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Test CD : In Phase / Out of Phase test

I am looking for some help with the following problem?

Many test disks will play in phase and out of phase signals to assist in loudspeaker set up

In phase – my system plays back a signal that is tightly in focus and directly centered between the two loudspeakers. Good.

But, for out of phase – where playback should have no apparent source and seem like it is coming to you from everywhere in the room, my system whilst reproducing a signal that is diffuse and not centered between the two speakers – sounds stronger from the right speaker than the left, like the right speaker is the source.

I have tried the following

1. Changing the toe in of the right speaker so it does not point as directly at the listening position. The problem still remains

2. Swopping the left and right speaker – the problem still remains

3. Passing a 1KHz test tone and pink noise through the system and measuring SPL (dB) 1m from each speaker. The measurements were identical. Taking the same measurements from the listening chair however showed a 2dB stronger signal at the right side?

Any suggestions?
kiwi_1282001
tom6897's avatar
tom6897
1,484 posts
 
You are getting reinforcement from the right side of your room. Have you treated the first and second reflection points for your speakers?
zd542
5,339 posts
 
Nothing is wrong with your system. There are different ways you can be out of phase. In the demo that you are talking about it sounds like the speakers are out of phase with each other. This is not something that you would normally need to worry about. You will never see music like this.

Try this: Turn your amp off and go to one of your speakers (doesn't matter which one). Reverse the speaker cables; if your speakers are biwired, switch both. Just to clarify, put the + (red) on the - (black) and the cable that is hooked up to the - (black) to the - (red). Play the recording that sounded messed up and it should sound normal. Remember, just reverse the cables for 1 speaker, not both.
b_limo's avatar
b_limo
2,274 posts
 
That's funny because whenever my imaging is off, it's always to the right side. I've actually wondered at times if my right ear is just stronger than the left. Moving my equipment from in between my speakers to the back of the room fixed the problem for me. I Agree with Tom though. I think it's down to room treatment and perhaps speaker placement. Are your speakers set up identically?
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