My amp (Musical Fidelity A3.2, an integrated amplifier) has a preamp (line level) out. I'm assuming it's the same signal that goes into the main amp section. Obviously, I'm running that into the RCA line-level input of the subwoofer.

But I'm confused about a couple things.

First, although I'm using my ears instead of a meter, it sounds like my MMGs have a fairly flat response down to about 55hz. So why would I set the crossover as high as 80hz? Wouldn't this necessarily create a hump in the 55-80 range?

Perhaps my problem is that I don't know the slopes of the rolloffs for the two speakers, so I'm having a hard time picturing this all in my mind. Perhaps I should just bite the bullet and get an SPL meter. Is a $50 digital Radio Shack meter going to be more accurate than my ears?

I experimented with a large range of crossover freqs, and found that anything as high as 80hz made it really boomy on any recording with substantial bass; if I then back off on the subwoofer gain to eliminate the boominess, it becomes difficult to tell that there is any subwoofer at all. No matter what I do, it seems like I still get a dip at 65hz, which makes me think it's a room problem.

I will say that at 40hz, I'm still having a hard time getting a good rock and roll punch.