Yeah, so... The sub is blown anyway. The cone has separated from the rubber. I suppose I could try a repair (glue/kits) but
the back seat has to be removed to remove the subwoofer, so I am just going to replace it. It's also a 14-ohm sub, so the head unit was going to have trouble anyway. I will be looking at replacement amps too, so I am not sure yet which way I will go, but I am thinking of going with:
- Reuse current spare head unit (can be upgraded later if needed)
- Buy replacement free air 10" sub with DVC
- Buy a 4 channel amp with ability to use high-level/speaker inputs
- 3 way crossover for the front amp output for highs (front A pillar tweeters), mids (front door), lows (rear sub)
- Rear amp output to the read door speaks with a high pass filter (separate or from amp)
- Reuse existing door speakers (can be upgraded later if needed)
This would mean that the only parts of the factory system not being used are the center dash speaker and front door speakers not getting highs. As mentioned previously, the later sounds better with highs at the pillar tweeters instead of the door speakers (if I had to choose one and I can't come up with a cheap/easy solution to use both). As to the center dash speaker, I could look to a two-way cross for the rears and bridge the highs to the center dash speaker. I am guessing that would sound better for the driver and we rarely have anyone in the back anyway. The DVC sub would keep the ohm load balanced between the left and right amp channels and that would be the only wiring I would run (speaker wire from trunk amp to rear-deck mounted sub).
I can also just ignore the read door speakers and bridge the rear amp channel to the sub. Or possibly power them from the head-unit directly.
I big issue for me is cabling (and/or my laziness to run cable). I need 9 lines running from the head unit to the back (8 for the 4 channels, 1 for remote turn on), which I should already have in place by reusing the factory cabling. But what I don't have are RCA cables. In theory I should be able to solder RCA jacks on to the copper wire already in place to take advantage of the low-level outs from the head unit, correct? If not, then I would just need an amp that accepted speaker outputs as inputs.
By keeping the power in check I should be fine with the existing power runs that are already in place. The old sub had two 12V inputs but the wiring is like 16 gauge. I think I should be able to tie them together for a little added safety prior to feeding them into the new amp but it is something I need to check.
I will also look at 4.1 channel amps too, but I will probably need to run new power lines for a 4.1. The in-place 12v lines running to the amp have 30amp fuses and 4.1 amps need more power. And the subwoofer is just an open-air rear deck mount, so the sub power needs to be kept in check anyway if it is not in an enclosure (IIRC). I can always replace the 4 door speakers if I need to in the future. And the head unit too.