Hi all, somthing odd started to happen, when i turn my HU on i now get a real "thump" from the sub.

Dosn't matter what level the sound is at, even turned to 0 or paused i always get a big ole thump from the sub, never used to do it :0)

Any ideas?

Btw: its a Vibe 12" black air box with the amp fitted to the box, connected via a quick plug so i can take it out easy. Alpine HU.

Does the sub power off when you turn the HU off? It may be that the remote output on teh HU is giving out power permanently for some reason..

yarp, had a look at the connections to make sure everything is ok, the amp powers down about 10 or so seconds after turning the HU off, guess thats the capacitors.

If i turn the HU on after the car has been sat all night then it thumps, and also if i turn off and then straight back on it does it too.

Does it still do it if you disconnect the phono leads from the back of the HU? Could be a problem with the soft start circuit in the amp.

Does it still do it if you disconnect the phono leads from the back of the HU? Could be a problem with the soft start circuit in the amp.

ahh didnt try that, i'll try it in the morning when i go to work.

EDIT: ok i turned the gain down a little and it seems ok now, tried removing the RCA but didnt change it. As i understand it the gain affects the incoming signal from the RCA leads?

Edited 19 August, 201015 yr by RichieB75