Startup Thump

[vipervin 10+ year member]

when i startup my car, the subs annoyingly thump. i am pretty sure its the sub amp cuz 1) its old, and 2) my newer component amp doesnt thump.

aside from getting a new amp, is there anything i can do about the thump? does the thump cause any subwoofer damage? .. cause it sounds like the sub is momentarily crying for help //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

Click to read more...

 

[blackbonnie 5,000+ posts]

its a ground issue, make sure your grounds are secure, connected tightly, and its getting bare metal to metal contact

 

[mdillon 10+ year member]

some old amps do this. you could run a toggle switch on the remote wire so you can turn it on and off when desired or live with the noise

 

[Pl8er 5,000+ posts]

Did you take all of your grounds wrap them around each other and secure them to one point on the car?

This is the most common reason for the "thump"

Remove the ground, sand off the paint at the ground point or move the ground to a new location.

If the grounds are all together, try seperating them.

 

[Johnny Drama 5,000+ posts]

Do what Pl8er says if that doesnt work try not to use your remote wire off the deck. Try useing a relay for turn on and off...might help.

 

[vipervin 10+ year member]

my ground is good as it gets. its sharing the ground point with my component amp.

i will try separating the grounds and see if that works.

jntar- would i be able to use the remote wire from my HU to the component amp, and then from the component amp to a relay to my sub amp?

HU ---> Component Amp ---> relay ---> sub amp

OR

HU ---> relay ---> component amp and ---> sub amp

 

[Johnny Drama 5,000+ posts]

my ground is good as it gets. its sharing the ground point with my component amp.
i will try separating the grounds and see if that works.

jntar- would i be able to use the remote wire from my HU to the component amp, and then from the component amp to a relay to my sub amp?

HU ---> Component Amp ---> relay ---> sub amp

OR

HU ---> relay ---> component amp and ---> sub amp

I would do the one I bolded...or you could even tap into another source like ignition.

HU

Relay

Comp and sub amp

 

[jrwalte 10+ year member]

It may be noise getting through your HU and traveling along your RCA to your sub amp.

Try disconnecting your RCAs from your sub amp and turn your stereo on (volume off). Turn the sensitivity (gain) of your amp up and start your car. Do you hear a thump or alot of noise? With the gain turned up you should expect some noise...but you shouldn't hear your car revving. If not, you have a good sub amp ground. The issue is either coming from your HU or your RCA.

Turn off power reconnect RCAs and pull out your HU to disconnect the RCAs from it. Turn stereo on. Any thump or noise? If not, it is your HU causing the problem.

Possible HU issues can be:

Antenna - disconnect to test

ground - try creating your own ground to the chassis

deffective - something internally in your HU may have screwed up and it needs to be serviced.

 

[J31Rob 5,000+ posts]

old amps have no soft turn on.

 

[snoopdan 5,000+ posts]

you can buy a thump-on eliminator

http://www.sonicelectronix.com/item_11478_SoundGate+TRIGDLYA.html