I think that the report speaks for itself. It goes on about how well the CBT controls the vertical directivity but then a small section shows the horizontal data. On a 10 dB per division scale it looks like the horizontal response fluctuates about 10 dB. That's not really much control at all. The vertical is pristine - exactly what I try and achieve horizontally.
Well having heard them twice, I'm not so sure. I listened carefully and did a lot of walking around them, near and far, low and high. The horizontal directivity seemed smoothly tapered from near omni to tight, bottom to top. I've never heard anything else quite like it.
I don't know if that qualifies as "controlled", but it's not random.
I don't know if that qualifies as "controlled", but it's not random.
Let's see now what speakers have great dynamic range, identicle h and d dispersion, a flat fr and are a point source over their entire range. Well its not my DSP laden EVPV-Scala's because they are two way and therefore have vertical nulls. Which brings us to diffraction. IMO it is the fr of horns that is the biggest issue, most of which can be corrected with DSP. I feel like diffraction may be less of an issue than the other issues and if controlled, may well be the best trade off we can make. Sounds sort of Synergistic to me, we will see (-:
The DH1A has a HF peak around 13.5 kHz, 20 kHz is about 12 db down from the 10kHz response.
I EQ them (actually DH1AMT, which is the DH1 with the 1.4 to 2" snout adapter removed) flat from 800 to 16 kHz in my PA.
When using a crossover below around 1200 Hz, the effortless midrange of the 3" diaphragm more than makes up for it being a little rough above 13.5K, at least for me, but I can't hear above 16 K, so there is less than 1/3 octave of rough response anyway..
Using a driver like the DH1AMT makes building a Synergy quite easy, as it can cross directly to 8" (or even 10") speakers which can make it down to 60-100 Hz, where subs can take over.
The screen shot below is a BMS 4550 1" exit driver compared to the EVDH1A, both on the same horn.
Recordings of a variety of different drivers at various levels and crossover points are here:
http://www.diyaudio.com/forums/multi-way/212240-high-frequency-compression-driver-evaluation.html
You can hear how the small diaphragm (2" or less) drivers sound distressed at levels some 6 dB less than the 3" diaphragms, even with a 1200 Hz 24 dB per octave crossover.
Art
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I've posted independent 3D polars of a CBT several times and they look great horizontally. Not perfect, but very little lobing and amazingly uniform. Geddes has seen it.
The measurements of CBT36 vs. B&W Matrix were conducted in a store house with uneven floor and smoothing is only 1/12. Like I've indicated before; Don may have done wrong in posting these. People either misinterpret them comparing them with data with much more smoothing and done under better conditions.
Turning the CBT the other way would completely defeat it's purpose. If you wan't a narrow horizontal dispersion, buy a horn. The CBT is for a different purpose. Avoid vertical reflections and have a broad horizontal bandwidth. The advantage is obvious; It can cover a large audience and in a home environment it can yield a spacious soundfield if that's desired. If a precise image is wanted, one needs two (or 1 and half to be accurate) absorbents on each sidewall. No vertical treament is necessary.
@peteleoni
The B&W Matrix speakers have a pretty poor power response. The fact that they have been popular in studios or that Keele says it was his reference doesn't prove anything. Do you honestly think Keele hasn't produced better horns decades ago? But he has also worked for an audiophile magazine.
On-axis response isn't everything. The advantage of a uniform response is less coloration from the room and a much more even frequency response.
So it actually sounds like they may be a better choice than the Faitals for studio use? I did read your extensive report amazing amount of real data! I was concerned that I could get up to 18k usable out of them but if I understand correctly this will not be an issue at these levels?
It qualifies as a subjective impression, not data. I am talking about measured data. The two things are not comparable.
Pete,
I have not heard any Faital drivers yet, and don't know which you are considering, or what horn you are considering, so can't say whether the EVDH1A would be better or worse or sideways.
The EVDH1A /DH1AMT has usable response past 18 kHz, though with a 1.4" exit would probably require a diffraction horn to achieve 90 degree dispersion that high. 60 degrees would be no problem on a conical horn though.
You can listen to the recordings and decide for yourself if the HF sounds like the original. To me, it does, but as I mentioned, I can't hear above 16 kHz, so once equalized flat I couldn't tell the difference between a driver that only makes 16 kHz or one that goes to 30 kHz.
Art
Oh no doubt they do, they have drivers coupling to thin air like the rest. Now if it wasn't for all those platinum records mastered on them or speakers voiced against them......Actually I'm not in love with any of this type speaker, never have been..You are right. It's a rare cool night here in the swamp I'm going to burn them and roast marsmallows right now.
Not all horns or horns + drivers require EQ.
Most, almost all, not all.
Of course dispersion/polar response is another issue, thus the multitude of threads slicing and dicing.
All speakers = significant compromises.
Pick the compromises you can live with, avoid the others = happiness.
Over and out.
_-_-
Most, almost all, not all.
Of course dispersion/polar response is another issue, thus the multitude of threads slicing and dicing.
All speakers = significant compromises.
Pick the compromises you can live with, avoid the others = happiness.
Over and out.
_-_-
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You do not know that it is a subjective impression. That's your conjecture. Go listen with your own ears, then come talk to me. Otherwise it's pointless. You continue to criticize a speaker with which you have no direct experience. Why?
Pointless.
Keele also worked for Peter Aczel which to me says a lot. If more people would have read The Audio Critic after he wised up to the truth the whole industry would have been forced to product waaaaay better products and there would be incredibly less bullcrap. The man is a national treasure. In case anyone ever wonders where I come from read his (free) pdf archives. I felt like I was reading the stuff I would have written if someone had spotted me 30 points of brain.
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Bear opened the worm can and then apparently went "over and out" Cave on mt. Olympus perhaps? So... What *true* horn and driver combo does the true horn thing and efficiently loads the driver especially in the low end but from 500 till "up there" without needing EQ and performs the constant directivity thing too, I'm thinking that this is an "iron law" of some sort breaker, and in lieu of that what is Bear's poison? I'm sure someone knows that huh? Yes I know, I ask the ackward questions, and it would be easy to say "stupid questions, no simple answers" for fear of toe stepping, but someone needs to be the butt and plow through this minefield and ask directly. Fine I will.
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Acoustic lobing, 100% agreed therefore point source for as much of the band as possible. Found that out when I went to wide band 2-way. That equals big deep horns that present a good acoustic impedance to as low as possible so the driver excursion is minimized. Check. I get it. Now, on to diffraction. lets separate smoothly constricted throats from horns with obtuse crap just hanging out in the wind, Like what I consider to be Keeles step backward Mantaray et al.It may very well be that that sort of thing is intolerable and irreparable, Good for theater, everone hears the explicit language equally. That horn is among those I have tried nope. I do not know that all are like that Some like the JBL 2380 etc had those too nope. What I will stake the jewels on is that smooth throat-ed horn such as radials and other "slices of a sphere", and conical are EQ-able to the point of audible minutia. The big Q for me and the big answer for me is going to be hearing a Synergy and deciding if it makes the grade as a reference. Obviously here we have a 90 degree entrance, umm that would be a damn good way to induce un-eqable diffraction error huh? But I heard a Unity and I was impressed, but outside. So the obvious thing as far as I can see here is, as Bear said, the tradeoff.Won't know this until I hear them in controlled circumstances. What I do know is these PeeVee EVee Scalas are remarkable after EQ and alignment. Makes me wonder what else is possible with better drivers. I hope all of this is helping some of us because I feel like a pain here.
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