[ooheadsoo]

I'm sure some of you, like Joshk have read this already, but just thought to post it for those of you who have not seen it.  

Re: high or low xmax  http://zaphaudio.com/lowxmax.html

[_scotty_]

A point to consider, every octave lower in frequency  a driver reproduces requires four times the excursion of the previous octave required to be reproduced at the same SPL.  Regardless of how a speaker system or driver is designed bass reproduction at volumes similar to that of the midrange requires excursion and lots of it. In the case of a sealed system there is no upper limit to the excursion required  to adequately reproduce low bass notes.  A vented system has help from the port output at the lowest frequencies the system is designed for.  Reducing the need for driver cone travel will always reduce distortion but it is important to remember that if a driver has
2mm of linear excursion that defines the limit of low distortion travel available to the cone. If this parameter is exceeded the distortion will rise
rapidly with predictable consequences to quality of sound the driver produces. Another key reason to limit the excursion of any driver which
reproduces both low frequencies and high frequencies is to limit gross
levels of doppler distortion.  These are some of the reasons that modern loudspeaker designs have gravitated towards multi-way multi-driver designs.  
Scotty

[ton1313]

From 6moons to all of the people that have opinions without listening...

http://www.6moons.com/industryfeatures/zu2/zustuff.html

[213Cobra]

Hmmm.....once again, the most energetic critics of Zu speakers haven't heard them. As I tell entrepreneurs looking for funding, if most of the people you talk to get what you're doing at the start, you're probably not doing something important. Clearly it will take some time for a good part of the market to catch up to what Zu has done.

The benefits of break-in are expecially obvious and sometimes dramatic on full range drivers. If you owned 10 dozen 2, 3, 4 way speakers with crossovers in the 2kHz - 5kHz range, you won't likely have experienced as much benefit from driver break-in as with the Zu FRD.

Are the Soundstage measurements legitimate? No. How many times does this have to be cited? The Druid requires a floor and an air-gap between the base and the floor, and moreover, the small changes in the height of that air gap have large consequences to performance and texture of bass. On the Definition this is not an issue.

Does the speaker lobe? What doesn't? I'm not moving around much when I listen and I don't have a problem finding frequency-accurate sound in the considerable sweet spot. I can detect some mild lobing anomalies but room factors overwhelm their significance.

BTW, if you could see 3/4" excursion on the Zu FRD, you almost certainly have a serious problem elsewhere in your system. But it no doubt would hasten break-in of the FRD!

How one hears the Druid is considerably more variable room-to-room than the Definition. But irrespective of the greater susceptibility to room effects and placement, the Druid does have more tonal color than the Definition. It just happens to have less than just about anything in its price, and has more tone and transient intimacy than anything remotely close to its price, so that in toto its design advantages deliver an exceptional aural representation of the recorded performance. A Quad ESL-57 has a more accurate midrange but much less dynamic range, much more beaming, and much less bass projection. It ain't perfect either though to many people it's still the most perfect speaker ever made. An Avantgarde system sounds stone cold by comparison despite the dynamics. Any Martin-Logan fails to integrate its transient behavior compared to Druid or Definition. Sonus Faber Cremonas and Amatis sound lovely but can't ameliorate the crossover effects. No Lowther speaker is as uncolored. Nor do any of them integrate a supertweeter as seamlessly as does Zu.

It doesn't take anything special to drive Druids or Definitions, but different factors optimize each. The Druid is a 12 ohm speaker and tends to be forgiving of affordable solid state amps and yet fully reveals the music attributes of the most esoteric tube or SS amplification you can throw at it. The Definition is intolerant of all but the cleanest and most musical design. That doesn't have to mean expensive.

You can't sit close to a Definition but you can use the Druid near-field. Talk about lobing. Sit closer than 10' to a pair of Definitions and the sound will not tonally integrate. 10, 12, 14 feet back and the soundfield snaps into focus while the tonal balance smooths right out. The Druid sounds convincing from afar, but from 6' away is incomparably intimate.

