Car Stereo Issue...

In my automobile, I have a fairly decent and elaborate sounds system. Its nothing to brag about, but sure as heck not the stock unit. Therefore I take pride in knowing that what I hear coming from the component speakers is good, or should be. Recently though, an extremely annoying sound has begun to unwind. As you are driving, you can hear the annoying high pitch hum of the engine. So as the engines RPMs go higher, the pitch of the sound does the same. Many cars do this, but I hate it, and cant stand hearing it.

I know its from two wires coming into contact or close proximity. One being the cars electrical wire of some sort, and likely a power cable for the head unit (Alpine). From there though, I know little to nothing. I have moved around some wires that are under the hood (the main power cables to the amplifiers) with no luck at all. Being that it just started, it makes me think that its a cable that moved into a non great position. Any car audio buffs here that know where I should start and begin looking for the reason to such an issue? Thanks,

-Cameron

loose ground,or bad battery or alternator with bad diodes in one phase.
often that engine rpm dependant whine is the first sign of impending alt/batt death.

This has been a while for me "years" and things are a little foggy

What your hearing is alternator whine and it's more than likely coming in through a bad ground but there are many other places it can enter. As you said it can come in from wires moving around this is more likely to happen with the low level lines feeding the amp(s) if they don't have good shielding.

Tell us a little more about your system like where things are grounded at, does your radio drive any of the speakers in the system, how many amps are you running, are they grounded to the battery or the car.

Do your amp(s) have a delayed turn off (stay on for a little after you turn the radio off then go thunk)

Later
Kelly

If you think you might have a problem within the car, try using a small AM radio tuned to random air waves(no station) and move it around the engine compartment and firewall. You should be able to hear it in the radio and track it down a little easier.

I agree with the failing alternator scenario, get that checked first

Aight, I will check into the Alternator for sure.

In the car, I have a Alpine head unit. Front components are run off a alpine amp in the trunk. Also in the trunk is a 12'' JBL sub, which has a alpine amp to itself as well. Both amps are grounded to metal-ry in the trunk, near the spare tire. I recently made a new floor board for my trunk, and very well may have ripped off the ground, I will be checking that momentarily. The only speakers running off the head unit are the back speakers, which I dont hear at all, and most of the time are faded off. Only time they are on is if someone is sitting in the back seat.

Thanks so far everyone!

-C

You know something else? I have been noticing that my car is taking more time to start. It takes more turns to actually turn over. I bet this is all connected. I will check my voltage on my battery when I get home from work. What should the battery show when the car is on, and battery is being 'charged'? 14.78 volts or something near that yes?

Thanks.,

Cameron

what type of car is this?

check your spark plug wires, what type are they?

Are they good type or cheapo's also your plugs. this happened to me a while back, got good insulated 8.5mm msd wires.

Are you uing stock ignition or aftermarket type?

Jim

Cameron,

Try this unplug the line level inputs on the amps or just turn them off if you can, fade to the rear speakers and see if you can hear the whine in them, if not then your problem is some where from the line out on your head unit to the amps or their ground. If your can hear the whine in the rear speakers then the problem is farther up front in the wiring.

Later
Kelly

I'd talk to an audio shop about it. I don't know a whole lot about car audio, but I've read up a little about it recently, and I believe there is something called an alternator tap, basically a filter that helps eliminate the noise you're describing.

I could be totally off base though, my advice is worth what you paid for it

Well, I assume your RCA's going to the amp are well away from your power wire, and any other large power wires in the car. And they are high quality sheiled type. Then it could be a bad alternator if it just came up without you doing anythign or anythign moving around. I've had alternators actually whine themselves when the bearings go south. It's quite loud and you can't "turn it off"

Charging a healthy alternator should do 13.8volts regulated. I had to replace mine (which was very healthy) because the stud that held the power wire on broke inside Now the replacement one charges the car at near over 17volts! (eek) and whenever there is a draw (turn signal) it drops WAY low (like 11volts.) I don't plan on this one living very long. Darn re-built alts. They are free (lifetime warrenty) but it's luck of draw when you end up with a good one. I wish I could of kept my other one. I did notice this one has a revised stud I guess they fixed that problem...

are the wires to the front speaker ran next to your amp power line? run power and remote down one side and speaker wires and rca jacks down the other...

also make sure everything has a good ground in one common point so you dont get a ground loop...

i used to be all into competitions.....

I have a powerfull multi amp stereo in my car

it whines when I fry diodes in my alternator.

my stereo can draw 1.3 kw from the car.

if you own an ociloscope it would be easy to see

1.3 KILOWATTS?!! Wow! Do the headlights dim when you turn it up?