T
Turbo Dog
Guest
What's the best way to eliminate it? Thanks!
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T
Turbo Dog
Guest
The stock radio did not whine. I replaced it with a Jenson and tracked all grounds from the Boss amp (in the trunk) back to the Jenson. I was able to eliminate most of it by using one of those impedance transformers to convert the speaker leads into rca jacks which then went to the Boss amp. I was not able to use the pre-amp outputs from the Jenson radio. Anyway, now I have a Rockford Fosgate head unit with the same problem. I'm thinking of using a noise filter from Radio Shack in both the positive and negative leads from the radio. It appears that the stock radio must have some kind of noise filter that these after market radios don't have. Someone told me that the alternator is grounded to the bracket that it is mounted to. Is this true? And, can the alternator be grounded any better? Would this help? I know Richard Clark would have a long list of tests to perform to track down the source of the whining, but I don't understand why you can't just swap radios and be done with it.
REDS HOT AIR
Buick Tweaker
- Joined
- May 24, 2001
- Messages
- 3,433
make sure you have a good ground from the engine to chassis
make sure power wire running to the amp is not making contact with rca cords...normally run it down opposite side of car
if yo have any eq up front ground it to the head unit
basically it is most likely a grounding issue and you cant have to many grounds
do you have a ground from the body of the head unit to a ground? it may help
make sure power wire running to the amp is not making contact with rca cords...normally run it down opposite side of car
if yo have any eq up front ground it to the head unit
basically it is most likely a grounding issue and you cant have to many grounds
do you have a ground from the body of the head unit to a ground? it may help
First of all Red's mentioned that the ground in the front at the battery going to the chassis. For our car these ground is allways too small or not grounded properly.
If the ground is good and the noise is still there. I assume the Rockford deck has rca's. First start the car turn on the radio with the volume down, unplug the rca's going to the amp. Noise still there? No? Then you got a ground loop problem. Reground you head unit to a good ground point and every other accessories to it also, eq, crossorver, ect....Sometimes is good to run a extra wire to the amp preferbally a 14g, and ground it where the amps grounded also. If you unplug the rca's and the noise still there then it generated through your power wire, go to reroute the wire or could be a bad ground of the chassis or for the amp. Also check you gain levels, allways start off at center. Sometimes when I do a big system I encounter noise in the system and sometimes it a pain to figure out, most of the times I know its grounded good and its the car, so I pop in a ground loop isolator and this 75% correct the ground loop/noise issues. But "DO" not use inlie of the sub.
For the deck. Most manufactors of radio have a inline filter or its inside the deck/radio, so don't worry if you don't see it, unless its used and the other owner chopped it off.
For the alternator is grounded to the bracket. If this is bad then you will have other electrical problems. If you see on the ground side of the battery there is a thick guage wire going to the pass side of the block usually located below the turbo/heatshield bracket. You could check if its bolted to the block. Somethime in a rebuilt they forget to ground it.
If the ground is good and the noise is still there. I assume the Rockford deck has rca's. First start the car turn on the radio with the volume down, unplug the rca's going to the amp. Noise still there? No? Then you got a ground loop problem. Reground you head unit to a good ground point and every other accessories to it also, eq, crossorver, ect....Sometimes is good to run a extra wire to the amp preferbally a 14g, and ground it where the amps grounded also. If you unplug the rca's and the noise still there then it generated through your power wire, go to reroute the wire or could be a bad ground of the chassis or for the amp. Also check you gain levels, allways start off at center. Sometimes when I do a big system I encounter noise in the system and sometimes it a pain to figure out, most of the times I know its grounded good and its the car, so I pop in a ground loop isolator and this 75% correct the ground loop/noise issues. But "DO" not use inlie of the sub.
For the deck. Most manufactors of radio have a inline filter or its inside the deck/radio, so don't worry if you don't see it, unless its used and the other owner chopped it off.
For the alternator is grounded to the bracket. If this is bad then you will have other electrical problems. If you see on the ground side of the battery there is a thick guage wire going to the pass side of the block usually located below the turbo/heatshield bracket. You could check if its bolted to the block. Somethime in a rebuilt they forget to ground it.
As stated before I'm sire it's not the headunit. O my regal I redid all the wiring when I replaced my alternator. I put 4 gauge on everything from the battery to the alternator and grounds. I also put on a new grounding strap that runs from my frame to my engine block. I have Zero noises.
