I've owned 2 of the LI 15's and ran them off of the SAZ-1500D with a Deka 9A31 secondary battery. I had the big 3 upgrade with 1/0 wire, on a stock 110amp alt with minimal dimming at maximum listening level. This was with accesories going (headlights, air conditioner). In my opinion the Sundown is just a nasty amp for the money...my .02