AcuraX2

Need some help badly. I just hooked up my JL 500/1 and my IDMAX (which is awesome btw). Some of you may remember, I had a noise problem with just the 300/4 hooked up but, I turned down the gains and could live with it. When I fired the 500/1 back up, the noise went crazy. All this with the engine off mind you. The noise sounds like listening to an AM station and the whine changes pitch up and down. It is pretty darn loud. I tried all of this but, nothing helped:

Unplugged RCA's to amps, noise gone
Used a muted cable, noise gone
Tried new ground point for amps, noise still there
Ran new remote wire outside of car, noise still there
Ran RCA's outside of car, noise still there.
Tried new ground for head unit, noise still there
unplugged antennae at brain and head unit, noise still there.

I am out of ideas. This is not a noise that can be lived with. Anyone who has a suggestion, please speak up. If I can not get something done, I will have to take it to my local installer and see if he can track it down. Which will probably cost a fortune. This noise has not always been a problem. When I had my Image Chameleons and a pair of ID12's, there was no noise like this. I switched to the Diamond M661 and took the ID's out and the small noise started with the 300/4. Then, added the IDMAX and hooked the 500/1 back up and noise started. Thanks.

dnd2984

iTrader: (6)

What kind of RCA are u using. Thats the only thing I can think of unless the RCA preouts went bad on the headunit.

ash3ktl

I had the same problem except the noise wasn't as loud as you say. But I could still hear it. This is what I did.

1. Get the twisted pair shielded RCA cable and ground the shield.
I bought it from knukonceptz. It did reduce the noise a lot.
2. Ground your HU and all the amps at the same point.
I still had some noise even with the twsted pair rca cable. But last night I grounded the HU to the point where all the amps are and the noise was all gone. Just make sure that you have a good ground point.
3. Ground Loop Isolator.
4. You can also test your amps by connecting the outputs of a portable cd player and see if the noise is still there.

These links might be helpful. Good luck.

http://www.acura-tl.com/forum/showth...threadid=56180
http://www.acura-tl.com/forum/showth...threadid=56730
http://www.epanorama.net/documents/g...oop/index.html

AcuraX2

Here is my update on what I have tried. These are in addition to the ones posted above. The thing that concerns me is that all this is with the engine off.

I ran a set of rca cables from my Alpine IVA-C800, that is in my MDX, to the 300/4 and 500/1 amps in the trunk of my TL. The noise was still there however, the cables are very cheap and I think that could be the problem with this test.

This morning, I hooked up a portable radio to the 300/4 and heard only slight hiss, acceptable hiss. I then hooked the portable to the 500/1 and ran some high quality Stingers from the 500/1 to the 300/4 using the pass thru of the 500/1. Still just slight hiss. I then hooked the rca from my Eclipse brain back into the 500/1 and left the Stinger hooked between the 500/1 and 300/4. Noise came back although not quite as loud but, still not acceptable.

I am going to go buy some really good long cables to be able to run then outside the vehicle and also try from vehicle to vehicle. I am almost positive it is not the amps and that it is further up the chain.

BTW...The cables in my TL are Rockford Twisted but, they are pretty old and maybe something happened to them.

Scott P

I am assuming you are talking about a high pitched whine that is somewhat constant, and even louder at times when the engine is running. If that is the case is sounds like a grounding problem. I would have to see where you have things mounted and where you are running your wires (incuding your power wire) but i bet the problem is simply location

AcuraX2

ScottP...No, it is not when the engine is running. It is there with the engine off or running and it does not change volume with the rpm or anything like that. I sounds like an AM station that is weak. The pitch will go up and down and then start over but all this with the engine off.

I stopped by my local installers and had him listen. I do all my own install but, he built me a great custom enclosure for my MDX and I hook him up with material from time to time from my machine shop. He said it does not sound like induced noise at all. He thought was that is was not in the RCA's but maybe either a problem with the Eclipse or maybe a bad power wire coming out of the Eclipse. I might try running power directly from the battery into the Eclipse. I think running rca's from the Eclipse brain into amps in the MDX might tell me alot.

Brewboy

I'll take a stab. I bet it's a ground loop within your RCA's between the HU and amps. Meaning, the RCA's are grounded at both ends creating a loop. You probably have continuity between your amp's RCA gnds and the amp ground. If so, you need to isolate your RCA's grounds with an isolation xfmr like a PAC OEM2 between the HU and your amps. Or maybe your HU has a jumper so your output RCA's grounds can float and be grounded only at the amp(s). I went thru this same thing awhile back and ended up using the OEM2 but I'm probably going to go with an AD product of some sort later on. Good luck.

AcuraX2

Brewboy...Thanks for the reply. Let me tell you what I tried today and you can tell me if you think it is ground loop. I am just out of ideas.

I tried all kinds of cable combinations and nothing changed. I developed another problem. My speakers will shut off at about 3/4 volume or just below. They will shut off and come back on and play for a few seconds and repeat this. The gains on my amp are all the way down to quite the noise as much as possible. I unhooked both speakers and used a test speaker straight from the amp and I still had the same noise. I hooked my Eclipse brain up the amps in my MDX and I could not hear the noise. I had hiss but, no pitch changing hum. I then hooked rca's from the Alpine in my other vehicle to the amps in my TL and the noise was still there.

I think that is everything. It seems nothing that I try has any effect on the sound, other than hooking up a portable radio to my 500/1 and then using the pass thru on it into my 300/4. Doing this there was no noise.

