Setting Sub Crossover Freq

80 hz..............

80Hz. The universal solvent. ;-)

80HZ, I like this...this is the Ron Popeil solution: set it and forget it.

Potential for lots of overlap, bloat, & slurring with crossover up that high. For comparison try 40hz at both 12db/octave and steeper 24db/octave roll-offs. This may clarify the critical mid-bass and shift the transition between bass drivers into less audible LF region. Less can be more...

I agree, you have to set the crossover point LOWER than the bottom of your regular speaker. Then adjust the integration using the sub's volume control. Don't forget to check the phase of the sub also.

I agree that a sub sounds better out of a corner for music. Corners make for bigger THUMPS, which may be fine for home theater but loses character and texture on music.

If you can hear the sub then it is probably too loud. The integration should be seamless and not noticeable, else it's not set right.