View Full Version : Thump when system turns on, turns off, and when selecting sources.

03-11-2012, 09:29 PM
I recently added a Kicker ZX 750.1 to my system to power a single JL 10W3. Im running it in 4ohm to the single sub. There is also a JL 300/4 running my mids/highs... and before the kicker amp the 300/4 ran the whole system including my sub. Never had this issue before.

I just installed the amp... and ran a new RCA from front to back to the Kicker amp. Ive noticed I get a loud thump from the sub when turning on, turning off, and also when switching from CD - line in - radio - etc. Each source produces the thump.

Ive read up online so I have some things to check but thought Id ask here in the meantime.

Couple things... the new RCA isnt the greatest of quality. The remote turn on is routed right next to the Kicker amps power wire, literally on top of it.

Oh also... the amp has a feature to turn on by 12v remote, DC power from the 12v in, and also RCA input. It does this with all 3 settings.


03-11-2012, 09:45 PM
what head unit?

the noise from turning on would be because the amp turns on too soon, before the source...but it sounds like a different problem, psooibly related to the order in which things are turning on or off

try disconnecting the 12v trigger and turning the amp on my manually touching a wire from the fat +12v to the remote trigger AFTER EVERYTHING ELSE IS ON

but that's a strange problem with it making a noise when switching sources

03-13-2012, 12:44 AM
little off topic but how does ur w3 sound in ur car

03-13-2012, 12:49 AM
Things to do....
Check all your grounds. They should be to bare metal, and short as possible. HU ground should not be using the factory ground. Ground it to the dash frame.
RCAs should not be ran next to your power wires.
If that doesnt work, ground your RCAs to the chassis of your HU.

If all that doesnt work, use a ground loop isolator.
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03-13-2012, 02:47 PM
Caliboy... this is actually in my truck. Sounds pretty good in my truck, I bet it would sound even better in my F-body back in the t-top well.

jonnyv.... thanks for the input. Im going to try to re-route everything. I do have some wires closer together than Id like them to be.

03-13-2012, 04:16 PM
oh ok just wondering. i bought myself a used jl stealthbox with 1 10 w3 but the sub is blown. i dont know if i should get something else or stick with the new version of the w3