Let me know what you think.

dnd2984

iTrader: (6)

AcuraX2 you really really must be frustrated. At times like that I would just rip apart the whole system and reinstall it with all new wires. You didnt get your amps through a authorized dealer either so they wont be any help either. Call up JL tech support and see what they say.

AcuraX2

You have no idea. I finally get all the equipment that I really want and to have this happen. I have dealt with noise lots of times but, nothing like this. The really bad part is, it could still be about anything. Your idea of ripping everything out and starting over is not that far fetched. It is just a scary thought but, I may have no choice.

dnd2984

iTrader: (6)

I had to rip everything apart in my rsx. The problem was the front driver-side speaker was being grouned on the door. I mean little thing can mess you up big. again goodluck. I am assuming it will take u a good 3 hours to take it out and reinstall.

unlemming

It may seem obvious but it hasn't been said, did you try replacing the interconnects with twisted noise reducing cables? I had some cheaper monster cables in my car and then I replaced it with high quality stuff..sounds great now

Scott P

My post didn't quite say what I meant, now that I re-read it. It does sound like a ground loop problem though.

AcuraX2

dnd....not quite at the rip it apart stage but, getting closer

unlemming...i have tried everything from top quality to cheap and it makes no difference

Scott P....you may be right on that.


At the suggestion of someone on rec.audio.car, I am going to pull the 300/4 out of my MDX and swap it with the one in the TL. That would eliminate or guiltify, is that a word, the amp. The person that is helping me and is a long time installer. He said that with all that I have tried, the Eclipse and the Diamonds should be ok. I will say this, if it happens to be the JL amp, I am going to have to think hard about switching amps. That would be both my 300/4 going bad. It is kinda double edged, I hope the amp is not bad but, if it is, at least I know the problem.

AcuraX2

Well, that did not help either. Same hum and speakers still shut off. If I am correct, I have eliminated the 300/4, my Eclipse head unit, and the Diamonds, from being a problem. If this is a ground loop issue, would that be shutting off the speakers too?

dnd2984

iTrader: (6)

THere has to be a short in one of the wires somewhere. Take the door panel apart and check the speaker, but then the noise in the 500/1 still exisist. If u buy me a plane ticket and a IVA d-900 Ill rip it all out for you

AcuraX2

hehe, if I had that money to spend, I would trash it all and start over. For the cost of the IVA-D900 alone, I could buy all new amps.



I think just to satisfy myself, tonight I will take the 500/1 out and put my 250/1 in and see what it does. I know that does not really explain the speakers shutting off but, maybe it is all related. If it is not the 500/1 then, I may be out of ideas. I would have thought maybe the Diamonds were bad until I unhooked them and tried my Chameleon. I probably need to hook up a Chameleon and see if it will shut off. Could be two seperate problems. Diamonds may have a bad wire and something else is causing the hum.

Boy is this fun!!

dnd2984

iTrader: (6)

arent u happy now that you dont have kids yet. Ok u traded the 300/4 from the MDX in the TL and it was still doing the same thing correct. How do both amps function in the MDX.

Scott P

out of curiousity, where are you running your power wire from the battery through? did you use a pre-existing hole in the firewall, or did you drill your own? moreover did you use a grommet and properly shield the wire?

I doubt it that the problem causing the distortion is the same problem causing the speaker shutdown.

Out of curiosity what amp are you using when the speakers are shutting down? b/c that sounds notoriously like a protection circuit in the amp that would shut it down for a moment or so and then comeback on and start the process over.

AcuraX2

dnd...Both 300/4 amps work fine in the MDX. No hum at all. BTW...found out 2 weeks ago, we are expecting our first child April 30th.


scott....ran thru the large rubber grommet that is already there for the power wire. I have tried 2 different JL 300/4 amps and they both shut down. I am leaning more toward two seperate problems myself. While at work, I unplugged the RCA's from my 500/1 and ran 2 sets of RCA's into the 300/4. Had to rewire the speakers to just the front channels but, all 4 channels of RCA's are hooked up to the 300/4 and the 500/1 has no RCA's hooked up. The humming noise is gone. Still a slight hiss but, no hum. This might mean something or nothing. Once the wife gets home tonight, I am going to swap out the 500/1 for my 250/1. I am hoping I found the humming culprit. I am also going to do some more testing on the speakers to see if one at a time will shut off. Maybe it is just one making both shut off.

AcuraX2

Update....

I finally found the humming problem. My 500/1 has a problem. I swapped it out with my 250/1 and there was no hum at all. Great, I have 4 JL amps and 2 have had problems. Not good in my opinion.


I still have the speaker problem. I tried unhooking one speaker at a time and the other would not shut off. Only when they play together. And it is in fact the 300/4 that is shutting off. I had a speaker hooked up to the rear channel in the trunk and even it shut off. So, the entire amp is cycling on and off. The thermal light and ohms are not lighting up. Any more ideas on this one?

dnd2984

iTrader: (6)

congrats on the kid x2, he will have one pimpazz system when he turns 16.

Didnt you wire your 300/4 bridged? I was told by the audio shop never bridged your highs. I am thinking the crossover might be turining the speakers off. Did you call JL tech?

AcuraX2

That may go along with what I tried. I have a CD that has a killer bass hit in it. When I bridge the amp, the amp shuts off at that point. When it was not bridged, it did not. Sounds a little off to me though. I have not talked to JL. I have been emailing with someone from Diamond but, nothing has worked yet. I have never had a problem with an amp shutting off speakers so, I am new to this one.

Scott P

Good job on finding the feedback problem. As far as the shutdown problem, the first thought would be power overload, although I somehow doubt that would actually be it. It could simply be a faulty circuit though