In my old GMC Jimmy I had a whine through my speakers also after I upgraded to a differnt headunit and put in an amp and a full range woofer box. This was installed at a sound shop, 1 year later I upgraded everything and put in new RCA's ( twisted pair) and that took away my problem.
In my old GMC Jimmy I had a whine through my speakers also after I upgraded to a differnt headunit and put in an amp and a full range woofer box. This was installed at a sound shop, 1 year later I upgraded everything and put in new RCA's ( twisted pair) and that took away my problem.
Those ground loop isolators do more just affect the bass sound, they affect the entire audio spectrum, subtle though it may be. If you are using good equipment you should NEVER need to use one of those. 99% of the time it is a ground loop or inductive noise (EMR). You need to have 1 reference to ground - and it should (will) always be the head unit. Every other component, including amplifiers, should have a very high impedance reading on the RCA's (pin and shield) to ground. EMR problems can ONLY be solved by re-routing the RCA cables away from the offending wires (or moving the offending wires). Sometimes even just moving the wires a little will eliminate this.
T
Turbo Dog
Guest
Thanks for all the good advice. Keep it coming. The power wires are run along the drivers side, and all speaker wires are run along the passenger side. I won't have much time to work on it this week, but I will try grounding the radio itself to something metal.
I always try to 100% isolate the low level signal wires. So, I'd put the power cable and speaker wires down the drivers side and RCA cables down the pass. side. The speaker wires will not inductively pick up any noise as long as they are run in a straight line. The only components that can inductively pick up noise are RCA cables AND inductors in crossovers. I don't think the speaker cables emit enough EMR to jump into the RCA's so your probably O.K. leaving them where they are at.
I agree, but the cheaper ones do alter the sound a little. But don't tell that to the SQ SQ SQ guys over on Sounddomain.com. They believe they can hear the difference in SQ between 2 different brand high end head units. They would tell you it can be heard. I laugh when I see those posts.
. I know those kind of guys are freaky sometimes. All wires can pick up inducted noise, any conductor in the presence of a EM field can get induced noise.
Speaker wires carry an amplified rca (low level) signal, so anything that gets 'induced' into the rca's is nothing to worry about.
The whole idea of moving RCA's away from power cable's is really quite pointless...where does the ground in your car connect? The chassis. What are your cables laying on? The chassis....see where I'm getting at?
You can't eliminate induced noise, what you have to do is make it to where both conductors in the rca's have EQUAL amounts of induced noise because amplifiers amplify the difference between the two.
Speaker wires carry an amplified rca (low level) signal, so anything that gets 'induced' into the rca's is nothing to worry about.
The whole idea of moving RCA's away from power cable's is really quite pointless...where does the ground in your car connect? The chassis. What are your cables laying on? The chassis....see where I'm getting at?
You can't eliminate induced noise, what you have to do is make it to where both conductors in the rca's have EQUAL amounts of induced noise because amplifiers amplify the difference between the two.
True, but when wire is wrapped in circles, ie a coil or inductor, it becomes much much much more sensitive to the noise. A straight piece of wire does pick up EMR but it is so slight it could never be heard by the human ear. But a crossover coil acts like an antenna and picks up even a small amount and transfers it.
Ya, but were not talking about a grounded surface. True, the body of your car is one big ground. There is not one spot that is conducting a large amount of current. We are talking about wires that are carrying either a high positive current or a high negative current. GM is famous for using marginal sized wires. I know on my TTA under the pass side of the dash there is a bundle of wires that is just loaded with EMR. If I put a pair of RCA's within a foot of this bundle I get a ton of engine whine. Solution, keep the wires away form it, no noise.
I worked at a shop in high school and first few years of college. My buddy owns the shop. He know in the area for doing high quaility work. He gets alot of re-installs from other shops for noise, hack work, etc. He still calls me every know and then when he can't find the sourec of the noise.
T
Turbo Dog
Guest
I know on my TTA under the pass side of the dash there is a bundle of wires that is just loaded with EMR. If I put a pair of RCA's within a foot of this bundle I get a ton of engine whine. Solution, keep the wires away form it, no noise.
GN and TTA- Is this bundle also on the GN? Could this be the source of my problem?
GN and TTA- Is this bundle also on the GN? Could this be the source of my problem?
