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Dipole speakers, subwoofers and that rear wall

I own modern quad dipole speakers (2912s). I’ve heard many stories about speaker position, but never something that rang as fully logical to me. I can imagine 3 choices:

 

1/ dipole pretty much against the wall, maybe slight toe-in. The reflecting sound will come quickly after the straight sound and might cancel out the direct wave

2/ dipole far from corner (I hear quad recommends 1.5m). Reflections will amplify the sound?

Both statements feel like they’re incomplete. Surely the frequency, or frequencieS being played matter a lot if the reflected sound is in phase (amplifies) or in antiphase (attenuates) the direct sound. I can imagine perfecting positioning for one frequency and its modes, but not for 20-20,000 hz full spectrum.

 

3/ Close the rear of the dipole or have sound-absorbing material behind the speaker

The third one seems somewhat more logical, since I can’t imagine a sinewave that’s being attenuated by a reflected wave being accurately-sine-y unless the reflection is exactly in counterphase with the frequency played.

But on the other hand, if I have an actual instrument that is somewhat reminiscent of an actual dipole (e.g. a snare drum pointing upward) will have similar reflections on the rear wall.

 

I guess it "feels" true that you don’t want to stuff a musician in a corner too much but I’m not sure if this will negatively impact his sound?

 

As for the second part, a proper subwoofer moves quite a bit of air, can that air damage a dipole eletrostatic speaker?

puntloos
helmholtzsoul
111 posts
 

It’s a timing issue, the front wave vs the back. The front wave hits the seated position, when the back wave is hitting the front wall. No matter where you put the front baffle, the rear of baffle has to travel further. Longer rooms help. Our user group went through this with 123s, 20 years ago. (GRs adopted nightmare). We or he could NEVER fix the problem. I must admit we all agreed they look awesome and have great sound effects, but most simple stand mounts speakers will whip the pants off dipoles. The only place they fall short is "SOUND EFFECTS" if that is your thing. I like a rear firing separate driver (s) for the back of the main cabinets. We ALL use SB/SAT design.

Subs are simple. Decouple the subs and raise them UP. Set them on tunable bass traps or between them, OFF the ground.. It’s like magic. Vs works very well in leu of conventional DBAs. The V baffle is at 30 degrees, the flat rear is a passive radiator. There are THREE directions the sound is coming from with a single cabinet. Two units placed on either side of the seated position is a full blown DBA less 2+ extra cabinets. It’s all the rage with US poor boys.. Again SB/SAT design.

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cleeds
5,695 posts
 
onhwy61

The rear wave is not the enemy. Embrace it!

Exactly! A dipole’s radiation pattern is part of what creates that open, spacious sound that box speakers struggle to produce.

helmholtzsoul
111 posts
 

I "Embrace it" in a tuned chamber vs trying to tune the WHOLE room to the open driver. It can sound wonderful, but NEVER accurate. I've had to Endure dipoles more than Embrace them.. I had IRS Betas for 20 years. Wonderful speakers for the money. I did everything to those speakers.. Including "Embrace", I even divorced them a few times too. 20 year love hate relationship. :-). I really liked the servo bass columns. My first real DBA (4 servo columns). 1980-2000.

sbank's avatar
sbank
3,378 posts
 

check out the room treatment page on soundlab's website for dipole specific recommendations (live end / dead end). Cheers,

Spencer

Ag insider logo xs@2x
cleeds
5,695 posts
 
helmholtzsoul

 "Embrace it" in a tuned chamber ...

What is a "tuned chamber?" I've never heard of this room treatment.

It can sound wonderful, but NEVER accurate ... I had IRS Betas for 20 years. Wonderful speakers for the money. I did everything to those speakers. ... I really liked the servo bass columns.

Yup, the IRS bass columns can be terrific. I'm still using my IRS Beta system. I sometimes makes my own recordings, so I know that they can be reasonably accurate.

If Infinity made a mistake with the IRS Betas, it was the degree of flexibility in the adjustments. That's a double-edged sword: Used properly, the system can sound fantastic. Used improperly and you get that "hi-fi" sound that quickly wears on the listener.

 

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