Hey guys,
So i finished installing my system, everythings great but there's this whining, It's weird because the high pitched noise comes from BOTH front speakers/tweeters only when my car is turned on...it is also there when the stereo is OFF.
i have the bose sys and basically tapped the wires before the bose amp into my DLS amp, w/ up6's...have not yet finished installing the rear fills yet. i am using stock HU....

i've tried the following to get rid of it (via search function..)
1) check ground - noise sitll there
2) move rca's inputs away from the power wire - noise still there
3) turned amp gain all the way down - noise still there
4)unplugged LEFT channel of the RCA inputs on the amp - NOISE GONE
5)unpligged RIGHT channel of the RCA input on the amp
while the LEFT is back in - NOISE GONE
...so the noise only comes on when BOTH my RCA R and L channels are plugged in. Any suggestions? Did I just wire something wrong? errrr....
6) Xcrossovers mounted in doors - so shouldnt be a problem?

any suggestions would be great? was thinking about a ground loop isolator? not too sure if it fits this application...thanks

 

sounds like a ground loop prob to me...

 

I got noise when i swapped out my head unit and put a sub and amp in. I used a LOC (line output converter) to reduce the noise. its not 100% gone, but about 95% reduce. i don't even hear it anymore.

 

you can get an insulator that will eliminate the problem. any good stereo shop will be able to help you. i'm assuming the pitch increases with engine rev...a common problem.

 

nope not really...the engine rev doesnt really increase the noise..its like a constant very high pitched humming at a very very low volume. I can only hear it when the stereo is turned off because its at such a low volume...and only when BOTH my left and right RCA input plugs are plugged in. Very annoying. I thought it might be my crossovers in the doors but i used a test speaker and hked it up and it had the same hum...

 

Can anyone explain why there is that humming sound when only BOTH right and left channel RCA is plugged in? It's not there when i unplug either one of the RCA inputs...which leads me to believe it maaay not be a grounding thing. arrgh.

 

Are you using some time of LOC after you tap in before the Bose amp? I believe the DLS amp requires the use of an LOC to convert the balance differential signals into regular signals. That may be the problem

 

The DLS have been used without LOCs before with good results.

dukieman, do you have a "Y" adapter? I'd be interested in what happens if you run both channels off of one RCA.

 

At first i used some crappy RCA's, which didnt seem to work well.
Then i got that totally unworth it JL speaker to RCA adapter because i didnt want to wait.... I think that might be screwin me up right now because i connected that w/ some 16ga speaker wire and that to the input before the bose amp...very short run though, but still...I just ordered a pair of twisted RCA's which should be coming this wk...no LOC.

eldude, so maybe i can try hking the 2 incoming (+)'s onto one of the (+)'s and the 2 incoming (-)'s onto the 1(-) on the JL adapter? i'm assuming that's what you mean..

btw the very low level high pitched humming/buzzing sound is only there when my engine is on. weird. thought it could be charaterzied as engine noise but the RCA thing is tripping me out.

 

I kind of doubt that it's the wire thing.

Maybe this weekend we can troubleshoot it over the phone.

BTW, here are some ground loop isolators compared:

http://kward1.homestead.com/GLIcomp.html

 

I have the same issue. I'm running an Alpine Flex 2 channel amp for from MB Quarts fronts and a Hifonics Brutus 1000 mono for the sub. Removed the Blose sub and tapped into the speaker wires in the trunk. I've tried a number of different combos including the speaker wire to an AudioControlLc6 to rca's to the amps, speaker wire directly to the speaker wire inputs on the Alpine, soldered rca's to the speaker wire and ran them to the amps, speaker wire to a home made "balanced" connector (computer mouse cable cut and spliced to speaker wire, it fits the hifonics balanced input which is a mini 6 pin din, basically the same as an s video din, but the plastic piece in the plug is vertical plus 2 add'l pins) to the balanced input on the hifonics amp and rca out to the alpine amp. Turned the gains down, checked the ground etc. with no luck. I still have the noise, engine on stereo on or off. I was using an old school punch 150 and didn't have as much noise, but the Quartz' sound significantly better with the Alpine.

The weird thing is that I originally did a quick hookup with the Alpine amp to test it using the speaker wire connection and the power/ ground connections from the LC6 and didn't have the same level of noise, but I now can't seem to get it back down to the same level.

By the way, is anyone else having issues with the sound quality of their sirius sat radio? Mine sounds like sh**. FM radio sounds better. Any suggestions?
I'm also looking to sell/trade the LC6 and/or get a new sub enclosure (10inch). If anyone is interested let me know.

Thanks for any input.

 

Based on talking to this guy above yesterday on the phone, I'm not sure at all that you are having the same issue.

 

Any thoughts on correcting it while keeping the same components? From reviewing all of your posts, I know that your one of the most knowledgable dudes around on these issues.

Or, do think that the problem will not be eliminated until I add either an LOC or EQ with balanced diff. inputs or change my amps to JL's or some other make with BDI's? If so, do you have any suggestions trying to keep the $'s to a minimum, I'm kind of short on cash right now. Finally, do you still have a JL10w6 4sale?

Thanks for your input.

 

OK, I'm not totally sure here from your post, but you have the same noise with the stereo on or off?

Is the amp on with the stereo off? (Check the LED).

If it is, pull the amp fuse temporarily and check for noise. If you still have noise, the passive xovers are too close to a power wire emitting EMI.

If the noise goes away with the amp fuse pulled, then:

Does the noise vary with engine RPM?

Is it a whining or a constant hiss?

From your post, I can't tell if you've tried the OEM balanced outputs into the amps, but neither of those amps has a good reputation of liking balanced signal inputs.

I'd consider using a Soundgate LOCPREA or even a LOCB.2 on the HU preamp outputs instead of anything on the outputs of the amp. I am an Audio COntrol dealer but I wouldn't use one in that situation.