Zu's own spec sheets show the Definition supertweeter rolling in on a filter at 12kHz center, 6db/octave, same as the Druid. The upper limit of the FRD is rolled off naturally. The lower end of the FRD is rolled off naturally as well at 40Hz and the sub-bass array is rolled in on a crossover. In all Zu speakers so far, the bulk of the music is heard without passing through a crossover. The value of this combined with the relative lack of tonal coloration compared to other FRD efforts, is transformative to what many listeners can tolerate thereafter, in terms of crossover presence. Important point is, in Zu you get wideband speakers in which nothing in the midrange passes through a filter on its way to your ears.

Zu changes the order of emphasis in design attributes compared to what most speaker companies believe is important. It's not that tonal accuracy is sacrificed, it's that Zu believes transient consistency, phase coherence and dynamic range to be essential to fidelity and your sense of emotional enjoyment, too.

I've had people in my home entering as skeptics and leaving as believers. I keep a poker face as I listen to them say things like, "With that MTM configuration in this room in this position they shouldn't sound good. But they do." Equally entertaining with respect to the Druid is, "I'm hearing deeper bass than I should be hearing. Are there tone controls in this system?" Answer is no.

You can make Druids or Definitions sound uninspiring. A dead amp or a harsh one cannot be made convincing. The speakers are tolerant of mainstream sources that have the ability to sound musical. But sterile sounding components will be presented for what they are. On the other hand, it is shockingly easy to insult some big-ego systems with a pair of Druids driven by an $800 Almarro amp fed by an inexpensive SACD player or Rega P3. And yet those same Druids will tell you whether a pair of monoblock amps 5 or 10 times their cost are worth the money.

Clearly, the market is still learning how to interpret Zu speakers. The Druid is difficult to measure in a standard way, and the Definition performs way above the superficial implications of its design architecture. I don't doubt some people find some head-scratching problems to solve when dropping either speaker, or Tones, into an existing system. Compared to most speakers, just the phase coherence takes some getting used to. Most systems are delicate balance of compromises, wherein everything from cables to tubes have been chosen to act as fixed parametric equalizers to tune the system to a desired behavior. Dropping a Zu speaker into a pre-established mix is a big disturbance to whatever equilibrium has been tuned.

If you like a convincing illusion of music in your home, and you have some patience for understanding the ripple effects of plunking a Zu speaker into your system, odds are you will discover the same satisfaction as the bulk of Zu owners. If you like reading graph paper...it might take some more time to get it. Some people are just going to like a different speaker for all sorts of reasons relevant and irrelevant to sound. It's a 60 day trial to be able to speak with authority on the subject. Anyone sure these speakers can't be what is claimed about them, can easily find out for themselves whether they are correct or not.

Phil

[miklorsmith]

Word, Phil!

I've got Yello's "The Eye" rolling right now.  A little scotch going but hey, it's Friday night ese!!  Yello is the old band from the 80's that had the big Ferris Bueller hit "OH YEAH" chick chicka chicka.  They were a leading techno band back in the day and shock of all shockers, they still are.  Seriously, anybody with any inclination toward the genre must pick this one up.  It's a vocal/beatirific romp with great special effects that manages to be dance-able and listenable at the same time.  Not a bad cut, either.

Point Please!  This album has tons of big bass.  Tuneful, fast bass and also the heavy hitting variety.  Strangely, it also lays out soulful, well executed vocals.  The Definitions deliver all elements of the sound precisely.  There is no strange irritation that makes the brain wonder.  Bass pitch and speed correlates exactly with the tingling highs and lightspeed midrange crackles.  All this without displacing beautiful feminine vocal delights.

I have never heard these speakers become confused in any way.  Any material, any volume.  I haven't noticed egregious behavior moving around the room and they taper like conventional speakers off-axis.  They don't sound wierd anywhere in the room.  

Caviat - I am still working on my room issue.  Moving the panels around, leaning against the walls, has cut the peak by about half.  I never notice unless searing guitars or aggressive piano are prominent.  But, nothing less than "perfection" is the standard and so the quest continues.  I'll go as far as I can acoustically and then room correction is conceivable.

