Interaural Crosstalk And Loudspeaker Setup


When listening to two channel stereo audio reproduction sounds from the right channel loudspeaker are heard by both the listener's right ear and left ear.  Sounds from the left channel loudspeaker are similarly heard by both the listener's left and right ear.  This fact has been labelled interaural crosstalk.  Here's a brief discussion of it from the Steve Hoffman forum.

Interaural crosstalk can be enhanced or diminished via electronic means and even by the physical design of the loudspeaker.  Can it also be accomplished via loudspeaker placement and acoustic treatments?  Toe-in could be a tool, but I'm thinking of a setup I saw back towards the end of the last century.  I remember visiting a retailer who had a large acoustic panel, maybe 6 ft by 6 ft, that was supposed to be placed between the loudspeaker, but perpendicular to the plane of the loudspeakers.  The idea was that the panel would lessen the crosstalk at the listener position.  I never heard a demo of the product so I have no idea if or how well it worked.

Does anybody have experience with setting up their listening space in this manner?  If so, what did you think?  BTW, I've look at near countless virtual system pics and I've never seen this layout.  That should tell me something, but maybe not.

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I installed the BACCH system a few months ago.  The head positioning is not critical if you buy the head tracking camera option.  It's simply addictive.

Can't live without it.

The one single thing that bothers me most about interaural crosstalk is the cancellation dip that occurs at the ears for the phantom center. For a typical 60 degree triangle this first dip occurs around 2 kHz, which is about as bad a place for a dip that you could ask for, taking the crispness and articulation out of center panned vocals and instruments.

If you push the speakers closer together you can push the first cancelation frequency up higher. That's good, but then the stereo effect is also minimized. If  you push the speakers wider apart, that will push the first cancel down below 1 kHz, which I found is also good, as the upper frequencies will not get comb filtered as severely because of improved head shadowing. 

Lately I've been listening with about a 110 degree triangle and find this very satisfying in terms of giving a crisp, clear sounding center image. I get the impression that for me, late reflections can fill in below 1 kHz with less perceptible loss in clarity and presence than up at 2 kHz. 

I've also tried various crosstalk reduction methods, including a 3 speaker array that I dreamed up. They work, but seem to always come with a side effect or two. I haven't tried BACCH, but I tried a competitor product that sounded excellent. It didn't overly widen the soundstage while also producing an excellent tone and clarity for the phantom center. My main issue with it was latency from the processing. The other was that it needed the speakers to be closer together, and my room layout works better when the speakers are spaced wide apart, which to my ears sounds about as good overall. 

The best I've heard is from using a physical barrier. It's exceptionally clean and pure sounding, creating . I also think the arrangement ends up improving room acoustics considerably because it ends up dividing the whole room's early reflections into more exclusively left speaker reflections on the left side of the room, and right speaker reflections on the right side of the room.

Mechanical separation of speakers is not for everybody but it works for me too....