12-30-2010, 01:05 PM
Join Date: Oct 2010
Speakers Thump when power is turned off.
I know this a common problem with aftermarket amps. (been searching the net on many forums). If it is common, then there must be a common solution. I just haven't found it yet.
I have a Sony amp model GTX-6040. 4 ch with 60w RMS per channel.
I'm running it as a 3 ch. Left and right speaker high level inputs to 2 ch and the other 2 ch are bridged to power the subs.
Sounds great blah, blah, blah. No use going into that. It works well and now onto the problem.
It does not thump when started up, it thumps only when I turn the car off (not a Jeep).
The amp has a input sensing power on which works well with the speaker level inputs.
Yesterday I hooked up the remote power on blue wire to a switched source via the ignition key to see if that would cure it. It still thumps.
Is there a capacitor circuit I can add to the speakers or something?
It is all speakers hooked to it that thump, not just the subs. (Two 6x9's and two 10" subs). All 3 thump.
I figure the first thing you will say is to not use the speaker level inputs.
This is on a factory head unit with Sync, Satelite radio, steering wheel controls, voice commands etc. Replacing the HU is not going to happen.
I saw a couple devices you hook into the speaker wires to give you RCA outputs, but do they work? Is that really the problem?
I've heard of speaker thump from other people and they have RCA inputs...
What can I do to correct this other than "buy another amp" ?
Some things I already tried was re-route ground to another spot of chassis. Add other ground. Move speaker wires away from power wires and ground.
(when I installed the system I ran all new wires and used true US 4 gage wire, looks like a battery cable running to the amp. Also has 4 gage ground).