How to set crossover settings on the amp?

[Birdie2000]

This has puzzled me for a while, and I think it's holding back my system from really sounding good. There's a bit of a gap between my sub and my components. I do know that setting the crossovers is something that you just have to listen for most of the time, but how do you figure out where you're crossing over with those little dials on the amps? I always hear everyone say that they're crossing over at 80Hz or 60Hz or sometimes even the oddball "63Hz", well how do you know that? Granted I've never used any "high-end" amps to know if they're any different, but all the ones I have used the little dials don't have any clicks or anything to tell you where you're at. I used test tones to set this on mine and got it to the point that 80Hz is barely audible from my components, but because of the slopes I really don't know what my "crossover setting" really is. I know I'm just going to have to mess with the knobs some to get the sound I want, but I'd really like to know how everyone figures out exactly where they're crossed over so I can figure it out when I'm doing it. :)

[DSZ71]

Its all testing and trial and error. A setpoint in my truck may not work well in yours. Just play with it for awhile (hehe)