Left / Right Maddening Problem


Hello all,

I have a conventional 5.1 HT / music system: DVD, CD, Pre-Pro, front amp, 3-channel amp for surround and center and self-powered sub.

For a test CD, I use the Stereophile Test CD 002-2, which provides a dog barking to verify left and right channels, a bark that should come from between the two front speakers and an out-of-phase dog bark.

Both the CD and the DVD (with the center and rear channels turned off) exhibit the same anomaly: the left dog emanates from the right speaker, while the left dog comes from the center. Neither is distorted. The center dog bark is perfectly placed and undistorted. The out of phase dog is indistinctly located and somewhat muffled - which is the expected behavior.

Since the CD and DVD are connected to the pre/pro at separate inputs, I think I can rule out the units themselves as being at fault.

I changed the front amp and got the same result. I changed the pre/pro and got the same result. I changed the connecting cables from the CD and the DVD, which also made no difference.

I deliberately reversed the power and ground on one front speaker, which did not help.

Also, I ran the test setup from the pre/pro to make sure that left and right speakers are correctly connected and identified by location.

Lastly, I played the test CD on a boombox to be sure that it does, in fact, produce the dog barking from the left and right side speakers - which it does.

So, now I am unashamedly stumped and am appealing to you all for help. (My wife would also appreciate a resolution to this issue since my testing is making her nuts.)

Any and all suggestions will be welcomed.

Thanks.

Jon
opteron05
Opteron05: That is quite interesting. You have done just about everything possible to make it work. It is curious that the CD works on a separate system (your boombox) but not in your main system. I have had, on rare occasion, a newly burned CD that would not play at all in my PC system but worked just fine in the main system elsewhere. Perhaps you could try another copy of the test CD. Just a last ditch suggestion!
Another last ditch suggestion: look into speaker placement and room effects. Is your room symmetrical, for example? My rear wall has a 12-inch step on the left side and when my speakers are not precisely toed in the image shifts to the left.

My reference on this subject is Jim Smith's Get Better Sound.

http://www.getbettersound.com/
How would a Test CD designed specifically for 2-channel audio correctly operate in a 5.1 channel home theater system? With a 3-channel amplifier how would the audio input channels be separated and distributed if there are only 2 to begin with? The Test CD works correctly with a 2 channel amplifier (the boombox) but not with a Home Theater processor/amplifier. Have you tried using a Test CD designed for 5.1 HT?
Thanks, Puerto.

Puerto: I can certainly try duping the CD, however, if I make a truly accurate copy, I would expect it to perform just as the original has. I will give it a try and let you know what happens.

Jon
Thanks, Tobias.

This is a provocative approach. I have tried to keep things as symmetrical as possible (the room is 10 x 18 with curtained windows along one long wall and seating along the short wall). Ordinarily, I wouldn't expect the bit of difference to cause as much imbalance as I am getting, but this is worthwhile trying as well. I'll get back to you.

Jon