Speaker Phase and Avia



<font color='#000000'>Hi, Newbie with a (simple?) question

I have a set of DCM Time Window 1A speakers. I ran the Avia Speaker Phase test and lost the phantom image for 1.5 seconds and heard the phantom image for 0.5 seconds.

I changed the electrical phase of the right speaker as recommended by the DVD and it corrected the acoustic phase: 1.5 seconds phantom image and 0.5 no phantom image.

I checked the electrical phase very carefully when I hooked up the speakers and rechecked it after the Avia DVD told me I had it wrong. It was correct in the first place. The correction to get the Avia test to pass reversed the electrical phase on the right front speaker.

When I played a stereo source (with the right front speaker electrical phase revered) the stereo image seemed “weirdly” there but, I got the feeling that the right speaker was not as loud as the left. I corrected the electrical phase of the right speaker (+ to +) and the image returned to the “sweet spot”.

Can someone educate me on what I’m hearing?</font>


<font color='#000000'>It's possible that your right DCM's internal wiring is wrong, but it's equally possible that the test DVD is defective or you're misinterpreting the results. I'm not familiar with the Avia test per se. There are a variety of ways to test speaker polarity, but I think that a very low-tech method is usually adequate: in most cases, whichever polarity results in the most (subjective) bass response is the correct polarity.

Also, you speak of the stereo image being &quot;'weirdly' there.&quot; Do you mean weirdly as in uncannily good or weirdly as in just weirdly?</font>


Audioholic Intern
<font color='#000000'>I had a little trouble with Avia in that regard too.  I tried that test on a few occassions, and I get very inconsistent results.  Sometimes it seems correct, sometimes I think I want to rewire my speakers.  

But physically checking the wires shows that I am in phase.  Weird indeed.</font>


<font color='#000000'>The proper phasing between left and right speaker can usually be checked as follows. &nbsp;Play a mono signal, reverse the connections to one of the speakers (reversing its phase) and listen again. &nbsp;One way or the other, the mono image should seem much larger and more diffuse, and THAT is the out of phase condition. &nbsp;If it sounds equally diffuse either way, then one of the speakers may indeed have an internal wiring problem, such that its own drivers are not properly &quot;in phase&quot; relative to each other.

Try testing with a mono signal. &nbsp;Correct phase is usually very easy to spot this way.


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