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Discussion Starter #1
Hi, I drive an 09 g8gt and started a build thread here and am all but complete except for gremliest alternator whine I've ever come across.

Build:
Factory HU to RE-Q5 processor/loc
Stinger pro 4 channel rca's to kenwood x4r to ID oem's in doors and atomic 1.2" tweets in dash.


I've taken it to a shop or two but am pretty much out of ideas. I even called the re-q company and was told it didn't have the best filter out there by one of its representatives.

My last resort scenario is now to relocate the re-q from the hu to my trunk with the rest of my equipment (battery is located in trunk as well) but that would mean taking my car apart again as well as losing fader etc. controls at the hu which I would like to keep.

I'm now wondering if switching to something like the 360.1 or .2 would filter out the noise from the factory hu and wiring better than this thing did(while also possibly relocating to the trunk).
 

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Are the fronts active or passive xovers?

Does you car have an OEM amp? If so, are you connected before or after the amp?

There is no way to "filter" ground loop noise, which is probably what you have. If the noise was actually in the signal out of the HU, you would be screwed. Ground loop noise is not part of the signal from the HU, but is an artifact of the signal connection.

Unplug the RCAs at the amp. Do you still have the noise?

If so, and the fronts are passive, disconnect the speakers at the amp. If you still have noise it's the passive xovers picking up the noise in the inductor coils.

If disconnecting the RCAs kills the noise, try a ground loop isolator between the ReQ and the amp.
 

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Are the fronts active or passive xovers?

Does you car have an OEM amp? If so, are you connected before or after the amp?

There is no way to "filter" ground loop noise, which is probably what you have. If the noise was actually in the signal out of the HU, you would be screwed. Ground loop noise is not part of the signal from the HU, but is an artifact of the signal connection.

Unplug the RCAs at the amp. Do you still have the noise?

If so, and the fronts are passive, disconnect the speakers at the amp. If you still have noise it's the passive xovers picking up the noise in the inductor coils.

If disconnecting the RCAs kills the noise, try a ground loop isolator between the ReQ and the amp.
 

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Discussion Starter #4
I'm running a 2 way active front, so no crossovers but in this car they have to be mounted in the rear I think to avoid noise.

Disconnecting the rca's at the re-q5 stops the noise.

The only ground loop I might possibly have I thought was having weak factory grounds for the hu, added a couple 16 or 18 guage wires by tapping into factory grounds on the harness and touched the end of those wires to a chassy ground and nothing changed.

But if it was the re-w specifically, I decided to wrap wire around it and touch the wires against the same chassy ground and nothing(going off of what some pioneer users had to do with their rca outs on their hu's)
 

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Stay away from the 360.1/.2 Flo! Those things are notorious for failing in the Bluetooth section which leaves it worthless. Get with Paul though as I think he still has a JL Cleansweep for sale. If not, then see if you can't score a used DSP unit off of here (Zap DSP6 would be my #1 choice since you are only run a 2 way front.) If you need anything, shoot me a text or call.

Zach
 

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Disconnecting the rca's at the re-q5 stops the noise.
Classic ground loop indication too.

The only ground loop I might possibly have I thought was having weak factory grounds for the hu, added a couple 16 or 18 guage wires by tapping into factory grounds on the harness and touched the end of those wires to a chassy ground and nothing changed.
Test with a ground wire running to the HU from the ReQ.

h
But if it was the re-w specifically, I decided to wrap wire around it and touch the wires against the same chassy ground and nothing(going off of what some pioneer users had to do with their rca outs on their hu's)
Which really doesn't tell us much, sorry. Worthy experiment because it's easy, but it not working doesn't yield many clues.

Does your HU have speaker out or preamp out to an OEM amp? What voltage is the output? Where are the ReQ input gains? The amp input gains?
 

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im sure im going to have this problem since i have the same car. but i am using zapco dc amps...so hopefully the balanced inputs do their job and reduce the noise....if not i will be one frustrated mofo
 

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im sure im going to have this problem since i have the same car. but i am using zapco dc amps...so hopefully the balanced inputs do their job and reduce the noise....if not i will be one frustrated mofo
This board has a lot of people who seem to know sound, but few who seem to understand noise.

Balanced signals reject INDUCTED noise - noise picked up on the wires carrying the signal to the amp. Does nothing for ground loop noise in and of itself.

While Zapco balanced transmitters and BTL LOCs do a pretty good jobof preventing ground loops, you can still get ground loops if things aren't wired correctly, and some tesing (and provision for testing) is always called for.

The industry stayed away from OE integration due to noise fears for 20 years. Now you guys all expect OE integration to be cut and dried and automatic and stuff? There is usually testing and trial-and-error involved.

