[miklorsmith]

My Fostex 206E's, which are 8" drivers, beam Much more demonstrably than the Druids or Def's which have 10" drivers.

[213Cobra]

Uh...not exactly, Scotty. A megaphone itself is not the same as the megaphone-like appearance of a whizzer in the context of residing concentrically within a larger cone. More to the point, the whizzer itself isn't the primary transducer  nor is the acoustic energy coming from a source inside the whizzer "megaphone".

Lots of smaller speakers beam more than the 10+ inch Zu FRD. There's no substitute for hearing the absence of beaming that would be pertinent to domestic stereo if it actually existed.

Phil

[Russell Dawkins]

Scotty,
this flies in the face of all of J North's quotes (posted at 8:25pm) and I think the reason is what your paper megaphone experiment demonstrates is the effect of a horn, and a conical one at that. This might be valid if the sound source were within the throat of the whizzer, but you'll notice there is a phase plug there on the Zu FRD.
In the case of the whizzer, the source is the whizzer cone itself, which is smaller than the main cone and thus has intrinsically wider dispersion.
Russell

[_scotty_]

This kind of makes us fall back on how the response curve looks on the speaker above the wavelength that is equal to the 10 inch emissive diameter
of the driver.  If we examine the much maligned graph from SoundStage it appears that for what ever reason the whizzer cone is only partially effective
at ameliorating the expected rolloff off axis that would occur
above the frequency approximately equal to the 10inch emissive diameter of the driver.
The whizzer cone is not equivalent to having another driver dedicated to reproducing the midrange in pistonic behavior or moving mass.
Anyway you look at it the whizzer cone is an imperfect solution dictated by the desire to have the driver cover as wide a range as possible.
Scotty

[gonefishin]

I haven't heard the ZU speaker...but

    ...this thing is essentially a single driver (full-ish) range driver with a "super" tweeter above 10k or so...right?


    I wouldn't be expecting a miracle in frequency response or anything...from any single driver speaker.  But despite the way some single driver speakers achieve the frequency response...some sound pretty good.  But I wouldn't give it too much criticism...but I wouldn't expect it to do things it couldn't either.

     Some single driver speakers sound like fart boxes and some sound rather nice.

[GHM]

I agree single drivers or wide range drivers have their short comings. At the same time mulit drivers with 10 pounds of cross-overs in the signal path have more short comings as a whole. Being phase and impedance problems,cross-over distortions,driver and timbre matching. And a host of other things like wiring drivers out of phase to get a better phase and time alignment which doesn't work well in all cases.

The one thing a single driver does that no multi driver speaker can do, is speak in one voice not 3, 4 or 5 voices as some multi ways perform. I've heard more multi way acoustic bass reflex speakers sound like fart boxes than I can shake a stick at.
So pick your poison. I'll take the phase and time aligned speaker with minimal crossover parts and less distortion any day. In the end there's no free lunch for anyone!

[DIAR]

Disclaimer: I'm not 100 % sure about this:

Do you guys know that Druid driver is based on eminence B102:
http://editweb.iglou.com/eminence/eminence/pages/products02/legend/legb102.htm

According to manufacturer the efficiency is 95 dB. Zu claims 101 dB  

Tweeter is probably based on this:
http://editweb.iglou.com/eminence/eminence/pages/products02/hf/apt.htm

B102 costs about 100 euros and APT:80 about 30 euros.

I'm waiting for my Druid pair. I will hopefully get them next week. I will probably try to clone them just for fun.  

[Gridlock]

Disclaimer: I'm not 100 % sure about this:

Do you guys know that Druid driver is based on eminence B102:
http://editweb.iglou.com/eminence/eminence/pages/products02/legend/legb102.htm

According to manufacturer the efficiency is 95 dB. Zu claims 101 dB  

Tweeter is probably based on this:
http://editweb.iglou.com/eminence/eminence/pages/products02/hf/apt.htm

B102 costs about 100 euros and APT:80 about 30 euros.

I'm waiting for my Druid pair. I will hopefully get them next week. I will probably try to clone them just for fun.  

I checked the link and there is no effeciency rating listed for the driver.  SPL (Sound Pressure Level) is listed at 95db, which is not the same thing as effeciency.  SPL is the maximum 'loudness' level that the speaker cone can achieve.  I'm curious where you got the information that the Druid is based on these drivers?  The main driver (in the Zu Tone) does look similar, but that doesn't mean anything.

[DIAR]

SPL is the maximum 'loudness' level that the speaker cone can achieve.

What ??

As I mentioned, I can't be sure about the things I stated. I have read about this from unreliable sources. It's always like that in the internet.

According to soundstage the efficiency is 97 dB (300-3 kHz). Zu has given the peak value (@2 kHz).

I'm quite convinced that the driver is based on B102. There is ofcoure the phase plug.

I have simulated the enclosure with Martin King's mathcad models. The results match the sound and Soundstage measurement (Soundstage measurements haven't been made properly because of the unique bass reflex vent).

Compare these two measurements:

Eminence B102


Zu Druid:


The tweeter issue is different. Obviously the tweeter is based on eminence tweeter. The tweeter and the "horn" that Zu uses are made of different aluminium or the aluminium has just been polished. I believe that the horn is a bit different. Who knows what else is different. Possibly nothing.

http://www.6moons.com/audioreviews/zu/2strip3.jpg

http://editweb.iglou.com/eminence/eminence/pages/products02/hf/apt.htm

http://www.partsexpress.com/images/290-530m.jpg


One more time. These are not facts. Just some thoughts that I find quite interesting.

I think Zu Druid is simply awesome speaker. It doesn't measure well but it plays music better than any high end speaker I have heard.