What these speakers do is unmatched in my experience and they will be the last of any parts of my system to be reconsidered.  Except maybe the Modwright pre.  

[213Cobra]

At Zu's Los Angeles show in August they played a stunning Yello cut that perfectly demonstrated the overall excellence of all three speakers. Even on the little 4 watt Almarro amp, the ability to preserve detail regardless of volume or density was remarkable. I recall the band's earlier work, but hadn't listened to anything Yello for quite a long time. You citing them reminded me of how well their sound illustrates the essence of Zu.

I agree the Def exhibits very smooth response around a room but I also think the sound does not integrate closer than 10', maybe 9'. And in fact when I have encountered people who felt repelled by the sheer energy of the Definition, it was because proximity put them in the wash of the treble output apart from the rest of the tonal composition. Stepping back changed their perception much for the better. Generally I say that people who must sit closer than 10' distance, ear to baffle, are Druid or Druid + Method customers, and not the right buyer for Definitions. In a highly damped room, I think that changes. That's my observation anyway. I don't regard it as a flaw. It's a simple trade-off given the current state of materials, practical economics and design. I think Zu has more to show us as they learn about how the market assimilates, uses and feeds back reaction about their design choices. Way back in 1975, you couldn't really appreciate what the Double Advent System could do at less than about 16 feet away, either. Nor tri-amped Tympani IIIAs.

BTW, you have to get a hell of a lot further from Avantagardes to get any sense of driver integration and even then they don't really mesh. This is true for a lot of speakers. It's OK in the Zu line as it is true that the Definition is built for scale and the Druid is built for intimacy and somewhere in there is a sweet spot where both are equally adept.

Definitions unmatched? I agree, to the point of thinking that if I hear something wrong the first place to look for a problem is elsewhere.

Phil

[miklorsmith]

I took a couple of additional sets of measurements in-room and the spikes are gone.  In fact, I have a little hole around the 250hz - 1 khz range which wasn't there before.

Call me crazy, I think these are still breaking in.  Now, I have moved my acoustic panels around and that might be partially (or completely) responsible.  It's so hard to have any true reference.

I will try to get some man-time over the holidays to do some more comprehensive measurements in-room to see what's going on.  Subjectively, things have improved considerably and I might even see if I can mount a few panels on the ceiling to further damp the room from the equation.

[jackman]

I have a little hole around the 250hz - 1 khz range which wasn't there before.

Call it a hunch but I would imagine you have several very large holes and spikes throughout the frequency spectrum.  

Am I missing something?  First of all, I have never heard these speakers so I will not comment on the sound.  However, I think crossing over an 8" let alone a 10" driver to a super-tweeter at a high frequency is asking a lot of that driver.  It may be "specially made" for Zu but no driver is immune to the laws of physics.  I would imagine those big woofers/midrange drivers have really poor off-axis response causing that to beam like crazy.  

You could talk about "break-in" until the end of time and it will not change the nature of a large driver trying to play high frequencies at a low (6db?) slope.  This article (aptly named "Monitors Demistified") explains what happens when big drivers with low slopes try to play high frequencies and it ain't pretty :

http://www.soundonsound.com/sos/nov00/articles/ustandingmons.htm

Don't get me wrong, the guys at Zu seem really cool and I have happily owned their cables.  I just find it odd that the Zu site gives no measurements or technical info on the speakers at all.  Funky pictures and clever writing might sell cables but I would expect more info before dropping thousands of dollars on a pair of speakers.

The pictures on the site are cool but the Zu folks appear to have spent all of their time cooking up frilly, romantic - albiet vague descriptions of the speakers and their sound, but zero technical info on the designs, measurements, drivers, etc.  Here is an example:

There are many definable aspects of what makes for good playback fidelity but none more important than dynamic realism. In order for music and noise to sound real through recording and playback, the electronics, recording medium, environment and loudspeaker must be capable of recreating the natural dynamic range and contrast of the event.

