distortion?

[Petenick3]

ive recently amped my comps and got a sub in the boot, but i have a problem...
when i turn on the engine a whine starts, which gets louder and higher pitched the more i rev, like its the alternator - but it dont think it is...
could this be distortion from not grounding the amp well enough, or is it something more serious?
it only happens with the engine on though, when its just running on the battery its fine :dontknow:

would love any help!
Pete

[charlton_68]

come on mate, search lol

alternator whine

[Petenick3]

but its really loud, and really annoying, it was never like that before!!
does it mean its on the way out or something?
im not a complete idiot lol i did suspect it but then thought nahh, thts way too loud, people couldnt live with that!

[Coops]

No, it means you earth is crap most likely.

Look in the beginners ICE sticky for info i posted on a good grounding point :thumbs:

[Petenick3]

No, it means you earth is crap most likely.

Look in the beginners ICE sticky for info i posted on a good grounding point :thumbs:

just saw that, its what made me wonder if it was this, i will do this tomorrow, thanks coops :)
oh and your right about the set up of amped comps and sub, sounds great :doublethumbs:
except the bloody whine :lol:

[Coops]

Check all the grounds, including those on the RCA's, the outer sheilding, make sure they are tight and a good contact. :thumbs:

[Petenick3]

Check all the grounds, including those on the RCA's, the outer sheilding, make sure they are tight and a good contact. :thumbs:

quick question; ive seen asked but not answered, how do you ground RCA's?

[Coops]

Honest answer: I dont know :lol:

But ied guess that you would run wire from the outer sheilding of the RCA, the ground, to a ground point on the chasis. This would possibly be done by taking the RCA plug apart and soldering the extra wire in :dontknow: ?

[Petenick3]

ah ok, well ill try grounding the amp well first, then see if i need to ground RCA's, might get away with not needing it done :lol:
cheers

[Petenick3]

i have tried grounding the amp, as coops has said, and the problem is the same - no difference, it only occurs when the engine is on, any other idea's, i havnt tried grounding the RCA's yet, odering it it may be something else as it only happens when engine is on...

[sHq]

It only happens when the engines on, because thats when the alternators on.

[Petenick3]

meaning that its defiantly the grounding yes?

[sHq]

Pretty much yeah.
Are your power and signal cables run down different sides of the car?

[Petenick3]

no, they run down the same...
surely that cant cause it :S ?!

[Mr Nathan]

my two amps are grounded to the seat bolts under that little flap. i get no alternator whine for my sub, but get it from my front comps. and they are both grounded to identical bolts. i also got the whine when it was grounded to the bolt near the boot light....where the rear lights are grounded. i don't know what to do! lol

[Petenick3]

i also only get whine from my comps, not sub, but both come from the same amp....

[Mr Nathan]

where have you grounded the amp?

[Petenick3]

where coops told people to, the hole where you clip you boot carpet too, if you get that... lol

[Mr Nathan]

yea, i know where you mean. mine has done it ever since i installed my comps. i bought a ground loop isolator which was supposed to stop it. it stopped it and it also stopped one of my woofers from working lol

[Petenick3]

hmm, seems to be a bit of a common problem, there must be a way around it, do you think if you soldered it to loadsa areas around the boot then it would be a good enough ground? beacuse theres only a few points where you can bolt it down...

[Petenick3]

bumpety bump

[Gazza_DJ]

my two amps are grounded to the seat bolts under that little flap. i get no alternator whine for my sub, but get it from my front comps. and they are both grounded to identical bolts. i also got the whine when it was grounded to the bolt near the boot light....where the rear lights are grounded. i don't know what to do! lol

That could be because your amps crossover / the frequencies the sub can reproduce are lower than the frequency of the alternator whine ;)

[Mr Nathan]

That could be because your amps crossover / the frequencies the sub can reproduce are lower than the frequency of the alternator whine ;)

i don't understand a word of that but what can i do about it? I have Rainbow Deluxe Components amped by a JBL 75.2.

[mike_s]

no, they run down the same...
surely that cant cause it :S ?!

Causes lots of interference having the batt wire and signal wire running down the same side

[Gazza_DJ]

i don't understand a word of that but what can i do about it? I have Rainbow Deluxe Components amped by a JBL 75.2.

