Zu Audio team, and the company they are building. It's excellent for high end audio, and especially for American high end audio.

I hope people will realize that one's discussion of preferences in loudspeaker sound, and particularly as the preference may lie with brands other than Zu Audio at the present time, does not have anything to do with shooting for the top guy, or with pulling others down. It's merely an expression of opinion which contributes to healthy and complete discussion. At least that's my intention.

I certainly did not intend to imply that you were trying to pull Zu down if that is what you took from my post. I was meely trying to say that some who have never heard the speakers act as if they have, which is dishonest. Second, those who try to discredit fact, that is that Zu's FRD is somehow adversely affected by a "phantom crossover" are trying to discredit Zu in a dinhonest way.

If people have heard the Zu speakers and find another loudspeaker more appropriate for their system, that's cool. I think that is one thing we can all agree on. I am unconditionally a 2 channel guy and I get a great deal of satisfaction from it. I enjoy the Zu speakers and the Druid and the Tone are real world priced and EXTREME values.

Sean, Adam and the rest of the Zu team should not get distracted by these posts but should merely peruse them periodically for useful input. Highly likely that they will not discover much useful out here but you never know.

TVAD, your posts are always logical, kind and I have no beef with you or anyone else...except maybe the surround sound guy with 3 systems. Seems somebody has alot of money and is used to everyone believing he is always right...or maybe he doesn't have 3 systems after all. One of the pictures I saw of his system posted here had a "really nice refrigerator" in the background...probably the same electrical circuit as the system would be my guess but it's irrelevant.

Sean, BRAVO!--the cream always comes to the top....

I appreciate your post, and I think your cables are great. I hope to hear the speakers sometime.
Why is the Zu driver referred to as a full range driver (FRD)? While it's an impressive piece of engineering, It doesn't cover what is traditionally considered the full audio range, namely 20-20k Hz.

As I interpreted the thread the negativity expressed wasn't directed against Zu (1 poster excepted), but was instead directed at the zealous nature and borderline cultish attitude of Zu's advocates. It's one thing to have people say they prefer one product over another, but a line gets crossed when those same people vociferously and repeatedly say every other product is wrong and then try to back up their preferences with rehashed semi-techno babble. Should anybody really be surprised that other people might challenge such assertions?

And as far as product bashing goes, this thread was nothing. Search the forum archives for threads on DK Design amps, or better yet Gilmore speakers. Now there was serious product knocking.
Well like Zu says he's willing to work with us to get his speaker in our home for a test listen. I'd be willing to pay half shipping costs, Zu pays ship one way, I pay ship back. I'd give them a fair review next to my comparable Thor, comparable price/size,weight/dynamics. I feel my system's components offer a relatively fair enviornment. As you know I believe the Seas' drivers to be THE standard by which all others are judged.
btw ZU, lets use FedX, as UPS is a joke.
If the Druid's were over 100 lbs I wouldn't bother in asking, as I don't fool with speakers over 125 lbs. Weight/sound/price, all 3 are very important factors when deciding on a speaker. I would never buy a speaker over 150 lbs. Zu keeps his top of line Definition at 125. BRAVO to Zu for that.
Which makes for my next topic. over weight speakers. Now you know the Wilson's are gonna get slammed, yet again. hehe
>>lets use FedX, as UPS is a joke<<

I'd be careful with that.

When shipping air, I prefer FedEx. However, UPS is the better ground carrier as every person touching the package is a UPS employee. FedEx contracts many of their ground shipments to independent carriers and you never really know how the package is handled and who is handling it.
Onhwy61, 20-20k is your description of a full range audio spectrum, not a full range driver, meaning the limits of the driver themselve is full range without filter, So no its not 20-20 but that means that fostex or Lowther never did it either, so then a Full range driver does not exist in your opinion period, not just Zu's. Thats fine. I could be wrong but it seems we are nit picking a very fine line on marketing here, not what matters in audio.

Also, the topic had to do with Crossover or not, so although I guess this FRD discussion applies here to an extent thats not what was disputed.