Huh?  So if dynamic realism is the most important factor, is there a way to measure it and compare it to other speakers?  

I have a couple questions for the person who posted this nugget:

The benefits of break-in are expecially obvious and sometimes dramatic on full range drivers. If you owned 10 dozen 2, 3, 4 way speakers with crossovers in the 2kHz - 5kHz range, you won't likely have experienced as much benefit from driver break-in as with the Zu FRD.

What?  Do you have any type of scientific proof of this or are we just supposed to take your word?  

Same guy, more questions:

Are the Soundstage measurements legitimate? No. How many times does this have to be cited? The Druid requires a floor and an air-gap between the base and the floor, and moreover, the small changes in the height of that air gap have large consequences to performance and texture of bass. On the Definition this is not an issue.

OK, I'm not familiar with the Soundstage measurements but if these speakers require special measuring techniques, all the more reason for Zu to show how it's done and publish the results.  When manufacturers don't publish data, it's usually for a good reason.  Maybe measurements don't matter.  Isn't that what Bose says?  

I also didn't see anything on the website that talked about the "air gap" between the base and the floor and the "large consequences" it could have on bass performance.  Hopefully, this info is covered in the manual...along with the suggested "break-in" needed for the driver.  

I hope this isn't Zu's idea of a specification (from the website, I'm not making this stuff up) :  

They have Mike Watt power, romance of Shane MacGowen and honesty of John Lydon.

Another nugget earlier in this thread that confused me a bit:

Zu changes the order of emphasis in design attributes compared to what most speaker companies believe is important. It's not that tonal accuracy is sacrificed, it's that Zu believes transient consistency, phase coherence and dynamic range to be essential to fidelity and your sense of emotional enjoyment, too.

It's cool that Zu has taken a different approach to loudspeaker design.  However, in my opinion that makes it even more important for them to show measurements and data to back their claims.  I would never buy speakers based on manufacturer's claims or measurements but I would definitely rule speakers out because of poor measurements.  

Maybe these guys have figured out a way to break or bend the laws of physics and make passive 10", 2 way speakers sound good.  Either way, I'd love to hear them one of these days.  They may very well sound great.  What the heck, they do have the "romance of Shane MacGowen "...let's not hope their frequency response chart doesn't have as many gaps and holes as Shane MacGowen's dental x-ray!
    Alright, I love Shane MacGowan so maybe they sound good afterall.  

Shane's choppers:

http://www.shanemacgowan.com/covers/streams.jpg
 
Cheers,

Jack

PS - If your speakers are not "broken-in" after a couple hundred hours...nevermind.

[miklorsmith]

Soundstage was given directions for measuring the speakers - they fire out a vent in the base that REQUIRES a narrow-range gap to the floor to load the driver correctly.  They did not follow the directions and the measurements suffered.

I will call your musings an incorrect hunch.  My most-recent findings are as such:

+/- 3 db from 31 hz to 250 hz, except a 5 db hump at 100 hz.  Down about 6 db at 500 hz and 1 khz, and +/- 3 db from 2 khz to 8 khz.  Above that, the measurements go down considerably but I've read the RadioShark meters aren't good up there.  Subjectively, they sound pretty balanced up high, possibly a tad rolled off.  This is in-room, at the listening position, no EQ.

Regarding break-in, everyone who owns them testifies to the unbelievable degree of transformation.  Your speculations are just that.

The FRD's aren't crossed over anywhere, so your Speakers 101 manual doesn't apply.  Please review thread.

Beaming?  No.  Still.

Frankly, I'm getting sick of responding to the same baseless attacks - not even new ones!  All these "problems" have been discussed previously.  Anyone with actual interest in the speakers, pro or con, please do a search before popping off.

[jackman]

Soundstage was given directions for measuring the speakers - they fire out a vent in the base that REQUIRES a narrow-range gap to the floor to load the driver correctly.  They did not follow the directions and the measurements suffered.