Basically, your sub can produce frequencies of up to a certain amount. For arguements sake, lets say 400Hz. the crossover basically only allows frequencies below a certain amount through, for arguements sake lets say yours is set to 250Hz. If the frequency of the alternator whine is above 400Hz (which im pretty sure it is) then the sound will not be heard for two reasons - the sub cannot produce frequencies above 400Hz, and your crossover isnt letting any frequencies through above 250Hz.

As said in the thread, it is most likely a grounding issue and / or where you are running your cables!

[Mr Nathan]

Basically, your sub can produce frequencies of up to a certain amount. For arguements sake, lets say 400Hz. the crossover basically only allows frequencies below a certain amount through, for arguements sake lets say yours is set to 250Hz. If the frequency of the alternator whine is above 400Hz (which im pretty sure it is) then the sound will not be heard for two reasons - the sub cannot produce frequencies above 400Hz, and your crossover isnt letting any frequencies through above 250Hz.

As said in the thread, it is most likely a grounding issue and / or where you are running your cables!

i think this is the issue lol

[Gazza_DJ]

where are they running? Its always a good idea to have audio cables and power cables running down separate sides of the car, and never have them meeting. If you have no choice and they have to cross paths, make sure you have them crossing perpendicular to each other.

[Coops]

I cant see why some people get so many problems tbh, ive never once had alternator whine in my two installs :dontknow:

[Mr Nathan]

yea i didn't realise you weren't supposed to have them running down the same side and i have my power running down the same side as rcas. i will change it over the summer and see if it solves the problem. is it possible to have the power cable running down the center? how do i go about getting under the center of the car?

[Coops]

yea i didn't realise you weren't supposed to have them running down the same side and i have my power running down the same side as rcas. i will change it over the summer and see if it solves the problem. is it possible to have the power cable running down the center? how do i go about getting under the center of the car?
You have to remove both seats iirc

[jacko103]

yea i didn't realise you weren't supposed to have them running down the same side and i have my power running down the same side as rcas. i will change it over the summer and see if it solves the problem. is it possible to have the power cable running down the center? how do i go about getting under the center of the car?

power - rca interference should not occur. We are talking DC current and shielded cables.

[sHq]

Well wouldn't the DC power cables pick up the noice interference from the alternator?

[charlton_68]

I cant see why some people get so many problems tbh, ive never once had alternator whine in my two installs :dontknow:

your a pro though mate :lol:

I still get alternator whine since grounding in the place you suggested. My cables are all seperated too, well I think they are. How far do they need to be seperated??

[Coops]

your a pro though mate :lol:

I still get alternator whine since grounding in the place you suggested. My cables are all seperated too, well I think they are. How far do they need to be seperated??
My cables cross over under the rear seats where theres excess wire which i have yet to trim down so i wouldnt of thought that would be the problem.

I have heard that manually grounding the HU can help? Might be worth a try?

[Petenick3]

what about grounding to the back of the headunit as well as the boot area?, then it has a direct wired earthing point? or will this be bad?

[charlton_68]

My cables cross over under the rear seats where theres excess wire which i have yet to trim down so i wouldnt of thought that would be the problem.

I have heard that manually grounding the HU can help? Might be worth a try?

How would I manually ground the HU mate? Be as simple as possible :D :lol:

[Coops]

Dont quote me on this mate, but ied cut into the earth wire on the HU loom and solidly earth it somewhere behind the HU.

Might be worth doing a bit of research on solving alternator whine on here first...

http://www.talkaudio.co.uk/vbb/index.php

As ive never had the problem ive ever really taken much interest in learning about it. Im sure i read about grounding the HU somewhere though :dontknow:

[figo_rulz11]

thinking of it like a supercharger whine :lol:?

[Petenick3]

had a quick search and alot of people say that, and also get similar features such as a pop when turning off headunit, and glitches when changing volume, so ill try grounding the headunit sometime and see iff that cures it..

[charlton_68]

Dont quote me on this mate, but ied cut into the earth wire on the HU loom and solidly earth it somewhere behind the HU.

Might be worth doing a bit of research on solving alternator whine on here first...

http://www.talkaudio.co.uk/vbb/index.php

As ive never had the problem ive ever really taken much interest in learning about it. Im sure i read about grounding the HU somewhere though :dontknow:

cheers mate. i might have a go if a get a spare few hours one day :)

[Coops]

No problems bud, let me know how it goes :thumbs: