Sub Goes Boom!

as soon as the head unit gets power going to the amps the subs before any music is played give a really hard thump, its not long, just one huge thump. Is it due to a bad ground on the amplifier, bad turn on lead, is the amplifier just bad?? or could it be rca cables going into the amp, the amp wasnt installed by me and I was just wondering what the problem could be first without me having to pull the drivers seat out. Any help is appreciated, thanks.

I ahd this problem with my sub after I had a line level convertor with the stock HU then went to an alpine. Circuit City installed everythign for me and then I went back the next day becasue of that and the guy had to redo a wire behind the headunit, I'm not sure which one maybe the remote turn on?

I thought this was normal? My brothers does this, always has. mine don't thump tho

nah it aint normal, this is in a friends car and my car does not do this at all.....ccloritz he did have a line level that was being run off of his rear speakers to the subwoofers......its freakin loud, you will feel the thump 10 feet away.....ill check the back of the head unit when i get a chance.......thanks

any other suggestions?

[ptrudel]

all 4-5 brands of subs/amps and decks (different combinations too) have always done this...it's not as bad as u describe it tho...mine really goes nuts when my cell phone is about to ring...

[BLK03GXS]

Some amps and decks dont have a remote power on delay.. thats why your getting the problem you have...
maybe if you used a relay to remote turn on the amp it could solve it... but i doubt it...
Allso make sure that whoever installed it didnt use the ant remote led... have to use the remote led...

[sound_xtreme]

yea, ALL amps(that dont have a soft turn on feature, which most name brands do have it) will do this when the gains are turned up.

I have had 3 cars with 3 different subs and 3 different amps, and i have neer had turn on or turn off thump.

I would just make sure all your connections on the amp is good...

What size/kind of wiring are you using? Good stuff? Are your RCA's ran next to your power?

[AleroHawk]

You have to look at the specs of the amp. If it has mute turn on/off cicuitry (also known as soft turn on/off as sound_xtreme said) it won't thump when the HU is turned on/off. But if it doesn't have it you will definately hear the thump.

thanks guys for the help, the person who hooked up the first amp hooked it up a +12 volt source, so as soon as the key turned, so did the amp......Fixed that crap.....i tell you what......this dudes got alpine type r speakers all the way around, with the 12 type r's in the back run off all alpine amps........it plays so loud and clean, makes me want to upgrade mine lol......I definately will be getting 12's and most likely those alpines are a possibility, they sound awesome

[xsavyor1]

sometimes you will get a ground loop noise witch will give you that pop. Try making your ground line shorter. or longer it sometimes helps.