I will call your musings an incorrect hunch.  My most-recent findings are as such:

+/- 3 db from 31 hz to 250 hz, except a 5 db hump at 100 hz.  Down about 6 db at 500 hz and 1 khz, and +/- 3 db from 2 khz to 8 khz.  Above that, the measurements go down considerably bu ...

Popping off?  I guess I'd be defensive if I just shelled out a load of cash for speakers without a clue as to how they measured and was trying "fix" what appears to be a design flaw by running the speakers for hundreds of hours trying to "break them in".  Your defensiveness is well deserved.

Secondly, no offense but you still didn't answer any of my questions.  I'm not saying the speakers sound good or bad, just curious why these speakers are able to flaunt the rules of physics.  They are not the first speakers to claim this ability.  I remember reading about those popular cube speakers that, when teamed with their acoustamass bass unit, were alleged (by the mfg.) to produce realistic full range sound.  Unfortunately, I found the sound to  be neither.  

The article I  referenced in my previous post mentioned what happens when large drivers try to reproduce high frequencies.  I believe this applies to your speakers, regardless of crossover.  I have yet to hear a large driver capable of playing up to 10K, let alone 12K.  There  is a very good reason you don't see many manufacturers making this  choice and probably a good reason why Zu chooses NOT to post any measurements.  I'll give you a  hint, it aint because they measure really well.    

If Soundstage was wrong or incorrectly done, where are the correct measurements from Zu?  Please don't tell me you think your Rat Shack measurements are close enough, trust me, they are not.  If you want to talk about incorrect hunches, look no further than that one.  Rat Shack spl measurements are marginally acceptable for lower frequencies but I wouldn't bet my life on them or even purchase speakers based on them.  Where is Zu's data refuting the Soundstage measurements?  

I am not picking on Zu but there are several good reasons why people who have not heard these speakers are quick to speculate.  Frilly marketing  BS and creative writing in lieu of technical info from Zu doesn't help matters.  In the end, if you are happy with your purchase, that's all that matters.   If you find you still have issues with the sound after 2000-3000 hours of "break-in"...that's another story.

Cheers,

Jack

PS - I am a huge supporter of American companies and have often complained about manufacturers who ship production overseas.  It's good  to see a company like Zu making their products in the USA.  I hope they figured out a way to make a 10" driver that can be crossed over that high and still produce realistic music without the major off-axis problems associated with speakers of this nature.  If anyone in Chicago has a pair, I'd love to hear them.  I'll even bring along the beer and order a pizza for your troubles.  Oh, and my trusty Radio Shack meter.

[mca]

I'm surprised Adam or Sean from Zu have not jumped in on this topic. They used to do some posting here, didn't they? Seems like they could provide a lot of information in helping to answer some of these questions.

[miklorsmith]

What off-axis measurements would you like to see?  15 degrees seems like a good number to me.  I'll try to do such measurements in the next week or so.  The small kids keep me from devoting all my time to such pursuits.  And, I'm trying to listen to music too.  

I don't use the measurements to tell me what I'm hearing, rather I turn to them when something doesn't seem right.  Before I treated the room, I was getting some wierd frequency anomalies.  The detractors said "HAHA YOU'RE AN IDIOT THOSE WILL NEVER WORK HAHAHAHA".

Well, a few haphazardly placed panels and I'm flat within 6 db, in-room, from 31 hz to 8 khz without EQ.  As to the evils of lobing and egregious off-axis response?  They sound pretty consistent everywhere in the room, even in the bass region which should be lumpy.  I haven't measured that one though.

Whether the meter is accurate or not, it generally follows what I hear in the room with the Stereophile test tones.

On the break-in, doesn't make much sense to me either.  But, the big spikes I was measuring before are gone and the sound overall is subjectively mellower and measures the same, so just speculating on cause.  More directly, I'm not counting on further break-in to help anything, just wondering if it's responsible for what I'm observing.

If I come across as defensive, it's because I'm weary of answering the same questions.  Bear in mind, I'm an end user, not an educated speaker-design professional.  