T
Turbo Dog
Guest
I attached a wire to the back of the radio and grounded it to the metal frame where the radio bracket attaches to. It helped about 50 percent. Some whine is still there, but you can't hear it now with the radio on. Thanks for all the good advice.
If you are using RCA plugs maybe. But from what I read you are using speaker leads all the way to the back and then a line converter in the trunk, so I'd say probably no. But, there is only one way to find out, move them.
Good. If grounding the radio better helped, try this - unplug the antenna connector in back of the radio and see if the noise goes away even more, hopefully all of it.
If you still have noise after this you can do the ultimate test. This will 100% identify the problem. Get another car battery and put it in the trunk. Disconnect the power, ground, and power antenna lead from the amp and reconnect them to the extra battery. You have now gotten rid of any chance for a ground loop. Now power up the car and see what happens. If you still have noise with the antenna and amp isolated, your problem is in the radio or EMR through the speaker wires (doubtful) or maybe a bad line convertor.
I have an old boom box from the 80's with a pair of RCA inputs that I use for noise sniffing. Same idea, amp (in the boom box) is 100% isolated from car's electrical system being plugged into 110 volt electrical outlet. Put a pair of headphones on and you can hear even the slighest bit of noise.
T
Turbo Dog
Guest
I'm not using a line converter with the Rockford head unit. There is no whine with the engine off, if that helps at all. Do you think if I just run the ground wire from the radio to the trunk, that would eliminate the problem? When I grounded the radio to the bracket holding the alternator (just for kicks) there was still a lot of whine. When I grounded it to the metal where the radio mounts to, the whine was reduced. Seems like the further I ground it from the alternator, the better off I will be. How about if I run two ground wires to the radio? Would this help even more?
O.K. so from what I've read you are not using the RCA's correct? The Rockford HU is a quality brand, especially the pre-amp section. I would (if you haven't already) run RCA jacks down the OPPOSITE side of the power wire. Once you do that and have the RCA leads in the trunk, get an old 110 v stereo. As I said above, I use an old "boom box" but any stereo with an AUX input will work - home stereo for example. Hook up the RCA's to an AUX input on the stereo and get a pair of headphones and turn the volume all the way down. Start up the car, keep the volume on the Rockford all the way down, and put the headphones on. Slowly raise the volume on the stereo untill you hear noise. Some low frequency noise is normal. That is just garbage noise from other accesories. But you should not hear ANY whine at all. If you turn your turn signal on you will probably hear a clicking nosie in time with the signal flash. Again, completely normal. With the headphones on and volume turned up you are hearing things highly highly amplified. You will notice even moving the RCA's around a little will alter the volume of noise you hear. That's how I found the bundle of wire noise in the TTA.
I remember about 10 years ago we put a very big system in a Lexus. This guy had almost 2000 watts of real power. And it wasn't all bass. Can't remember exactly but probably 500 - 600 watts were for midrange and up only. I mean this car was LOUD and CLEAN. Anyway, the point is with all this power running upper range speakers, noise was an isssue. This guy paid some big cash for the system so we wanted it to be perfect. So I had to use these techniques to make sure the car was 100% noise free. And it was.
I remember about 10 years ago we put a very big system in a Lexus. This guy had almost 2000 watts of real power. And it wasn't all bass. Can't remember exactly but probably 500 - 600 watts were for midrange and up only. I mean this car was LOUD and CLEAN. Anyway, the point is with all this power running upper range speakers, noise was an isssue. This guy paid some big cash for the system so we wanted it to be perfect. So I had to use these techniques to make sure the car was 100% noise free. And it was.
T
Turbo Dog
Guest
I'm using the RCA "summed" outputs from the Rockford Fosgate head unit to the 450S Rockford Fos. amp in the trunk. This powers the Dayton 12 inch subwoofer. I'm also running the separate RCA outputs for the front and rear speakers from the Rockford Fosgate head unit to the Boss amp in the trunk. All RCA wires are run along the passenger side. Power wire is run along drivers side. Then I ran regular speaker wire from the Boss amp to the rear Eclipse 4X10's and also to the front 3.5 inch Alpines. Too bad I didn't get your address, GNand TTA, as I will be in Chicago tonight through Sunday. I'll use your suggestions next week when I get back to Champaign.
Thanks.
Rick
Thanks.
Rick
