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

Showing 1 response by corelli

For clarity, do you mean the front wall???  

Think of it like this.  When you go to a performance, are the performers in front of you or in back?

Dipoles are unique and enjoyable speakers.  As noted above, embrace and don't destroy the rear wave.  Use diffraction, NOT absorptive surfaces on the front wall.  Why would you want to defeat what this design type is all about?  If you can't pull them well off the front wall you will miss out on what these speakers can do.

For me, in the final analysis, dipoles are fun but not always the most accurate.  But in the right room with the right music, well you may be a very happy camper indeed.