I may have been incorrect in my earlier post. I didn't realize the LFM-1 has only one input jack. You may want to try connecting it with a mono RCA to RCA cable and see what happens. I apologize for any confusion.

"The Matrix" should be fine for test material. If you have any "THX" certified DVDs, there's a great bass sweep in the "THX" optimizer. It's a tone sweep that goes from 200hz to 20hz. That kind of sweep is great for hearing what your crossover is doing and also what the bass frequencies are doing in your room.