Originally Posted by Still lll
Would there be a difference if I used LFE vs line in with phase/delay set to 0?
If you set it to phase 0, AVR/12, and turn the crossover frequency all the way to the right, then line in becomes like LFE. With LFE, there is no low-pass crossover to the sub. If you set line-in like I said, the low-pass crossover is set so that it has virtually no effect. If you use the bass management in a pre-amp/receiver that applies a crossover, you usually want to do one of these, so you don't double-up the crossover. If you are getting high frequency noise to the subwoofer from the LFE jack, sometimes it's useful to switch to line-in, so you can filter out the noise. Also, if you need to the tune phase with your sub rather than your pre-amp/receiver, you need to use line-in. This is useful if your receiver only has a single sub out jack and the speakers are different distances.
Here's the ideal setup, in my opinion. (Some of this assumes a rectangular, closed room.)
1) Pre-amp receiver with 2 sub outs jacks.
2) 1-2 equidistant (with each other) subs in the front corner(s) of the room, using the 1st sub out.
3) 1-2 equidistant (with each other) subs in the back corner(s) of the room, using the 2nd sub out. Use opposing corners for 2 subs, 4 corners for 4 subs.
4) Plug into the LFE inputs on all subs.
5) Set all speakers to small, even if they are large.
6) Crossover at 80hz usually works well, but you may need to go up for small speakers. I haven't had much luck going lower, even for large speakers.
7) Use the receiver to automatically or manually set distances (delay) to the front sub(s) and back sub(s) to time align with each-other and with speakers.
8) All subs are identical.
9) Some form of sub EQ (Audyssey XT32, external sub EQ, built-in sub EQ).