shaun

hey guys i need your help with my hu.
its an older alpine cda-7892 and im having noise come out of my sub rca's.
here is my set up==memphis belle 1300 5 channel amp
2 mb quart comp sets
2 memphis pr 12's and the alpine hu.
the sub outs from the hu have a left and right and the belle only has 1 rca input so im useing the 16-bridge summing box and a set of the matching memphis 5 channel rca's.
im geting a constant rumbleing noise coming from my subs. i tryed switching the sub rca's with another set and it the same thing.
my belle amp has an auto summing feature that if you feed the 4 channel part of the amp a full range signal it will automaticly give the sub side of the amp signal and the bass will play normal just not as loud and the correct way with the 16-bridge and the sub input geting a rca.
all of my wires are fine so only thing im thinking it could be is the hu it self.
and idea's,help or sugestions will really help me out.

imnotplutonium

iTrader: (4)

you checked all of your wires? no cuts or anything? did you run your power on the same side as your rca's? Is your grounding sufficient?

I had a similar problem and it was my ground. It looked good but when I tried a different spot it helped a ton.

shaun

i checked the wires and they seemed fine. the rca's are new and im running 4 ga power and ground wires. the wierd thing is that when i has my hu out last night trying to mess with it i could touch the sub rca with my hand(this is with it connected to the amp) and it would make noise.
also if i has it all wired up and ready to go when i would have my door open it would be fire then when i would shut the door i would get a loud buzzing noise for a few seconds then it would go away. im thinking its the ground but not shure so help me out guys.

KEE AUDIO

iTrader: (65)

Where is your ground for the amp located? In other words what are you using for the ground? I understand you used 4awg wire, which should be sufficient, but what do you have it attached to or screwed into?

shaun

it is attached to the metal piece that the hatch latch(i made a rhyme lmao) mounted with a bolt that was already there. there is grounds on the oposite side of the bracket so i thought it would be ok.

imnotplutonium

iTrader: (4)

yea your sub should make noise if you touch the rca's and it is on. but what doesn't make sense is if you had your head unit out then how was the sub amp on. the remote wire should have indicated 0 volts. guessing you have it hooked up another way or the HU was still on and the rca's were just not plugged in.

I would try a different grounding source. I used the metal on the underneath of the carpet by where the spare tire goes. that worked fine for me and both my amps.

it is weird that your door closing made a buzzing noise. maybe you have a pinched rca around there. where did you run your rca's?

also you did not confirm that you didn't run your power and rca's on the same side of your car. that can cause problems as well.

gnasty1521

iTrader: (7)

These guys make valid points, please make sure they aren't run on the same side and that your ground has good metal to metal contact ( sand the paint off if you have too ) ask me how I know...