Zu has posted here periodically in the past.  I've e-mailed Sean fairly recently about the measurement murmurs.  I get the feeling he doesn't put much credence in them.  "Blasphemy" you cry.  I think he's working on a bit of a treatise on the subject, but I could be mistaken.  I know they've been really busy and have just moved into a new facility.  Audio boards are probably low on their priority-list.

So, capable reader, take all this for what you will.  I'll continue to pursue and describe what is actually happening in my room and you, the reader, can choose what to believe.

[jackman]

Hey, no worries, I know what it's like to be pulled in different directions.  Your time with your children and with your listening should be a much bigger priority.  My 6 month old son just threw up on my lap as I typed my last response.  Music is  playing  in the background so I'm doing two of my favorite things at once.  

Please don't spend any time measuring the speakers at 15 degrees off axis or any other angle.  I'd rather see some unsmoothed measurements from the people at Zu, if they care to share the info.  I'd also like to hear how their driver overcomes the beaming issues off axis.  While they are at it, I'd like to see some distortion data.  That driver is working awfully hard to cover such a wide frequency band.  I'd be curious to see how that affects the distortion of this design.  

Zu may say that measurement don't mean anything, and these speakers may sound great.  There are several people who really like the sound, and they look really cool.  However, because of the relatively unique design which requres the large woofer to cover a very high freq range, I believe measurements are very useful if not essential.  Zu's website has done little to enlighten curious people and potential customer as to how they overcame seemingly difficult or even impossible design issues.

Fanciful writing and marketing-speak shrouded in mystery may be an effective way to sell cables or sunglasses (ever read the Oakley site)  but I expect more when it comes to speakers.  Who knows, I'm probably just nuts.  Been called worse!

Cheers,

Jack

[J North]

@Jackman
>I'd also like to hear how their driver overcomes the beaming issues off axis.


I don't pretend to know everything, and never have heard the Druids, but doesn't the whizzer cone and phase plug in effect mitigate the beaming issues and approximate a coaxial speaker?

[ooheadsoo]

Afaik, the whizzer cone increases and incites beaming.  It is used to extend frequency response on axis but causes increased fall off off axis.

[J North]

Not saying you are wrong, but a GOOGLE SEARCH says:

"A small second inner cone used on some fullrange speaker sto extend the high requrncy range and to give wider diepsersion oat high frequecies."

"An integral whizzer cone provides high frequency energy dispersion."

"the smaller inner cone decouples from the outer section, resulting in increased treble output and dispersion because of the increase in stiffness and reduced size."

"Lowther-based speakers, uses a whizzer cone for high frequency dispersion"

"Whizzer cone for wide dispersion and improved frequency response"

"The “whizzer” cone is fixed to the larger cone and driven by the same voice coil, but allows the overall response to reach higher frequencies with wider dispersion."

"By being light and stiff, the whizzer does not greatly affect the working of the main cone, the flexural wave traveling out from the voice coil pretty much unattenuated. This means that the high frequency can now be radiated over a much larger area, and hence the response is extended. The front of the whizzer does not horn load the centre, although the shape will affect high frequency dispersion."

[ooheadsoo]

Well...though I can find no technical explanations, it appears that the marketing speak says that you're right, fwiw, though I have commonly read of the whizzer causing beaming, which I would think implies poor dispersion.  And there is the resonant peak, which could be another cause for the beaming impression.  And I find it hard to believe that it is a free lunch outside of that diffraction(?) peak and dip.

[213Cobra]

Jackman,

You cited a couple of quotes from my earlier posts:

PHIL: "The benefits of break-in are expecially obvious and sometimes dramatic on full range drivers. If you owned 10 dozen 2, 3, 4 way speakers with crossovers in the 2kHz - 5kHz range, you won't likely have experienced as much benefit from driver break-in as with the Zu FRD."

JACK: "What? Do you have any type of scientific proof of this or are we just supposed to take your word?"

