I'm sure that many of you out there have installed aftermarket amp-cap-sub systems to your stock stereos. Seeing as the stock head unit has a changer and tape deck, I'm going to hold onto that for a while and upgrade the cabin speakers and install a sub from my previous car.
So I have to run a line-out converter to the amp off the rear speaker channel, and I was wondering what brand/model of line-out converters you would recommend. Have any of you had problems with engine-generated noise in your set-ups? Are there recommended converters with good shielding? Or does it really matter because it's all solid-state tech anyway?
Also, have any of you seen converters with built-in level controls? Not cross-overs, but a device that allows volume to the sub to be controlled independently of the rear speakers, which will all be connected to the same channel in this set-up.