I have a 1999 Jeep Grand Cherokee that I took out the stock Infinity sound system and replaces with Rockford amps and Boston Acoustic 6.5 Pros in the front (receiver and other speakers upgraded too, but irrelevent). I reused the stock wiring, since it matched what I was putting in for speakers (component fronts, coaxial rears). For some reason, I can't get my front door speakers to go below somewhere around 100hz, even when I have my amp set for full-pass. Rear speakers off the same amp are responsive to the amp's crossover. I've tried swapping the channels on the amp to ensure it's not the amp in any way, and the rears are also responsive to the crossover that the fronts should be using. The wiring is correct (no phase issue). I'm wondering if with the stock wiring of the Infinity upgrade, that there is a passive crossover on the front door speakers somewhere down the wire between the amp and the speaker connector, because that's the symptom I'm having. I couldn't find one with my searching, but I haven't ripped any carpet up. The tweeters work fine, and give a flat curve into the woofers. Just no mid-bass out of the door speakers. Can anyone advise on if my guess that there is a passive crossover on the front door speakers is correct, and if so where they're located so I can bypass them?
the wiring for the speakers shouldn't be a problem. The Infinity setup had the driver in the door only play I think 200hz and down. I don't remember though if the crossover used was a passive or active at the amp. I thought it was at the amp. You may want to check your HU's settings as far as HPF and all.
I used the stock wiring in my 99 jeep when I had it and about 4 months later, I lost the left channel. I ran a new wire into the door to bypass the stock leads and the problem was solved. Dont use the stock wiring.
A funny thing, gains can be. When I moved my system from my Mustang to my Jeep, I upgraded my HU at the same time. My new HU has 4V preamps, so my RF amps were able to push out max volume without distortion with the gains set all the way down (as opposed to 2/3 up with my old HU). However, when I put the gains at 1/2 and just gave the signal less volume from the HU itself, I was (obviously) still able to hit max clean volume, but my front woofers woke up. I'm not sure how much sense this makes, as I always thought of the gains as the equivalent of a volume knob, maybe I've been wrong. Does it have something to do with the efficiency of the tweater vs. the woofer, or maybe something with the BA x-over? Regardless, the problem is solved, and everything sounds great even with the stock wiring (even if there is a stock x-over, they're so low that they don't interfere with high-end component x-over points).