Randomly today I started hearing alternator whine. I have a audiobahn a8000t powering a memphis 12" power reference sub. I unhooked the rca cables from the amp and tried different ones, to no avail. I also tried new speaker wires and no avail. Tried a few different places for the amp groun, no avail. None of the wires have any cuts or are being smashed by anything. RCA wires are routed from the passenger seat where my amp is located to the driver side and to the headunit. All power wires are routed on the far passenger side of the car from the firewall to the amp and then the speaker wires go from the amp to the back of the car on the same side. The whine volume gets very low, almost not noticeable if i turn the gain on the amp to 0, but then whats the point of the amp. Does anyone have any idea what could possibly be causing the noise?
Thanks and I hope this is the right forum category.
alternator whine is almost always a grounding issue. sometimes RCA's are crap, but you said you alredy tried that.
have you tried to relocate the HU's gound?? are the ground points you are trying for the amp clean and as short as possible?? (no paint, rust...ect...bare metal)
grounding and sometimes location of the RCAs. I had an issue when my RCAs ran along the edge of the car due to electrical wires running along with it. I then moved mine to the center of the passenger side of the floor and had no problems.
like i said, i even tried different rca wires, which really shouldnt be a problem since i am using new JL audio premium interconnects. Today I tried using one of my other amps and I still had whine so im thinking that its a filter on the alternator or something. All the ground points I used are bare metal, clean and not more than 10" away from the amp.
did you know if the RCAs run over or along side a bunch of factory wires or onboard PC? in imports there tends to be a on board PC unit that gives off alot of interference around the passenger footwell and directly behind the center of the dash. Also there is usually a big glob of electrical wires in the passenger side right where the door hinge is. Also your ground spot still could be the problem if the spot is not either part of the frame or directly connected to the frame. I typically find where the factory grounding spots are and then make my spots next to it.
i think im going to try the ground loop isolator. Only the power wires are near that big pc unit so i dont think thats the problem and the rcas are crossing where there are no electronics near the shifter then going to the back of the headunit. Any other suggestions? Thanks.
got a ground loop isolator from radio shack but it wasnt what i wanted so i returned it. I drove home with the whine and then it just stopped and it seems to be gone now. wow, any ideas of what it could have been?
if it went away all of a sudden there's a good chance it will return all of a sudden. Try grounding all your audio equipment to the same point on the frame. Barring that, there are some cars that just have more inherant whine than others... I had a 97 BMW M3 and there's so much electrical in that car that whine was very difficult to get rid of. Head unit may be a problem also. I used to have a crappy Blaupunkt in that same car and had alternator whine; I upgraded to a $600 Clarion Pro Audio with no internal amp and 4v preouts and the whine mostly went away. You may also try inline filters on your rca cables.