hey guys today i decided to rewire my system, i removed the outboard crossover and decided to use the one in my deck i have a pioneer 7600mp, before i had the rear output from the deck going to the crossover and the high out from the crossover going to my 4ch sony xplod and the low output from the xover going to my alpine M350 mono amp powering my 10inch alpine typr R..... so now i decided to take out the xover, so i have the rear out from the deck going to the rear input in the sony and front output on the deck going to the front input on the sony, and SW out on the deck going to the alpine...... i'm hearing that whining noise that increases when i press the gas, as soon as i unhook the front RCa cables the noise goes away.... now i think my ground is ok, it was ok all along why now would it be that... and i have my rca cables running on one side of the car and power on the other... and other ideas on what can cause this???
Ryan, you have a ground loop. If you have multiple ground wires, you will get noise. Also, if you have multi preouts on the HU, it can also cause ground loop. Some units function fine as long as you separate the fronts and rears using 2 amps. You might also want to check the ground on the HU.
nick_sq
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i have the exact same problem. I have 2 amps, one for subs and one for mods/highs. If i only run a single set of RCA'a off the rear output of the deck for both amps i am fine. But if i try to run another set of RCA's off the front outputs of the deck i get noise. It is not altenator noise, it is actually the noise of the cd spinning/reading (kindof a squirrly noise) It is not localized to and 1 output (front or rear) but it only makes noise if both sets are hooked up. If you fix your problem, i would be glad to hear about it.
thanks for the advice, well what is the remedy for a ground loop, i do have both my amps grounded to to separate seat belt bolts under the rear seat, should i try different ground locations? is there something i can buy? this is killing me, i know you car audiophiles can relate, the little problems are the worst!!!!!!
Before you buy anything else, try finding a good ground. Who installed the ground in you car? You really have to drill a hole in the chassis and sand off some paint. Then install 4gauge or lower onto it. Do you have power distribution block? You need one for pos and ground. I share one ground wire for multi amps in my car. After you get a solid ground and distrib block, test the amps by hooking up a walkman or portable cd player. Get couple of rca splitter and connect both amps to it. Then feed the signal from the portable and see if you hear any ground loop. If you don't then the amps are fine. You then test the HU. Test each amp separately, then hook both to the HU. If the noise comes back, then you have a ground problem between HU and the amps. You probably then have to find a better ground for the HU. If you do search on ground loop, you might find a device for getting rid of them. The only problem is, it also has some effect on sound output from HU as well. I'd do that as a last resort.
well heres my update, i tried different rca wire and the same noise ocurred, i have three pre outs on the back of my HU, rear, Front, and sw, no noise comes from the rear output, but front and sw preouts make the noise when connected, i even unpluged my anttena and still no change, so i'm thinking it can't be the ground, cause how can one preout work and the other two has noise? and it can't be the rca wire and cause i tried different ones and they all make the noise.... could it be the HU????? i just bought it brand new last year!!!
sorry i isaac, i never saw your post, i installed my own ground, i have a 98 sunfire, i installed the ground under the rear seat to a seatbelt bolt, i sanded it down to bare metal, and i tried both seatbelt bolts, no change, i have both amps (hi/sub) grounded at the same spot, i bought a noise cancelation device hooked up to the front inputs, the noise went away but the music now has a reverb, concert like effect out the front speaker.......