[turkey]

This myth of a sweetspot that 4 people can sit in baffles me. I don't care what crazy engineering you put into a speaker there is one sweetspot and it is approximately as wide as a human head.

With my system, it depends upon the recording. Multi-mono studio recordings which attempt to form a soundstage using a pan-pot play over my speakers with a "sweetspot" that's large enough for 4-5 people. I bet I could make it larger if I had a larger listening room.

Recordings of acoustic performances that are actually in stereo are a bit different. Tonal balance and timbre are the same for 4-5 people sitting side-by-side. Imaging suffers a bit as you move away from the center, but still isn't limited to "the size of a human head."

I suspect that the difference is that my speakers are really CD, and part of the reason they're CD is that they use properly implemented waveguides.

[BobRex]

Do it DO IT for the lOve of all things holy and hellbound!!!!! DOOOOOO IIIIIIITTTTTT!!!!! Nothing on earth is more wondrous than the 40s pushed with a pair of awesome SET amps.

I can confirm this, I'm running 2A3s on the mids and tweets of a pair of RM30s.  I use the 500W BPS below. With the right recordings it's GLORIOUS!!!

[woodsyi]

Are you bi-amping or tri-amping:  Mids and Twit driven together or separately?

[satfrat]

Of course this too comes with its own set of compromises and one of those is, that as you disperse the sonic energy over a larger area, it is reduced in SPL.  This then requires a change in the XO to compensate to a degree to that change.  Even then a direct comparison of "off and on" will simply demonstrate that one has the ability to play louder than the other, which is simple physics.  But while playing louder, the "OFF" sonic will then again be restrictive to the listening position.

I don't understand why a lower db while using the CDWG would even be considered an issue if you've got an amp with the balls to push these loudspeakers in the 1st place? Simply touch up the volume to rectify and enjoy a wide sound stage dispersion verses a narrow direct sound stage. Me, I value a deep wide sound stage so if I owned VMPS, so chances are I would welcome the CDWG's with open arms. 
 
But then again I've never owned VMPS loudspeakers or experienced CDWG's on the 1 time I actually heard them (Zybar's old pair). And I do like A1 Bold & Spicy sauce on my filet mignon. 
 
Cheers,
Robin

[John Casler]

Do it DO IT for the lOve of all things holy and hellbound!!!!! DOOOOOO IIIIIIITTTTTT!!!!! Nothing on earth is more wondrous than the 40s pushed with a pair of awesome SET amps.

Unless it is a pair of RM v60, or RM 50 pushed with same.

I am sure Big B, loves to hear your enthusiam for your 40's.

[John Casler]

I don't understand why a lower db while using the CDWG would even be considered an issue if you've got an amp with the balls to push these loudspeakers in the 1st place? Simply touch up the volume to rectify and enjoy a wide sound stage dispersion verses a narrow direct sound stage. Me, I value a deep wide sound stage so if I owned VMPS, so chances are I would welcome the CDWG's with open arms. 

Hi Robin,

It is actually not an issue except for those who perform a "direct" comparison, (which is very hard to do due to the difference in SPLs) and quite often such a comparison tends to not demonstrate the best qualities of each, since without changing the OX for each, the comparison will suffer.
 

But then again I've never owned VMPS loudspeakers or experienced CDWG's on the 1 time I actually heard them (Zybar's old pair). And I do like A1 Bold & Spicy sauce on my filet mignon. 
 
Cheers,
Robin

I have A1 Bold and Spicy just waiting for you

[satfrat]

Hi Robin,

I have A1 Bold and Spicy just waiting for you

Yes you indeed do John. 
 

 
Cheers,
Robin

[John Casler]

This myth of a sweetspot that 4 people can sit in baffles me.

When you have constant directivity, the sound disperses equally from each speaker in a hemispherical pattern.  The better the directivity, the better the imaging.

Each speaker creates this pattern, so that (in theory) no matter where you sit across the front, the sound your ears receive from "each" speaker is balanced and equal.

This is in comparison to a speaker that has a more tightly focused dispersion with "less" sound as you move off axis.  In this scenario, your ears will then hear the closer speaker and the image will collapse to the speaker nearer to you.

Now there are numerous other factors that can influence this imaging such as HRTF (head related transfer function) and even the reflective properties of the walls you are then sitting nearer or farther away from.

I recall at CES a few years ago when Brian introduced the CDWGs, I ran the room standing all the way on the left wall.  Normally that would have put me closest to the left speaker and the imaged would have collapsed to the left, since that speaker was closer.

With the CDWG on however and with my head facing the center of the stage as if there were a perfromer there, the image of the singer was dead center between the speakers and the stage spread across the room.

