Posted by Wayne Parham [ 70.234.106.162 ] on July 19, 2008 at 17:36:38:

In Reply to: 4-Pi Phase shift??? posted by wayne-o on July 19, 2008 at 14:35:22:

The room has much more effect in the modal region than the phase of a single sound source. Summing is pretty complex of the direct sound from woofers in different locations in the room and all all the reflected energies from the walls, ceiling and floor. So in a small room, acoustic phase of a single bass sound source measured in an anechoic environment doesn't mean very much.

Generally speaking, the more woofers you put in your room, the better. They'll smooth the sound field by averaging, with peaks from one speaker or reflection countering the nulls from another.

Above the modal region, phase of a single sound source becomes more relevant. But it's still really a matter of summing between sound sources that you really care about, because you can't hear phase directly. What you hear is the anomalies in amplitude response that result from phase interactions.

Acoustic phase and amplitude response of the four π loudspeaker is shown below.

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