What's phase 0 degree - 180 degree?

Actually, DT, you have found the solution to all your questions just by experimenting. But you need the technical reasoning behind it all, which I will try to help with.

1. Phase is whether the speaker cone is moving out with a signal that is also moving out. Think of a trumpet blast as an outgoing phase launch, one can feel that air move towards you. Another example is talking vs. talking while breathing in (yes, it sounds weird). You might say it should always be 'in' phase or 0, but some electronics change the absolute phase of the recording simply by the number of stages of amplification they have in them (even - in phase, odd - out of phase).

2. This is the easy one. You want the one that "fights" less with your main speakers, meaning your speakers are in one phase and your sub in the opposite, creating cancellations. And that means....more bass output. So 0 is correct.

3. It depends on your ears; if the crossover is fairly high, you may hear a hollowness in the music. But set it at 0 and you'll get to listen to all the bass you paid for.

Hope this helps!

Tsouthworth is right on the money. My preamp inverts the signal so I must swap speaker leads minus to plus and plus to minus. With your setup I would only have to flip the switch.

worldcup...for a detailed explanation to your questions let me refer you to lars fredell's article on the subject in the summer 2000 issue of ultimate audio mag. the terms 'phase' and 'polarity' are used interchangably most of the time.when cds or sacds are recorded they are recorded either in 'phase' (absolute polarity)( 0 degrees) or out of 'phase' (reversed polarity)(180 degrees).recordings that are 'in phase' or absolute polarity' will have deep taut bass good sense of air and transparency and dimensionality.those out of phase ( reversed polarity) will have bass that is not as deep or taut,sibilance might be too pronounced and strings too glaring.( i'm quoting lars here)the 0 degree and 180 degree designation on your sub allows you to dial in absolute polarity or switch it 180 degrees. some record companies cds and sacds (sony for one) are recorded out of phase.(the U.A. article has a list of recording labels and the usual polarity they record in).i would get the mag. and refer to the list when playing cds or sacds and play with the switch. your ears can usually,like yours already have,tell when a recording is 'in phase' or 'out of phase' ( absolute polarity or inverted polarity) hope this helps a little. dave smith 'calloway'