Back in the days of matrix quadraphonic, I experimented quite a bit with phase issues. If your preamp has this capability, here are some interesting things you might try.
1. Run one channel inverted all the time, and reverse the speaker wires to compensate. Since most of the music signal is common mode (same in both channels) your power amp will work better because the draw from the plus and the minus power supplies is evened out. (Dynaco specd their old Stereo120 amplifier at 60 watts per channel (with channels driven out of phase). That last part, in parentheses, was in very small print.
2. If your amp can handle the low impedance (and most will because of item 1 above) bridge the power amp with another speaker. Presto! Instant center channel with perfect phase relationship to Left and Right, differential configuration for lowered distortion, zero cost for amplification, and having twice the power as appropriate for the center (common mode) signal.
3. You can achieve perfect Left/Right channel balance (very important for matrix multichannel) by puting the phase back to normal, playing a Monaural signal like FM interchannel noise, and listening for a null (silence) from the bridged center speaker (or earphones). In my case, in addition to adjusting the Balance control, I needed to touch up the Tone controls to get a perfect null.
There is lots more fun to be had fooling around with phase. Enjoy.
1. Run one channel inverted all the time, and reverse the speaker wires to compensate. Since most of the music signal is common mode (same in both channels) your power amp will work better because the draw from the plus and the minus power supplies is evened out. (Dynaco specd their old Stereo120 amplifier at 60 watts per channel (with channels driven out of phase). That last part, in parentheses, was in very small print.
2. If your amp can handle the low impedance (and most will because of item 1 above) bridge the power amp with another speaker. Presto! Instant center channel with perfect phase relationship to Left and Right, differential configuration for lowered distortion, zero cost for amplification, and having twice the power as appropriate for the center (common mode) signal.
3. You can achieve perfect Left/Right channel balance (very important for matrix multichannel) by puting the phase back to normal, playing a Monaural signal like FM interchannel noise, and listening for a null (silence) from the bridged center speaker (or earphones). In my case, in addition to adjusting the Balance control, I needed to touch up the Tone controls to get a perfect null.
There is lots more fun to be had fooling around with phase. Enjoy.