Third, I really did not want to make second post on this thread in order to keep it clean, but since some want to bring it on the table we have to argue it a little again.
Are there any published measurements on these speakers?

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.

I sent a cdp to califorinia and it was bubbled wrap with 2 layers in a single box, arrived trashed. partly my fault for not double boxing. Now its 6 months and am still waiting on my $500 ck. Katrina has claims backed up for at least 1 yr. This is why I suggest Fedx. Fedx is more careful also.
I agree on FED EX, and it seems the only way Zu ships is Fed ex anyway from my dealings with them, so don't worry.
I'm not a Zu owner or even potential customer since I already have large fullrange/wideband, hi-efficiency, speakers that I am very happy with. But, I finely got to hear Zu's Definitions under halfway decent conditions at HE2006 and have to say they impressed the hell out of my (even allowing for room interferences).

Not to mention that Sean and Adam, once again, proved to be great guys to hang out with. No smooth sales pitch or "hard sell". Hell, they weren't even trying to "soft sell" their products - just putting music on and letting it play.

And I have to admit, that after meeting these guys twice and listening to their products, that if I were in the market for hi-eff speakers - theirs would be at or near the top of my list. Especially, the Definitons. I use dual passive subwoofers and that simply wouldn't be necessary with the Defs.

More power to the Zu guys and let's hope they can't get some white papers out to satisfy the curious and critics.
Hi Sean,

You've cleared up some of my misconceptions about your 10" driver. Very, very impressive linear x-max capability for such a high efficiency, wideband driver. Yes, I'm jealous.

On the crossover terminology issue, note that different writers have used the term "crossover" in slightly different ways depending on the context. Perhaps to be exact we should use the terms electrical crossover, mechanical crossover, acoustic crossover, and maybe even electro-mechano-acoustic crossover. But that's just too unwieldy.

I build a speaker using a Fostex augmented by a supertweet on top, and refer to the passing of the signal from one to the other as a "crossover", even though there is no electrical low-pass filter on the Fostex (other than the inductance of its own voice coil). Maybe I'm misusing the term, I dunno. But I bet that unless I built a speaker that people were seriously taking notice of, no one would give a rat's ash how I used the term.

I enjoyed your post. Thanks for taking the time. For someone whose brain process is panoramic rather than linear, you did a fine job of communicating with us luddites.

"Physics". There, I said it! Now they MUST take me seriously!


Mechanical Engineering Dropout, 1978-1979
I use FedEx and UPS daily to ship hundreds of packages every year. I'm sorry you had a bad experience with one of your UPS shipments but you're flat out wrong in your characterization of FedEx being a better ground carrier. UPS is clearly superior.
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.

Spoken like a true Physics major dropout! Your endless ramblings laced with words like "pissed" are not going to get people to audition your speakers. I hope you realize that there are some of us on here who have technical backgrounds and have an advanced understanding of physics. I am sure you make a decent speaker but I wish your zuids would not go about it like it was the best thing since sliced bread.
You want to know what I think? :)
I've never heard Zu speakers or cables before. A few months ago I was in the market to spend my hard earned $3000 on new speakers. Audioned many speakers locally in Phoenix and loved the Spendor S8e speakers the best. Well, the new Domus Sonus Faber Homes were probably better but cost $5k.

I considered the Zu speakers and read all the threads and reviews available. Visited the Zu Website but didn't find enough concrete information on them. Not enough to justify buying them. The website is seriously lacking in information on speakers and the cables. The only information I found that helped was that these speakers would not perform 100% in my overly large 25x30' w/ 10" ceilings room.

As I see it, this is the reason for alot of the gossip on the forums. If there isn't enough information available people will question and gossip to find out more. I've been interested in teh Zu speaker cables but I cannot find any information anywhere what these cables are made of. Well, sorry to say there is no way I can choose them over others. I'm too carefull of a buyer. What speakers did I end up buying? The Usher CP-6371. I love em. Sound great in my room right now. I kinda wanted those Spendors but coudln't swing the money. I think these Ushers are filling this room more than those Spendors could anyway.

