Whining Sound through Speakers when Engine Rev'd

[fbtrav3]

I recently replaced my bad Bose speakers with a set of aftermarket speakers and an amp. The salesperson at the well known shop had done multiple NSXs before without any problems in hooking the stock deck up to aftermarket equipment; they used something called a "hi-lo" converter in the process. I got the car back and the new setup sounds great, but when I rev the engine now, I pick up a whining sound through the speakers. It doesn't happen everytime and the volume seems to vary, but it is really annoying. I have taken it back to them several times so they can fix it but there has been no success thus far. The next thing they are going to try is replacing the amp and the converter. Multiple people have told me it is probably just the stock deck no working well with aftermarket equip, but I am hoping that is not the case.

Has anyone else experieced a similar problem to this and possibly know what may be causing it? Any info anyone has would be great, I could then pass it along to the shop to help them fix this thing once and for all.

Thanks!

[This message has been edited by fbtrav3 (edited 03 December 2002).]

 

[fangtl]

Alternator noise/whine. Most likely causes:

1) Too much gain
2) Power and RCAs are touching
3) Bad ground

 

[D'Ecosse]

I had identical symptoms! In my case I thought it interesting that I could turn volume to minimum & the whine would still be at same amplitude.
I did 3 things that helped as suggested above - I shortened the length of the ground wire to the minimum, kept the power cable away from the speaker wires (which were routed close together in my case) but I think where the big bang for the buck was in adjusting the crossover frequencies & gain on the amplifier.
The result is I not only got rid of the whine, but even more pleasing is that the mid-range is richer relative to the other frequencies - it was all bottom & top previously, overwhelming the mid-range.

[This message has been edited by D'Ecosse (edited 03 December 2002).]

 

[fbtrav3]

Thankyou both for the info. I passed it along to the installer...I guess we'll see if they are able to fix it.

 

[tewills]

Does this problem have anything to do with the ignition coil problems documented in the FAQ? Look it up. If I remember correctly, this is a well known problem, that if the installer had worked on a number of NSX's he would know. I think the recomended fix is replacement of the coils.

 

[fangtl]

If the car's in your possession right now, just go and try to turn down the gain with a flathead screwdriver. If this guy is really experienced I doubt he would've had the RCA and power run down the same side of the car, nor would he placed a bad ground. Try the gain first yourself, and if it still whines then ask your installer to look at it.

 

[D'Ecosse]

I agree with Fangtl - my other details were more "housekeeping" but primary cause was gain too high. Check the manual for details - if you don't have it you may be able to find it on-line from the amplifier manufacurer.

 

[NSX2NV]

If none of the above work you can get a groung loop isolator from any stereo shop. You attach your RCA's to one end and the other end to the amp. This should eliminate any whining noise. But try the above suggestions first and use this as a last resort.

 

[AKUDOU]

My 93 only does this when the A/C is on.