I want to warn you about this, It is a low cost amp, and by that I mean not worth your time. I ran a test today and had thermal issue at the following volumes at these gain settings (RCA) via LOC input and ~17.9 volts out, do the math, 4 channels and a sub, no where near 1800 watts. Planet Audio said "We are here to assist you with any problems you are having with any of our porducts. It's very strange that you are having this issue with the amplfier. It seems that you have everything connected correctly and there is just an internal problem with unit. The unit can be sent in to us so that we could investigate the issue and repair the unit. I would need a copy of the purchase receipt so that i could process an RA." This is going on 2 weeks and still no contact about an RA number. Money is well spent on something else that might eliminate the frustration of money spent on a low quailty product. 1. Car volume goes from 1 – 30 and I figure 75% is 23 a. Volume set to 23 will thermal trip at 45 minutes, then not again because I get to work and the temperature is cooler. b. Volume set to 18 will thermal trip at 20 minutes, Car sits in the sun and gets hot during the day. c. Volume set to 15 will thermal trip at 15 minutes after the 1st reset. c. Volume set to 12 will thermal trip at 10 minutes after the 2nd reset, it is already real hot. Volume set to 10 will not thermal trip at 10 minutes after the 3rd reset. Not sure if would because at this point I’m home or the volume has been dropped to 10, or 33% of the available volume.