Sean, it's great you got onto a forum and addressed poeples questions. Alot of good manufacturers do. But, as you mentioned, your not really computer friendly. Or rather, forum chat friendly. Since that the case I would strongly suggest maybe someone you know and trust do it for you. They can put Zu on with a happy face and cheerfully, positively answer questions. Problem solved.
BTW, I'm taking time out of my day to post on here too. We do so because its our love and hobby. we do it out of interest in products and manufacturers do so to support existing and broaden their client base. Alot of manufacturers like "Bottlehead" have their own forums on AudioAsylum and CircleAudio. Just a thought.

Hey, we like that your a real flesh and blood guy. A joy to converse with on many subjects I'm sure. :)
After 168 posts about Zu Druids bass response, I still have 3 doubts:



IS THERE ANY FULL RANGE DRIVER (MARS INCLUDED) REACHING 20-20K HZ? (heck, I can´t even hear higher than 17k and my room can hardly support 30 hz)

Thanks in advance ....
If the sound and performance of the product is not enough to qualify it in your mind then you would be better served by a company which specializes in white papers and measurements. One of the things that has impressed me about Zu from the outset is its willingness to provide actual experience rather than dazzling me with technobabble.
I personally believe that Zu exceeds sliced bread in at least four different and important ways and I am preparing a thesis on that very topic to be published in late September. If you would like I can notify you of availibility at that time.
Meanwhile, you should not assume that Zu makes a decent speaker but rather try a pair at home and learn that they make an excellent speaker. Or that they don't. Right now you lack data.
I think you're right about there not being much info on the Zu website. The way I dealt with that was to call Zu and ask questions. It so happened that Sean answered the phone. I found instant rapport with him and now count him as a friend. Since I'm within driving distance, I travelled to Ogden to hear for myself but, if I were farther away, I would have taken them up on their money back trial offer. They've shipped everything FedEx ground that I have received so far and the one way shipping charge for both my Druids was only $40. If anyone out there is considering this option, give Zu a call and they will give you a firm quote on one way shipping. These guys do not mess around with service at all. They are loose as hell in their personal interaction but the business end is as professional as anything you will ever encounter.
Speaking of Zu......
This might be of interest to some of you......

Some guy on audio aslyum made a short comment on the Zu's he heard on SEVERAL systems. Thats fair to me. You can read it there.
FAQ: section at Zu looks like it is now building some info, not sure if its new but here it is for someone that is interested..

Stylinlp_38: I traded out of Usher 8871 into Zu Druid last year. The 8871 is at a considerably higher price point in the Usher lineup than the 6371.

It took me several weeks to understand the Zu sound, but once I did, it was very similar to what Phil has indicated; that I could not bear to listen to the Ushers (I'm pretty sure that means all conventional speakers, but those were the ones I had on hand) after that. I even tried putting them back in for an intended period of three days; they lasted perhaps 24 hours before I started squirmin' and yearnin' for the Druid sound.

That said, Usher makes an attractive speaker and is quite respectable sonically in its price range, and if you compare them with other conventional speakers and assign value to the looks and cabinetry then they are a good value. I was reasonably happy with them for two years before I moved on, although I did spend a lot of time looking for the right amplification without success.
Macrojack: Speaking of Zu......This might be of interest to some of you......

Interesting read. Excerpts from Sean: "We thought we would have no problem pulling 500+ locals...and force HiFi to come to terms with the whole DJ culture stuff...But in the end, it was a bust. Only about 50 locals hit the show...The music rushed over the fifty of us who remained, bass pounded our mind, body...There is nothing so cool as super loud, super clean awesome music that is played with an into-it crowd...[Next time] We might have to bring along a bus load of hot ladies from Utah to jump-start the thing...The market is massive - outside HiFi...."

The last comment caught my attention, don't know how to read it.

Zu definitely has a unique personality. I can't imagine Harbeth or Tyler attempting this! I am sorry the party didn't work out, wish it had. I can see why Srajan feels bad. The airport location had to discourage the locals.

