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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

Showing 2 responses by kiwi_1282001

kiwi_1282001 OP
312 posts
 
Tom6897, zd542, B_limo and Geoffkait, thank you all for your comments.

My room is treated for early reflections (sidewall, floor and ceiling). Speakers are set up similarly. more details on my set up are here. See mid-page for photos.

I will try out your recommendation zd542.

Yes B_limo I too wondered about my hearing hence resorted to taking some basic signal level measurements to see if what I was hearing was measurable. At the listening chair the signal was definately higher (about 2dB). Overall, the out of phase signal does sound out of phase i.e. diffuse and non centred.

I will try that Goeff. As theory goes - the better the out of phase response you have - the better in phase response you should have, hence the effort here.
kiwi_1282001 OP
312 posts
 
hello again Zd542.

My response was rushed to. I guess that is modern life.

To your question, yes, I have test CD's from Chesky Records, Nordost and Stereophile. These test CD's carry a number of audio tests which include channel identification, phase, LEDR, test tones, signal sweeps, absolute phase, burn in tones etc.
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