Thanks for the advice on the JL amp. Actually, the sensitivity is already set on high and the bass boost is turned off. If it helps any, the inputs to the amp come from a speaker level adapter mounted behind the stock head unit. I don't know why I had to pay for the adapter considering that the amp has speaker level inputs, but thats what I have. I haven't fiddled with the input sensitivity setting, I've just been taking my installer's word for it that it's turned down all the way.

Stu