But one way to make your OE integration go better is to do the amp first, on OE speakers. Use them to get the noise out. Then by the time you do your speaks you know it should sound great (or any noise is due to your passives...: )
 

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Discussion Starter #9
Thanks for the help VP I was up all night reading about the bitone which will be my next processor...

I know the rca grounding trick was just that, I was running out of ideas.

I actually also did try running a ground from the hu to the re-q and running two grounds from the hu and e-q to common ground...basically just trying different points and things which might actually create a ground loop just to see if things would change at all.

I'm going to try just a basic loc today to see if its mainly my re-q5 and will also try regrounding my factory hu and re-q5 in the same spot in the trunk by the amps, as well as grounding my factory hu there and moving my re=q5 to the trunk last.

I also have a couple more things I want to retry.

And ya Zach probably wont go with a 360, I'm looking to get a bitone from a local shop, going to try and solve my noise issue with me for free I hope if I order that thing today.

Edit:
Need to rmember a couple more things I tried like ground loop isolator etc.
 

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Discussion Starter #10
Ran wires from hu to trunk to a 20 dollar loc then to amp and now more noise!

Going to try it with the re-q5 next and then will plan out my system for a possible bitone and vmod add-on.

I have a build thread here I can finally update and finish.
 

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Discussion Starter #11
Moving the re-q5 to the trunk didn't help lol.



Got no alterntor whine as far as I knew today using a cheap loc, but am still having trouble with the re-q5 but we'll see I guess.
 

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Discussion Starter #14 (Edited)
Worth a try I'm going back to the shop to try it out, then if that doesn't work I'm going to try the loc, thelocs voltage might have just been lower than the re-q5's and so I didn't hear the whine.

Edit:

I got fed up with the re-q5 and didnt even try another filter again, just ripped that piece of junk out and out in a cheap loc and some shorty rca's and no more alternator whine...
 

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hey did you ever figure this out or did you really just rip it out? lol

i just got my req5 about a week ago and im having engine whine also.

rcas are no where near any power cables (tried running them outside the car) have regrounded and done quite a few things, tried everything manufaturer has told me and nothing yet.

help me out if you can, please. this stupid whine really is annoying.
 

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I had the same problem with a reQ-5. A noise filter on the PWR input to the reQ-5 solved the problem. I recently replaced it with a AudioControl LC6i which has much better sound qualities (detail, separation... etc). I did not remove the noise filter, therefore I'm not sure if the LC6i suffers from the same problem.
 

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thanks for the tip.
do you have any link or name/model of the specific one you used?
ive tried a couple of ground loop isolators and nothing. so i want something that work
 

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thanks for the tip.
do you have any link or name/model of the specific one you used?
ive tried a couple of ground loop isolators and nothing. so i want something that work
I used one that I had purchased at RadioShack back in the early 90's. When I encountered this problem last year, I was having a difficult time location one at any of the local car audio shops or electronic stores. Luckily I remembered seeing the filter on a piece of old car audio equipment (AltecLansing ALC 10) in my basement which finally ended my search for one. This link shows some similar units PAC CSS-5 (css5) Noise Filters Car Amplifier Installation & Accessories Car Audio/Video Installation & Accessories Car Audio, Video, & GPS Navigation - Sonic Electronix
 

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I had the same problem... we tried everything to finally find out there was static in the connector...:( We tried soldering the connectors to solve the problem but it didn't work... I'm seriously thinking about buying a new head unit...
 

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I had the same problem... we tried everything to finally find out there was static in the connector...:( We tried soldering the connectors to solve the problem but it didn't work... I'm seriously thinking about buying a new head unit...
honestly, the req5 is a pretty decent piece of equipment. it has a lot of good features for a solid price that pretty much cant be beat.

BUT:
it can defintely be a ***** to work with. ive had so many damn problems with it, it sucks. once i got it to work, it ran smooth for quite a while, then it messed up on me and now im back to hassles on it. ive tried replacing it, but nothing has the same features that this one does. or at least for me this unit has everything i need at a great price.

as for your alternator noise. do the following to reduce noise substantially:

-ground it directly to your amps.
-power it directly off your amps.
-add a power filter (as mentioned above) tot he power wire on the req5.

i didnt add the filter but just by grounding and getting power from the amp that im sending singal to, it reduced my noise dramatically. so definitely try that. also try sodering your connections. i originally had used t taps to tap into factory wiring and once i sodered everything and got power/ground from amps, noise reduced quite a bit, to where i have to try to hear it in order to know its there. still sucks but at least passengers dont know its there.

lmk how it goes. good luck. or let me know if you will use another oem processing unit to replace it.
 
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