Test CD : In Phase / Out of Phase test

Using the in phase/out phase track to position your speakers/listening spot may result in the best positioning for soundstage/imaging info, but it will not necessarily give you the smoothest tonal balance.

I guess I will clarify, too. The Test CD I was referring to is the XLO Test CD. TRACK 4 is the Out of Phase track for determining speaker locations without guesswork. The methodology of the Out of Phase track on the XLO Test CD eliminates a lot if guesswork involved in trying to find the optimum speaker placement in a given room strictly by ear. The problem with the move a little/listen a little method for speaker placement is you never know when you've found the optimum location. That's the beauty of the XLO Out Of Phase track - you can find the absolute best locations for the speakers. The disadvantage, if you want to call it that, of this methodology is that you have to address room anomalies in order to get to the point where you start hearing the effects of the Out of Phase track - where sound seems to be coming at you from all around your room, even from behind you. Unless room acoustics are addressed minimally it's virtually impossible to hear what they're talking about. As an old philosopher once said, "It ain't easy McGee."

Using Stereophile test CD2 in my main system, I achieved results similar to yours. My speakers are not equidistant from the sidewalls. The whole system is shifted to the left side of the room and my listening position is centered between the speakers. In addtion to that, neither sidewall is similar as far as surface is concerned. Since the system sounds fine otherwise, I won't worry about it.

In my secondary system which is my reference system, the speaker position and the room are much more symetrical. The result here was an even shift between channels and a lack of central specificity. I never did sense the out of phase signal to envelope or wrap around the listening position. The speakers are postioned quite close to the sidewalls in this room with a fair amount of toe in. The seating position is also closer than in my main system.

You could experiment with some alternate speaker positions or try a few absorbers in different areas and see what happens.

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.

I was in a hurry when I typed out my response this morning. Also, with the posting delay, things can get confusing. The last post I see is Kiwi from today, the 3 paragraph states he will try my recommendation (zd542). Just to keep context, this response in response to everything up to the post I just mentioned.

Something I need to clarify. When you say test discs, I'm taking that literally. These are actual recordings that are to be used in the set up and evaluation of audio equipment. That's what I'm going on. If the recordings you are referring to are just a bunch of well recorded, audiophile pressings of music that are great for really testing a system, then my first post probably doesn't apply.

The reason I said that there is nothing wrong with your system is that the phase test that you describe, should sound messed up. Its typically used to show what a system will sound like if you made an error connecting your speaker cables. If that's the case, there really is nothing to fix. I had a look at the 2 systems you have listed. It looks like you really know what you are doing and take audio very seriously. Given that, I just don't see you messing up connecting speaker cables. That's why I say there is nothing wrong with your setup.

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.

It takes a lot of playing around with room treatment and speaker placement
to be able to get the out of phase track to sound like it is coming at you
from all around your room. But when the room has been treated properly,
I.e., primarily, but not limited to, with respect to echo and reflections, etc.
and you find the exact location for the speakers then you will hear the
sound all around you equally. But it is not something one can necessarily
obtain overnight. Tip: try placing the speakers closer together than you
normally would, say four feet apart with no toe in/toe out. Then play the out
of phase track to see if that improves the effect. Gradually move the
speakers farther apart and see if you can pinpoint the speaker location
where the out of phase track sounds best, when the sound appears to be
coming from all around the room equally, even from directly left and right of
your listening position and behind you.

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.

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?

You are getting reinforcement from the right side of your room. Have you treated the first and second reflection points for your speakers?