WTF's going on

[filthy one]

Help me or i'll burn it !!

I changed head units in my pontiac but sinse doing it {using the same power earth wires etc} its all good untill i start the car then the sound pulses with the car. Sub works fine but speakers shut down altogether after a few secs.

I tried 3 alt head units & even wired it direct to the battery but it still does it AAAARRRRRRRRRRRRRRRGGGGGGGGGGGHHHHHHHHHHHHHH is it simply a noise suppressor I need due to the beast being old . Im confused cos I never had one before it had a sony xplod head unit in there that worked fine i changed it to Kenwood & tried a pioneer one too {cant try the sony one again cos I sold it } maybe the sony one had a inbuit suppressor & the others dont ??

Fucked if I know but man i'm getting FUCKEN FRUSTRAITED now

[Beaver]

maybe alternator is playing up? creating fucked up supply. im assuming subs are stopping due to amp switching itself off which would mean power spike or something like that?

[tortron]

sounds like you need to check your grounds and get a ground loop isolator

[RUNAMUCK]

Maybe check your voltage while the head untis playing up with a multi meter and see if maybe you have an alternator fault?

[filthy one]

sub & amp keep on runnign sweet .. Get this i just took the battery out of my work ute sat it on the floor in the front of the car hook up power & earth to it so it eliminated the car power source completely but it still fucken does it aaaarrrrrrrrrrrrggggggggggggggg even going hooking up ony 1 speaker it does it to what ever one it is so its not one random etc

MAn I cant work it out

[UTERUS]

I had this problem with the pioneer head unit i have.

I had blown a fusible link for one of the earth tracks on the circuit board, it was then using the earth via rca sheild for the speakers.

I took it all apart and located the bung link and soldered over it, i wouldn't reccomend you do this unless you are used to working with fiddly circuit boards.

If you do feel like having a look inside, it isn't obvious obvious which is fucked and you will need a multimeter to check all the tiny fusible links.

Try searching the model number or even the make of the head unit to see if anyone has had this problem before?

Post up the model anyway and i'll see what i can find

[Yowzer]

Probably a high frequency buzz from alternator, the sub amp will have a built in crossover that will eliminate it but the speaker amp will be getting full noise.

Usually it'll be coming through the head unit, but if yours was running on a separate power source from the amp, there's the probability of a ground loop issue.

Ignoring that however, maybe the noise suppressor on your alternator is fucked out. Generally just a cap of some sort.

All your RCA cables in good condition? If the outer earth on them has a problem then that will fuck shit up

What sort of sound comes from the speakers? Whine that increases in pitch with engine speed? Or something else?

[filthy one]

Probably a high frequency buzz from alternator, the sub amp will have a built in crossover that will eliminate it but the speaker amp will be getting full noise.

Usually it'll be coming through the head unit, but if yours was running on a separate power source from the amp, there's the probability of a ground loop issue.

Ignoring that however, maybe the noise suppressor on your alternator is fucked out. Generally just a cap of some sort.

All your RCA cables in good condition? If the outer earth on them has a problem then that will fuck shit up

What sort of sound comes from the speakers? Whine that increases in pitch with engine speed? Or something else?

just makes the song playing cut out but it goes with the pulse of the engine etc even disconnecting the amp & sub & using the sererate battery from the one in the car it still does it so this would rule out my alternator causing it i think cos im not using anypower source from the car itself the radio cradle will be earthing on the dash so unless is got some kind of short form the tacho wire on the body which would cause the dash to have a slight power pulse running back through the earth

Far out does that even makes sense

I've tried 3 alternative head units now so it eliminates it being a faulty one

[UTERUS]

Golly, sounds epic to make a song cut out. Ignore what i said previously then.

When does the music cut out?

Are there any speaker terminals or cable touching the body? Maybe when the speaker starts cranking it vibrates its steez onto metal and cuts the music.

Is it all operational and problem free with the motor not running?

[mikuni]

I think its simply earth related. Something the lines of a poor earth creating eddy currents that run through the body of the car. I guess the reason these change with revs is because of the increase in current flow. It will probably still happen regardless of power source though.

I would check how you are earthing the head unit, how the engine is earthed and the main earth to your battery. Preferably keep them close to each other if possible or just add some. A jumper lead can be used to test this solution before splasing out on a $400 hks earthing kit for max powah

[bubblegoose]

Maybe when the speaker starts cranking it vibrates its steez onto metal and cuts the music.

THIS^ happened in my french turdo

the speaker wire hung down onto the back of the cone and got bounced out to the speaker frame

over time it wore off the insulator and make my head unit cut out untill wire moved off frame

took me weeks to figure it out

i also had issues with unsuppressed ignition system playing EMP spec ping pong with my entire sound system, that was painful (5555W of paint fyi) but sounds similar to your issue also

[UTERUS]

I think its simply earth related. Something the lines of a poor earth creating eddy currents that run through the body of the car. I guess the reason these change with revs is because of the increase in current flow. It will probably still happen regardless of power source though.

I would check how you are earthing the head unit, how the engine is earthed and the main earth to your battery. Preferably keep them close to each other if possible or just add some. A jumper lead can be used to test this solution before splasing out on a $400 hks earthing kit for max powah

Kinda right, there is always current flow through the body/engine/chassis anyway so some rouge current from a device will just absorb itself with the others.

HOWEVER, that crap that you hear through the speakers is not 'eddy currents' it will be an ac voltage or rippling dc.

It will change with engine revolutions because the higher the engine speed, the higher the frequency of the rouge voltage.

Still, that won't shut down the amp inside the head unit. So i still put money on a speaker cable/rca/speaker touching metal

[filthy one]

Thanks for a your helps fellas i to thought it must be speaker or amp cable but it disconnected the amp for the head unit rca & power supplies still did it. Then went unhooked aqll speakder for the head unit hooked up them up one at a time thibking if one was earthing out the 3 that were not should still be sweet but nope all 4 cut out the same ..

Its only when the cars running its all fine when the engines off & just to make it worse even with the head unit on the carpet floor of the car not touching any metal & only the power & earth from an outside battery source & 4 unamped speakers hooked up IT STILL FUCKEN DOES IT !!!!!!!!!!!!!!!!!!!