builderman918 Posted April 20, 2012 Report Share Posted April 20, 2012 Just finished installing a 4 channel amp (already had a sub installed via RCA's) and there is no whine noise when the key is in accessory but when you put it in the "pre start" / when the car is running there is a whine through all the speakers and sub. I don't believe it's alternator whine since it happens when the engine isn't running and it doesn't go up and down in pitch when accelerating/decelerating. What would cause it to start whining when in the key is in the pre start position. To give an idea of noise level if the unit is above level 8-10 then you really can't hear it. Quote Link to post Share on other sites
builderman918 Posted April 20, 2012 Author Report Share Posted April 20, 2012 I've read about the pico fuse blowing but it seems that the noise from that is extremely loud, such as having the unit up to volume 25 to drown it out. Does anyone know if you can have this quiet of a whine like i have from a pico fuse blowing? Quote Link to post Share on other sites
1loudls Posted April 21, 2012 Report Share Posted April 21, 2012 this does sound a lot like it could be the pico fuses, one other thing that i have seen is the signal ground go bad with some pioneers. this is actually very easy to test, take a small piece of wire, and stick it kinda into the RCA as you are plugging it in (sorry kinda hard to describe) so that it is only touching the outer part of the RCA connector. and then ground the other end (you will need to do this for each RCA) however, i do think that it is kinda weird that it doesnt happen when the radio is in ACC, you may have something in the cars ignition system that is emmiting interference, and the radio or the RCA cables is picking this up. kinda like this http://www.youtube.com/watch?v=dje-CG4UGQ0 sorry this is not the best video, but its the first one i found that covered the problem i was talking about. he calls it a "static noise" but its more of a whine that ive heard. and instead of wrapping a small piece of wire around the RCA's, i just insert a little bit of the wire in the outer ring of the plug as i am plugging it back in. Quote Link to post Share on other sites
builderman918 Posted April 21, 2012 Author Report Share Posted April 21, 2012 I grounded each rca to the avic and the sound is still being made...another thing is when putting the car in pre start all the amps turned on, no sound, pioneer unit says starting up and right before the music plays the sound starts to happen...any advice where to go from here? I wouldnt think a new ground is needed for the avic since i didn't have any noise when the speakers were powered just by the avic. Does it lead to being some sort of Interference in prestart when the signal goes through the rca's since there is no whine when in acc (so that means the pico fuse should be intact correct?) Quote Link to post Share on other sites
1loudls Posted April 21, 2012 Report Share Posted April 21, 2012 not 100% sure on that, ive never had to do the repair, but i have seen it a couple times. Quote Link to post Share on other sites
builderman918 Posted April 21, 2012 Author Report Share Posted April 21, 2012 I took the unit apart and tested for continuity across the pico fuses and all are fine, non blown Quote Link to post Share on other sites
builderman918 Posted April 21, 2012 Author Report Share Posted April 21, 2012 I get noise in the sub from the cd player reading the nav disc so it just must be the way it is Quote Link to post Share on other sites
1loudls Posted April 21, 2012 Report Share Posted April 21, 2012 well it might be a problem with the sound board in the actual unit itself, when no music is playing there should definitely not be any noises coming out of any of the speakers. it never did this before adding the 4ch amp right? Quote Link to post Share on other sites
builderman918 Posted April 21, 2012 Author Report Share Posted April 21, 2012 Actually i think the sub always make the thumping sound with the radio but just thought it was the fuel pump and other thngs starting up since it isnt that loud and its in the trunk back when i didnt have the 4 channel...i just added another geound to the radio and im pretty sure the thumping is gone but the whine still remains Quote Link to post Share on other sites
builderman918 Posted April 22, 2012 Author Report Share Posted April 22, 2012 The Noise gets louder and softer when turning the gain on the amp up and down. With the gain all the way down its barely there. Could it be the amp creating the noise? It's an MB Quart ONX4.60 Quote Link to post Share on other sites
builderman918 Posted April 22, 2012 Author Report Share Posted April 22, 2012 Also could the ground be picking up the noise Quote Link to post Share on other sites
1loudls Posted April 23, 2012 Report Share Posted April 23, 2012 well i doubt that it is the amp that is creating the noise, usually if there is an internal problem with an amp that causes it to make a noise, the gain wont effect it (not always but usually) however if the noise is getting picked emitted from somewhere in the car (again, most likely something in the ignition system, since it doesn't happen when the key is in acc, and it can happen when the motor is not running (definitely not the alternator)) the RCA's could be like an antenna for this and picking up the noise and then the amplifier is boosting up the level (which is why the gain will effect it) if the amp was creating the noise, it should happen any time it is on, even in just ACC. Quote Link to post Share on other sites
1loudls Posted April 23, 2012 Report Share Posted April 23, 2012 more things to test. does the amp make the same noise if the RCA's are unplugged? if so, i would try for a better ground, or test with a different amp if no. does it make the sound with the rca's plugged into the amp, but not the radio? (if no on the first but yes on the second, you need to reroute your RCA's or you have a bad RCA and need to replace them) if no again, im back to suspecting the radio, you could try to unground the radio from where it is, and run a temporary ground from the radio back to where the amp is grounded, if this doesn't help i would test with a different radio if possible. also if it hasn't been done yet, the power system for the amp needs to be tested for voltage drops, and the factory power wires need to be looked at. Quote Link to post Share on other sites
builderman918 Posted April 23, 2012 Author Report Share Posted April 23, 2012 New grounds to the radio did nothing, when i unplug the rcas there is a tiny amount of noise (probably inaudible if sitting in the seat), when i plug in the rcas im using without them being plugged into the headunit i get really bad static/interference/buzzing and when i plug in some rca cables i got from the house there is silence....so is it those kicker rca's? Quote Link to post Share on other sites
1loudls Posted April 24, 2012 Report Share Posted April 24, 2012 sounds like it, but it may or not be a defective cable, it also could be some factory wires or modules that the cables are routed near that is emitting the interference and the RCA's are just picking it up. Quote Link to post Share on other sites
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