Alright, here is my situation. I have a 10" eclipse aluminum sub that i purchased and went through a long process of making a fiberglass box that would fit perfectly to the trunk, long story short the box i came out with was WAY to big. I couldnt run even a 250.1 rockford to it without it seeming to cut out. I noticed taht 1 day i heard it go on and off, I pulled over and saw that the sub was "hitting" as in moving air, but no sound, and it seemed that it was having a hard time, so I immediately pulled my fuse and drove home. Well, i spent the time and made a 1.2 cubic foot box, just about the right size and put the sub in. I have it wired for 2 ohms, it is a dual 4 ohm voice coil. So, i reconnect the fuse after hooking up the sub and nothing happens with the sub. The lights in my car seemed to dim when the music hit a little. The amp is a sony xplod 1600 watt max 900 watt rms amp, it showed green and then about 3 seconds later it went to a red color. Showing that it was in protection mode. Evene when it wasnt the sub didnt hit, at all. I checked my wiring and i think its right. Also, when I turn off my key I get a noise from my rear speakers, not really a musical noise, just a feedback type noise that is pretty loud. I need some help. My system(right now) is as follows: 4 gauge from the battery then split into 2 8 guage wires with monster cable distribution block. Those 2 8 gauge wires go to 1 kenwood 600 watt amp and 1 sony xplod 1600 watt amp. The deck sends power to diamond m3 coaxials int eh front and stock speakers in the rear doors. In the rear deck are 2 alpine type R 6.5" speakers powered by the kenwood amp. Powered by the sony is 1 10" eclipse aluminum. Each amp has its own ground, i ran the remote wire directly to the kenwood and spliced it to go to the sony as well. Well i think thats about it. Anyone have suggestions?

 

You might also try to hook booth aps to the same ground location, to try to isolate engine noise. I agree with justgo, the sony XMD-1000P5 amp that you are describing has givin me and my few customers that bought it grief. If you are still within your return policy with the company you bought it from i recomend exchanging it for something else. You have a realy nice sub, retails for over 300 bucks, and a crapy amp, 200 bucks. Not a good match up man. Usally you will want to spend more on your amp than your spkrs. Unless you are me. hehe

Mike @ Magnolia Audio Video