Solved! Loud Humming coming from Sub

[nexuscustoms15]

So i have a car sub hooked up in my house. I know everything works fine as i tested it all with a car battery and it sounds incredible. But i dont want to keep a car battery in my house so I bought a computer power supply that out puts 30 amps @ 12v (that is what my subwoofer amp is rated for).Once i connected that, all i'm getting is a Hum. I've tried connecting the power supply to different outlets in my house but still a loud hum, that does not help. The only thing that makes the humming go away is disconnecting the RCA cables. I have 3 stereos all in the same general area of the amp and power supply. The RCA cables that connect to the amp output through one of my stereo recievers. I believe this is a ground loop within the power supply, but i just found it odd how the humming stops when there is no RCA input connected. Any ideas on what exactly my issue is? and how to prevent it. "Dont use car subs inside a home" i can expect to see that reply and i understand but i got a $300 amp for $50 and $100 subs for $30 with a bit of bargaining so i would not like to switch my setup as this was an amazing deal. Any help is greatly appreciated. HOW DO I STOP THIS HUMMING!?!

 

[americanaudiophile]

You do have a ground loop but not "within" the power supply.
The power supply has a three prong AC plug and so does the receiver. The RCA cable also makes a ground connection through the subwoofer amp to the power supply. You will find that many powered subwoofers only have two prong AC cord to eliminate this ground loop.
You can use a ground lifter to break the AC ground or an audio isolation transformer in the subwoofer cable to break the loop.
http/web.mit.edu/~jhawk/tmp/p/EST016_Ground_Loops_handout.pdf