myer84

iTrader: (1)

Hey guys,

I got in the car this morning and noticed sound coming out of my subs when I turned on the car. When I turn off the car it makes a loud thump on the subs as the amp shuts off. I checked all of my wiring and everything is connected right. I ran new RCA's and speaker cable to see if that was the issue and I still hear engine noise coming from the subs. I've had my system for a while and never experienced this issue until now. The HU is new and my amp is at least 2 years old. Could it be the amp?

Thanks

dnozzle2789

if you're hearing engine noise with your subs, then im going to assume that you mean engine whine when the rpms go up... if thats the case, then you need to run you're power wire and rca's apart from eachother so they're not close. Or you need to find a new ground... as far as the thump in the subs...it happens to me occasionally, and when i switch songs sometimes too...i was once told what it was, ill try and find out

dnozzle2789

and then im almost postive that the thump is just youre amp turning on and off. no worries if you ask me..it can get annoying though

myer84

iTrader: (1)

Thanks for your replys. Let me give you a little more detail. I've had my system for over two years. I recently (about three weeks ago) finished my new setup. I have had audio install experience for over 4 years and know the basics. I have my power and RCA running seperatly. RCA's run on the passenger side and power on driver side. For the past three weeks my system had been working with no issues until this morning. I really dont hear engine wine on the subs. Its more like a buzz that stays constant and doesn't change its tone when I rev my car. When I shut the car off the thump comes on very loud. Another thing I discovered is that when I play a song the subs dont hit. I can hear and see the subs moving,but at a low volume even though the volume on my stereo is high. Its almost likethe signal is not going through the amp.

dnozzle2789

yeah, it could be the amp, i mean, two years...hm. I was gonna ask you, you have a monoblock amp with the 2 12's...are those subs dual 4 ohm or dual 2 or single...i had a similar problem running my jbl dual 4's off of my jbl monoblock amp. trying to be one ohm stable when monoblock (atleast my amp) cant be one ohm stable, that and a combination with my little battery can't push the power thirsty monoblock..but you have a cap, so im assuming its not the battery..

the buzzing..its in the subs and not the doors?

myer84

iTrader: (1)

The amp is 1200 watts mono running 2 ohms since the subs are dual 2ohms. I couldn't go any lower since my amp only handles up to 1 ohm stable.

There is nothing wrong with the power on my system. Recently bought a yellow top and I have a grounding kit with 0 awg runing from negative post to chasis. The cap is on just for looks. I bought the damm thing before I knew they are not necessary. The digital readout on the cap makes the system look cool. That's why I havn't removed it

dnozzle2789

haha, yeah, i feel the same way about caps...well..that rules out the batt. haha. unless its something ever so simple as reverse polarity somewhere, which with you're experience im sure you would of corrected that right away, im clueless with these details, and my only 2 cents is..amp? try hookin up a diff one for a min, see what happens...? sorry i cant be of much help.. wish you luck on it

myer84

iTrader: (1)

Lol. Thanks for your help. I will take my lil bros amp and see if I'm still facing the same issue. If his amp works with no noise than I know for sure that its my amp that doesn't work anymore.

Anyways if that is the case than I will have to find someone to fix my amp.

dnozzle2789

send back to mtx? or hey,i if it doesnt work anymore, just get 2 smaller mono's :-)

c.mayer

my car was doin the same thing when i first put my amp in and it was caused by a bad ground. As soon as i changed the location of the ground my problem went away

Nycist

+1
find a better ground.

nishfish871

iTrader: (5)

check the rca input maybe you only need one of them in cause it's mono.