I am a classical person, not quite into super loud DJ scene. But if they ever organize a classical event around Chicago, I will show up.
From all these posts, it looks like shipping info is very important to Zu owners. If someone can point me to a review
or website with some measuremnts which confirm their performance, I'd appreciate it. Mahalo.
Thanks to Sean for taking the time to post. Clearly his words were a direct wire from his brain - no crossover! Sort of reads like 'Trout Fishing In America' ;).

A couple of comments on the other posts in this thread. Firstly, I don't think it is reasonable to expect Zu to pay the cost of shipping their speakers to your home for a trial with you paying the costs of shipping them back if you don't like them. I mean get real. Secondly, the "Physics dropout" slag is just plain BS. Who the hell cares? If you have a beef with the physics, then say so, but when you get catty about credentials, all I see is a green-eyed monster, and no it doesn't make you look credible.
I just mentioned that the Zu's were reviewed on audio asylum, short, one sentence, but to the point. Have a look.
The reason for discussion about shipping info is Zu's money back guarantee. If you buy a pair and elect not to keep them, then you will be responsible for return freight. Therefore, shipping info determines the amount of risk involved since there is no restocking fee.
I don't know of a source for independant measurement. Perhaps that sort of thing is meaningful but not to me. I think that actually tasting the food will be more revealing than reading the recipe.
Your post hints that you might be in Hawaii and I can imagine that the shipping risk is a good bit higher to your island than what we face on the mainland. Perhaps, by contacting Zu you can find out if anyone in your area has a pair you can audition. Zu owners are usually pretty open to sharing.
I would have liked to see what the setup sounded like but I'm sure I couldn't handle more than 5 or 10 minutes of it myself. A high percentage of us audiophiles are refugees from a time past and I speak for myself when I say that. Zu wants to engage younger people and perhaps bridge the generational gap that threatens to kill this industry along with the diminishing number of us dinosaurs who presently support it. I too applaud their effort.
The only credibility problem I had with the piece concerned the "busload of hot ladies from Utah". Utah? Hot ladies? Huh?
Isn't the Zu best setup with a low watt/single ended tube amp? How many of us are interested in low watt tube? So this speaker is geared toward a specific customer. Sure its not limited to single ended, but its IDEAL for low watt tube.
>>Sure its not limited to single ended, but its IDEAL for low watt tube.<<

Absolutely untrue. I've run the Definitions with a number of tube amps, including a pair of Art Audio PX-25 monoblocks (6WPC), but my personal favorite is a pair of Pass XA-60 (60WPC Class A) amplifiers. If you haven't heard them with different amplifiers, don't make assumptions.
Bartokfan, absolutly not.... look at my system. By the way they recommend McCormack DNA500, Mcintosh, and Nuforce solid states with these speakers.
Bartokfan, Yes of course you can use tube though, just mentioned the fact SS is perfectly fine with them.
No! The Zu speakers are not best set up with any specific amplifier type however your choice of amplifier will play heavily with the results you achieve. Hence, amplifier selection affords an excellent opportunity to manipulate the results to suit yourself.
I can't answer your question concerning how many of us are interested in low watt tube amps but I think my comments above address the significance of that query.
I have Zu Druids and I felt that the ASL Orchid I used and still have was underpowered at 3.2 watts per channel. It sounded very nice but wouldn't "up and boogie" with the Druids the way my other amps do. I get very nice results with an Onix SP-3 at 38 watts and a Pass Aleph 30 at 30 watts. Zu ran 400 watts into the Druids at their recent RAVE party in L.A. So I think that kills your notion that there is any ideal type of amplification or amplifier power rating for Zu speakers. They are much more versatile than most and certainly not limited in their appeal to anyone with sufficient curiosity to explore their possibilities.
The way your post was worded, I'm not sure if you were asking or telling but in either event you were misinformed.
I've had my speakers for about 6 months at this point and have explored their capabilities fairly comprehensively. One area where I have not pursued their limits is in the area of SPL capability. It does not take much input to make them play very loud. They certainly will exceed my upper threshold without breaking up at all. You would never guess to look at them that they perform as large as they do.
On the other hand, however, they have a very complete sound at low listening levels. All the speakers I've ever owned in the past needed to be brought to life at a certain decibel level and these do not. Their delivery is well balanced and easy and natural from a whisper to ear bleed pressure.
I'm providing a comprehensive answer here because there appear to be a lot of misconceptions about Zu. There is nothing complicated, difficult or specialized about them. They are speakers, just like yours are. The difference lies in how they do what they do. And this must be experienced to be understood. Please do yourself a favor and find out about them for yourself. This rumor mill is potentially damaging to a small, innovative and sincere company. All I'm asking is that you know whereof you speak before contributing to the confusion with unfounded speculation and imaginary shortcomings. Thanks.


