I also have the same perfect's but 5 1/4's. I have a soundstream 720 4-channel and infinity 6x9's. Where do you install the x-overs in a Cadillac deville?
I have a Soundstream amp on my Infinity's and I wish I would have waited and bought a better amp. Any place that crossover fits is where you want to mount it, but it should be as close to the speakers as possible. I have mine mounted in the bottom of the door panel, and I just drilled a hole so I could run speaker wire through to the speaker and crossover.