crazy idea

ilikesound

is it possible to get your music to come out of the horn when you hit it? cause horns are pretty loud.. lol. just wondering if anyone has actually done this, or if its even feasable..

ilikesound

on a more serious note...im getting bad whine from my system and nothing has seemed to help solve this issue. it used to come and go, and now its just there.
here's my system in a nutshell

alpine cda9857 HU
polk momo tweets and woofers in front being powered by c400.4
JL W3 powered by JL sub amp.
ipod integration

so there you have it. ive re-ran ALL wires and checked grounding points and everything, and still have the noise. i KNOW its alternator whine, it sounds more intense as i rev or speed up the car in motion. it only comes on when the ACC is on, or the car is on, never when just the elec is on. so im officially stumped. ive even added RF stoppers near the amps just in case. please are there any "un-conventional" ways to fix this problem? im short on cash atm...
thanks

Greg Peters

Without knowing whether noise is present through all speaker channels, or just a select one, try an experiment (to see if noise might be entering via the HU power/ground leads)...

Run a new and possibly larger constant power wire from battery (or at least from the fuse panel) to the head unit, bypassing the one in the factory radio wire harness behind the dash. Run a similar gauge new ground wire to a known good ground as well. These don't have to be pretty or even permanent- they are just to help you isolate the source of the noise.

Sometimes noise is radiated through the factory wire harness, because it passes too close to a noise-inducing accessory along the way (heater blower, wiper motor, etc.). Noise from this source may not have been audible in the factory radio, but the amplified signal of the aftermarket head unit may pick it up.

Induced noise like this is most common when using an electrical adaptor to interface your head unit with all the wires present in the factory harness.

ilikesound

if the wire harness is the issue, how would i go about fixing it? doesn't the h/u need one to operate with the system? or does it just need a ground and power wire, since everything is running off RCA's to the amps? could i theoretically just put a power wire from the battery to the head end, and a ground to the chassis, directly into the wire harness for the unit itself, bypassing everything else along the way? would that work?

Greg Peters

If the wire harness is the issue (and you aren't using the HU's built-in amp to power speakers) but have all signal routed through RCAs to amp to speakers, you don't need anything other than the power/ground, an unswitched 12V source for presets/clock, a remote turn-on lead, and possibly the dimmer or power antenna lead connected.

Tie up all the other leads from the back of the HU and wrap any bare ends with tape- I suggest this because if you're only using external amplification and haven't disconnected the HU's internal amplifier with a Power IC on/off setting, you could try the "off" mode and bypass the internal power and see if that changes the noise situation.

It's OK to retain the unswitched 12V power lead (for presets/clock) from the factory wire harness, as its unlikely to be a noise source and draws minimal current.

The reason I suggested running new power and ground to the HU is that I've encountered noise on some cars with some equipment in the past that picked up the noise from improperly shielded accessories the factory harness ran in proximity to. Bypassing the power and grounds from the factory harness and running your own (away from under-dash accessories) can help troubleshoot the noise source. If doing so makes no difference, you'll have to look elsewhere. It seems from your earlier post that you've already troubleshooted the power/RCAs/connections from your amps.

I know some Pioneer HUs have some noise issues originating from the RCA inputs that require a portion of the RCAs to be grounded at back of HU for a fix, but I don't recall hearing of any Alpines with that problem.

System noise can be as simple as a bad ground or a power wire picking up induced noise, or as complex as a tinsel lead on the back of a single speaker contacting a metal portion of the car body. Never use a chassis ground that's mounted near an electrical accessory. In stubborn noise cases, you could even try common ground points for all audio system components (think ground distribution block) to eliminate a ground loop. You could also troubleshoot the antenna connection by disconnecting it and playing a CD while checking for noise.

exalted512

agreed, re-grounding the head unit usually helps
-Cody

ilikesound

there is a ground lead on the HU itself, which i put close to the head end itself..i don't know where else to put it, the honda accord has plenty of room behind the dash portion, just where to put the ground that will actually GROUND that's probably my biggest question right now. and also, if i ground the amps in the trunk under the floorboard where the spare tire is, how would i actually go about doing that? thanks much

Greg Peters

ilikesound wrote:

there is a ground lead on the HU itself, which i put close to the head end itself..i don't know where else to put it, the honda accord has plenty of room behind the dash portion, just where to put the ground that will actually GROUND that's probably my biggest question right now.

For a ground up front, you could find something structural and put it under an existing bolt (away from any electrical accessories) using a ring terminal with a star washer. Use emery cloth or a wire brush in a drill to take the surrounding area down to clean bare metal, then trap the terminal under an existing bolt.

ilikesound wrote:

and also, if i ground the amps in the trunk under the floorboard where the spare tire is, how would i actually go about doing that? thanks much

Have a really good look under your proposed grounding point to make sure drilling a hole won't puncture anything like brake lines/fuel lines/gas tank etc. and drill a hole big enough for a bolt. Use a ring terminal, and clean the surrounding area down to bare metal (as above). Streetwires makes some nice ground blocks that bolt to a chassis ground and take large gauge wire as well.

If you really want to be particular about things, ground all stereo components to a common ground point in the car- that will minimize any chance for a ground loop to cause system noise.

I forgot to mention- sometimes noise creeps in through amplifiers when you use large gauge power wire but smaller gauge ground wire. Ideally, use the same gauge wire for power and ground.

ilikesound

ok here's an update. i went through absolutely ALL these suggestions, only to come to the realization that its an issue with my polk amp. what...the ****. so its gonna be a chore getting the new amp, since i recieved it thru employee accomadation because i work for a store that carries them. man...who would have thought that a moderately high quality amp was to blame?

1996blackmax

It happens.....