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.


I suggest you read the 6moons article as linked in Aktchi's post above. Perhaps the Zu's "ideal" match is something other than an SET amp....

For all the Zu owners here: what's the most power you've run through your Zus in your home, and what were the results?
I have only ever used my Definitions and Druids with solid state equipnent, with excellent results.
PatD on audio aslyum provides a link to the Druids measurment graphs. I can't interpret graphs. But take his word for what he sees..
We've been running the Zu Druids for about a year or so now. I have some comments about the speaker if y'all are interested:

First, the speaker really is efficient. The impedance is easy for our small amp, the S-30, which can play it so loud that we can easily simulate a band playing in a real club. So there is no issue with dynamic contrast or dynamic range in general. We've not found the upper limit of the speaker yet :)

Except for the bottom 2 octaves the speaker is quite uncolored. There is a slight amount of 'box boom' in the 2nd octave and there is not much of the bottom octave below about 35 Hz. We've found that tone controls do help a bit in that regard but mess everything else up. Otherwise the speaker is very neutral and detailed. If your music source is smooth, so is it, if brash, so it is. It is also quite revealing- nothing slips by it.

Overall the speaker is an excellent product. It solves so many speaker issues all at once- size, bandwidth, efficiency, impedance are all good. You only miss the very bottom octave and you totally get everything else.

I'm thinking real seriously about using them for PA. Imagine a PA that doesn't sound like a PA- and these speakers are small and light at the same time. They really are a very nice advance.

So- do we like them? Sure we do- we bought 'em! We also run Classic Audio Reproductions and are fans of MG-20.1s, Wilsons, Sound Labs and a host of others. Most of them won't fit in the shop though and the Druids do it with ease!
The audioasylum discussion lead me to this source of measurements on the Druids:


The impedance curve indicates the Zu won't be a good match with my amps, but it explains why they work so well with
SE tubes amps and have lots of loyal fans.
It took me several weeks to understand the Zu sound, but once I did...
kck, can you elaborate on that a bit? Just for the sake of stimulating discussion, let me put this question on the table: If the Zu's sound like music, if they sound "right", why would it take several weeks to "understand" their sound?
Bartokfan, PatD on AA? What is the verdict they measure good or bad, in his opinion... I am just curious as we seem to be running in circles with this, and I have no idea how to find or read what you are, or if you are saying no way you will even deal with Zu, or you are very eager to hear Zu? Please just state what you are getting at, thank you.
Drubin, as in most things it takes experience to learn something. Wine, music, food. As one grows, matures and experiences these things regularly they learn to taste, see, smell, hear subtle differances. People that are really into SET amps and high efficiency speakers have been around for years. Very experienced in 2 channel stereo.

As I see it, I'm definately a noobie. Only been serious into high end sound for 5 years. Just one of the unwashed masses until I found the AudioAsylum back on 2000.

The response Kck gave me earlier I fully understand. He's moved on beyond my experience. I can tell that hes right. One day I will outgrow these speaks and most likely move to Setamps and high eff speakers. I kinda wanted to this time but I dont have a tube amp plus my room doubles for home theater. That helped my decision on picking the Ushers. Hes right on the reason why I choose them. The thing is my last pair of speakers are only 1995 Mirage 490i tower speakers. So to me, these ushers sound fantastic lol.
Atmasphere -
Thanks, Ralph. It really helps to have input from someone with your credibility. The rest of us have had the same experience and results with Zu but for reasons unknown we fail to penetrate the skepticism of some readers. Maybe they'll listen to you.