I haven't even investigated "scientific proof". The effect is plainly evident. I have heard subwoofer break-in have a dramatic effect. But for most multi-way speakers, the crossover is such a grossly compromising ingredient as to overwhelm break-in effects for much more narrowband drivers, especially those that use synthetic or metal cones with soft surrounds. I am sure my observation can be proven through objective measurement, but life is too short to bother and I don't have the time. I am the consumer, not the maker. The break-in phenomenon is real, and virtually everyone who lives with Zu speakers -- even those who have never met each other -- independently comes to the very same conclusion.

JACK: "Same guy, more questions:" (Yes, that's me)

PHIL: "Are the Soundstage measurements legitimate? No. How many times does this have to be cited? The Druid requires a floor and an air-gap between the base and the floor, and moreover, the small changes in the height of that air gap have large consequences to performance and texture of bass. On the Definition this is not an issue."

Soundstage uses an unvarying test method for measuring speakers. According to Zu, the magazine was educated about the placement requirement for the Griewe model Druid (on the floor, with the air gap). The magazine apparently refused to yield and measured the speaker suspended mid-air, per their practice. The result is a frequency curve for a speaker used improperly and not even close to being reflective of how it will sound properly placed and adjusted. It's useless as review data in practical terms other than showing you how a Druid Mk II will perform when suspended in thin air, perhaps hung from your ceiling as a 49" high cavity for your stash.

Look, it's clear the Zu web site has incomplete information relative to what you're asking for. That said, the gross acoustic effects of anyone's domestic living environment overwhelm anechoic chamber results. There have been scads of speakers produced over the years that graphed well and sounded like beetles eating bone marrow from a dead cow. It's really only worth so much. Worth something. But put it in your room and the room rules. We only know how speakers sound relative to each other in the spaces we hear them.

However, you pose a legit question: Does Zu's FRD beam? Well, it has a narrower projection field than, say, a Bang & Olufsen Beolab 5, and a broader one than a Quad ESL-57. How's that? At 8', the sweet spot for a pair of Druids is about 3 bodies wide, with enjoyable music being dispersed over a much wider area. With Definitions, the FRD-T-FRD configuration limits vertical dispersion and improves horizontal spray. Zu says the Def is flat across about 30 degrees of spray. It sounds better than that in practice, and does really well as the mainstay for a 2 channel home theater as well as music. With some judicious toe-in, all the Zu speakers beam too little for this to be a practical concern in domestic rooms.

Whizzers are intended in part to improve high frequency dispersion of full-range drivers. As someone else pointed out, a little drilling via Google substantiates this, plus it's a mainstay of car audio for the same reason, among others. I've owned narrowcast speakers (Quad ESL57), selective narrocast speakers (supertweeter on Dahlquist DQ10) and near-pointsources with lots of spray (various small monitors, LS3/5a, S3/5, SL600, SL700, etc.). The Zu FRD is entirely usable. In the Druid and Tone, dispersion is more than adequate to be removed from inhibiting a decision to buy. In the Definition, dispersion is willfully engineered to be broader by design.

Again, you really have to hear them to judge. Speculation in the absence of audition only deprives you of a superb experience that will challenge what you think you know about audio and getting good sound in your home.

Oh...and when not broken in, the FRD does beam perceptibly, and it does "shout" some. These effects are ameliorated rapidly in the first 60 - 80 hours of use.

Phil

[J North]

Well...though I can find no technical explanations, it appears that the marketing speak says that you're right. . .

actually, most of the quotes are from faqs from audio information sites.

[_scotty_]

The effects of a whizzer cone are fairly easy to demonstrate.
Construct a megaphone out of light cardboard. Have a friend stand in front of you while you speak and start walking away at a right angle and have him note how much the loudness of your voice decreases as he walks further off axis.  The directional nature of the whizzer cone on the higher frequency portion that the driver is supposed to reproduce explains why you are supposed to listen to Zu loudspeakers directly on axis.  ooheadsoo is 100%
correct in his statement.  

Afaik, the whizzer cone increases and incites beaming. It is used to extend frequency response on axis but causes increased fall off off axis.

 
Scotty