i ended up adding a secondary battery on my '02 suburban. it is a stinger 680 (if i remember correctly.) Very small, but very effective. No lights dimming anymore, and it seems like the system has less trouble with very low notes now. I currently have a Memphis PR1000.1 running 2 MTX 7500 12's. I will be adding a PR50.4 soon as well. Before I added the battery, when pushing the system I could actually watch the voltage gauge fluctuate from 14 down to 12.5-13 or so. Now it is rock solid.