I have a 2006 cobalt and decided to upgrade the stereo system. HU is last on the list, so for now, I bought an amp and a sub. The amp is a 4 channel amp with 75 watt RMS per channel. I've got the left and right speaker inputs from the 6x9 spliced in such a way that they power both channels 1 & 2 (one high level input on the amp) and 3 & 4 (second high level input on the amp) So basically, 2 channels from the HU are powering 4 channels on the amp.
From there, I've got channels 1&2 bridged going to the sub (150 watt RMS, sub is rated for 175 watt RMS). Channels 3 & 4 go to the original 6x9 speakers. The system sounds great and I can see no ill effects on the car (yet), but I'm wondering if I'm doing something I shouldn't be with respect to the wiring.