I don't care what crazy engineering you put into a speaker there is one sweetspot and it is approximately as wide as a human head. You can put a CDWG or have an omnipole speaker like the German physics and still, you have a sweetspot as wide as a human head. That isn't to say that outside of the sweetspot the sound isn't more "even" with the CDWG or an omnipole, or that the speaker won't image in some way even if it is inaccurate to the recording, but nothing you do to a speaker will make it sound as good outside of the human head sized sweetspot period, so IMO something like the CDWG is nothing but a compromise regardless of whether you're in the sweetspot or not. It will sound more even outside of the sweetspot, but at the cost of everything else I wrote above.

That is true.  The most accurate and precise images and soundstage will occur as you suggest, but just as many don't care if their speakers hit bass below 40Hz, or if they have a certain type of tone, resolution or detail, they want the old goal of "spreading it across the room".

You find some also have the same concern with the "viewing angle" of their Plasma, Projector, or other video display, even though 99% of the time any serious screening is done directly in front of the screen.

It is simply F1 or M3.  Everyone can take their pick, and get the sound closer to what they prefer.

[John Casler]

I have a pair of RM30-C's with the CDWG coming next week and I'll be driving them with a 50WPC EAR 534 push pull EL34 amp. Although I enjoy pinpoint imaging, the notion of having a soundstage that is discernable from different off axis locations is compelling. I heard this effect at the california Audio Show in the Acapella room and it was impressive. I'll listen both ways and report back.

Hi Wy,

(Looking forward to seeing you at THE Show by the way)

Unless, you have the D-OXO, with two separate equalizations, the comparison won't give you a true reading of the capabilities of each since the XO and dehorned tweeter will not be exactly proper to the the "CDWG off" use.

"Theoretically" in an Anechoic Chamber the properly equalized CDWG on should have the capability to offer the SAME pin point images and stage structure.

In fact if it performs as it should the actual imaging and stage should be STUNNING all across the room.

But very few of us listen in such a reflectionless environment so the spectre of more "indirect" sound raises its little hand and can cause distortions that detract from the direct sonic.

[Pez]

John,
I say screw the other people in the room dammit! I paid for the system I put it together I want the uber sweetspot!!!!!
 

[John Casler]

John,
I say screw the other people in the room dammit! I paid for the system I put it together I want the uber sweetspot!!!!!
 

That describes "my" personal 2 channel system exactly.  You don't see a "side car" on a Formula ONE ride.  It is UNO only.

Hey when a friend comes over I put THEM in the sweet seat so I can blow their hair back a little.

I've alread been there, and the hair is gone anyway

[Hipper]

I've got long hair and I find for a better sound I need to move it behind my ears!

Checking the internet it seems the frequency absorption of human hair and skin is in the range 1-6 kHz so my hair movement is justified, but should I also remove my skin?

[BobRex]

Are you bi-amping or tri-amping:  Mids and Twit driven together or separately?

In my case I run both the mids and tweets off of the same amp.  Since the mids have a 93dB sensitivity, it works quite well on 3.5 watts.  One of these days I'm going to throw a cap in the amp's input as a high pass filter around ohhh, maybe 240Hz.  That should open up the amp a little further.  I was also thinking about one of Roger M's EM7 amps, maybe the 5 watter, assuming he still makes them.

[Pez]

With the rm30s I'm not surprised you're able to run 3.5 watt 2a3s. But I am also almost certain you are hitting your head dynamics-wise. You should consider triamping.

[turkey]

I recall at CES a few years ago when Brian introduced the CDWGs, I ran the room standing all the way on the left wall.  Normally that would have put me closest to the left speaker and the imaged would have collapsed to the left, since that speaker was closer.

With the CDWG on however and with my head facing the center of the stage as if there were a perfromer there, the image of the singer was dead center between the speakers and the stage spread across the room.

The CDWG is a diffraction device.

Sometime you should try to audition speakers that are truly CD and are also designed to avoid diffraction.

[John Casler]

I've got long hair and I find for a better sound I need to move it behind my ears!

Checking the internet it seems the frequency absorption of human hair and skin is in the range 1-6 kHz so my hair movement is justified, but should I also remove my skin?

I don't think so,    but for people who wear glasses, they should remove them.

[PLMONROE]

John, the next thing I know you will be suggesting that  we disrobe and try listening in the buff!  But now that I think on this, just consider the interesting possibilities.   

Paul

[Brian Cheney]

The CD devices which do not employ diffraction slots also do not provide constant directivity with frequency beyond about 14 kHz.  Our CDWG does.

However, it does introduce HF rolloff and cuts sensitivity in the midrange.  I have a new version of the CDWG which eliminates both problems.  Sorry, had to wait for the patent to issue.  This version is add-on, inexpensive, and available in about two weeks!

[fredgarvin]

The CDWG is a diffraction device.

Sometime you should try to audition speakers that are truly CD and are also designed to avoid diffraction.

Turkeys have weird fleshy tumor-like objects that hang in front of their faces. It makes you wonder if what they say makes any sense. They also sh*t a lot in unwelcome areas.

[Pez]

Interesting Brian. Hopefully it will be a better add on than the current CDWG for those of use who have your speakers already.