my sub makes noise with car off

[mrray13 10+ year member]

i have a 12" boston generator sub in my wifes car w/ a legacy la320 amp(i know they ****) and crossover. the factory cd hu is still in the car. my problem is that whenever i turn the car off and pop the trunk the sub hums REAL loud. i've disconnected the remote turn on and that helped some. the input level on the crossover is almost all the way off and that too helped. i have the amp grounded at the trunk latch. could that be it? the sub don't hum with the trunk closed or all the way open. sorry about this book, but i'm stumpped!

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[<natem33>]

If your ground is connected to the latch and opening and closing the latch corrects/alters the humming then I would deffinately try to re-ground the amp. When I have experienced that type of humming I have found the problem to be with the connection of the audio signal. This could either be the RCA plug connections (if you are using one) or the line level input connection on the amp. Trouble shooting with the different connections should reveal the problem. If the problem is not found within the connections it may be the amp itself. When an amp has internal problems, it sometimes can result in noise being created while the amp is off. I suspect the it's a connection problem though.

 

[<jon>]

all i can think of is tryin to wire a switch to the remote wire if that doesnt work than i dont know wha the hell is up with it

 

[ramos 5,000+ posts]

I would try grounding the amp soemwhere else. See if that helps. How do you have the amp connected to the deck ? Are you using speaker level inputs, or are you using a line output converter ?

 

[mrray13 10+ year member]

i'm using a line out converter off the rear speakers.i've tried two different crossovers, the one i'm using now doesn't do it as bad,however, the right channel doesn't work with either. and that's on the input side. could that have something to do w/it? hopefully soon a new h/u and amp are on their way in. then i'll use rca's down the other side of the car. this noise isn't going to hurt the sub is it? i got a three year warranty on the sub but i'd rather not use it if possible.

 

[ramos 5,000+ posts]

quote:



Originally posted by mrray13:
i'm using a line out converter off the rear speakers.i've tried two different crossovers, the one i'm using now doesn't do it as bad,however, the right channel doesn't work with either. and that's on the input side. could that have something to do w/it? hopefully soon a new h/u and amp are on their way in. then i'll use rca's down the other side of the car. this noise isn't going to hurt the sub is it? i got a three year warranty on the sub but i'd rather not use it if possible.





It very well could have something to do with it. Have you tried moving your ground to see if that helps ?

 

[mrray13 10+ year member]

haven't had time yet. i'll probably do it this weekend. then i'll let u know if it worked. where would be a good place to put the ground? it's in a 98 mazda 626.//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[ramos 5,000+ posts]

If you have any kind of seat bolt or anything close I would try that.

 

[mrray13 10+ year member]

here is a new twist to the story. i took the rcas straight from the l.o.c. to the amp and the hum was really bad. i then reconnected the crossover and turned the gain all the way up. same result. all this with the car off and the trunk open. what next? i haven't moved the ground yet because her car is a bi@#$ to take apart and put together. also the amp is constantly on( no remote because of factory stereo and no power antenna). and now the best part, w/car off u can tap anything in the trunk and hear it in the sub. the floor, wall seat,anything and you can hear it in the sub. what am i doing wrong?

//content.invisioncic.com/y282845/emoticons/mad.gif.c18f003ab0ef8a0d9c27ca78d77a6392.gif//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[MxRacerCam 10+ year member]

eeks! that does not sound good at all does it?? there are three main problem areas with your install....

1) the amp is always on. i'm surprised her battery hasn't gone dead yet! move the turn on lead to a switched power source at least (i.e. the fuse panel)

2) the ground the ground the ground //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif attach it to something else... and try to make sure the metal is bare at the contact point for the ground. it's humming because there's an open loop whenver the latch isn't in contact with the base. when it's fully opened or closed, it is resting on the stops, and therefore in contact with what is presumably a better chassis ground. so if you haven't gotten the point that everyone else has been saying repeatedly... move the ground!!!!

3) the ground.... yeah, it's on here twice.... get the point?? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[mrray13 10+ year member]

ok say i've moved the ground(will do sunday) won't hooking up the remote to just a fuse(it was to her p.w.) cause feedback? also a real "thump" when turned on? i'm not worried about the battery,her cars' computer will make sure the battery don't go dead(shuts everything off except the puter w/excess battery drain).

 

[bean 10+ year member]

Dude, don't be stupid. If you don't hook up your amp to a remote turn on you will damage something. Turning everything in the car off except the amp will still cause your battery to fail. Once your battery dies (and it will) you will never ever ever be able to get it to perform like it should. It doesn't sound like you're having much success in doing anything anyone else has suggested to you. It also sounds as though you don't have the time or the correct tools to take apart the car. My advice to you would be to take it to a professional and have them do it for you. It may cost you $75 bucks or so, but you gotta think........YOU aren't having any success and those guys do this for a living. In the long run you'll save yourself a ton of time and probably some money.

P.S. Your car isn't that tough to work on. Please take it to a professional.

bean

 

[mrray13 10+ year member]

hey bean, guess what? i'm not stupid!//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif ALLRRIIIGGGGHHHHTT!!!!!//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

but seriosly the problem is fixed.(done today) moved the ground and did a little re-wiring. hooked the remote back up(switchable ignition wire) and shorttened a lot of wire.

next week a new rf 120.2 power punch amp goes in!!

THNX to all for the help!