Quote:

alan,
I was under the impression that, for example, hearing the reflection of the right front speaker off of the left wall, reaches your left ear, confusing the Left-Right separation.

In other words, you are hearing the right speaker on your left when the left wall is close. (assuming no treatments)

By the way the image produced in my room by these M60's is absolutely incredible. They are about 10 feet apart and I sit about 11 feet away. The sidewalls are about 6.5 feet away from each speaker. They are toed in about 2 degrees each.





Hi cygnus,

Yes, what you describe does indeed occur but it happens in every stereo playback setup using speakers because speakers radiate sound in a 360-degree sphere, with output that varies with the acuteness of the angle away from the front of the speaker. As you may be aware, low frequencies from 80 Hz on down, are essentially omnidirectional--they radiate with equal intensity in every direction.

The phenomenon you describe is "crosstalk"--sounds from the right speaker reach your left ear and vice-versa, which narrows the stereo image. The only way to avoid this is by listening with headphones or by using a crosstalk-cancellation circuit (that's what Bob Carver's "Sonic Holography" did as well as some tower speakers from Matthew Polk quite a few years ago).

You cannot eliminate crosstalk by absorbing side-wall reflections, nor do you want to. Bridgman's comments here are entirely sensible. A mix of absorbent and reflective surfaces in a given room is what to aim for. You do not want to turn a listening room into an anechoic chamber or a "dead" listening space. The latter was in fashion by some studio control-room designers for a time (called "live-end, dead-end" or maybe it was the opposite. . .).

There is a pervasive tendency to want to over-treat domestic rooms in terms of reflectivity/absorbency. Of course some really bad rooms do need treatment, but in many cases, the usual mix of domestic furnishings are very effective--rugs, bookcases, carpet, some bare surfaces, etc.

Introducing crosstalk-cancellation techniques is misguided because recordings are not produced or mixed in that fashion, and when they are played back with crosstalk cancellation operating, truly bizarre effects may occur. It's fun hearing them--it only works if you sit exactly in the sweet spot--but much of the time the effects are unnatural.

If you've found a spot for your speakers that delivers a seamless soundstage and spacious quality to the playback from where you listen, then great. I'm not telling you not to tweak, but stereo playback has a number of intrinsic flaws (crosstalk, comb filtering) that no amount of room "treatment" can overcome.

Alan Lofft,
Axiom Resident Expert (Retired)