Need some techinal back up

Post by **mr tibbs** » Wed Apr 01, 2009 10:18 am

I'm chasing down a ground loop in the FJ. Today I started by upgrading the power and the ground to the head unit with 12 gauge directly to the battery. That didn't solve it. Next I checked the RCA's. With the FJ running and the headunit on with volume at zero I had the alt whine. When I unplugged the RCA's the alt whine went away. So, I assume the RCA's are not picking up noise. Next I went and grabbed a different pair of RCA's and went directly from the headunit to the amp bypassing the SLD44. With the FJ running and the headunit on with the volume at zero I had no alt whine.

So, I'm assuming my problem is the ground for the SLD44. Does this sound right??

Post by **AVICJR** » Wed Apr 01, 2009 10:25 am

By process of elimination sounds like it may be the problem or in line of the problem. Can you run another set of RCA's to the SLD from HU then test, if not problem run another set from SLD to amps then test?

Post by **mr tibbs** » Wed Apr 01, 2009 10:31 am

AVICJR wrote:By process of elimination sounds like it may be the problem or in line of the problem. Can you run another set of RCA's to the SLD from HU then test, if not problem run another set from SLD to amps then test?

I could, but I thought I eliminated that by unplugging the RCA's while the engine was running and getting no noise. Doesn't that mean that the RCA's are not picking up noise? I'll go try both after lunch and let you guys know.

Post by **mr tibbs** » Wed Apr 01, 2009 10:33 am

Also, I just thought of the fact that I had alt whine before with the stock headunit adn I was running the SLD44 off of the high inputs so there were no RCA's going from the headunit to the line driver so I don't think that is the problem either.

Post by **mr tibbs** » Wed Apr 01, 2009 11:10 am

OK, I just went and tried to replace the RCA's first from the line driver to the amp then from the headunit to the line driver. The alt whine is still there. This is telling me I have a ground issue somewhere and the RCA's are not picking up noise correct?

dBincognito · Post by **dBincognito** » Wed Apr 01, 2009 11:21 am

Do all of your grounds run off a distro-block or do you have seperate grounds for everything ?

Does your ground run straight from the battery ?
Or did you ground at the nearest location to the amp ?

Post by **mr tibbs** » Wed Apr 01, 2009 11:31 am

Well, now the line driver and the HU are grounded directly to the battery. The amp was grounded on the chassis with a jumper to the frame, no distro block.

I just grounded the line driver directly to the battery and the alt whin eis still there. I really hope it's not the amp ground. I really don't want to buy 1/0 to go all the way back to the battery.

Jim Truett · Post by **Jim Truett** » Wed Apr 01, 2009 11:55 am

Classic ground loop. Connect the ground for the LD and the Deck at the same location as the amp.

dBincognito · Post by **dBincognito** » Wed Apr 01, 2009 11:58 am

Jim Truett wrote:Classic ground loop. Connect the ground for the LD and the Deck at the same location as the amp.

That's what I was getting at.....you should have 1 main ground that runs to a distro-block and goes to all sources

I never have any problems when I do it this way

Post by **mr tibbs** » Wed Apr 01, 2009 12:09 pm

Jim Truett wrote:Classic ground loop. Connect the ground for the LD and the Deck at the same location as the amp.

I just tried this, there is still noise. It has to be the line driver introducing noise. I'm gonna go buy some RCA "butt" connectors and take out the line driver completely.

dBincognito · Post by **dBincognito** » Wed Apr 01, 2009 12:14 pm

mr tibbs wrote:
Jim Truett wrote:Classic ground loop. Connect the ground for the LD and the Deck at the same location as the amp.
I just tried this, there is still noise. It has to be the line driver introducing noise. I'm gonna go buy some RCA "butt" connectors and take out the line driver completely.

Is the line driver new ?

Post by **kg1961** » Wed Apr 01, 2009 12:32 pm

are the speaker wire running beside the power?

Post by **mr tibbs** » Wed Apr 01, 2009 1:07 pm

dBincognito wrote:
mr tibbs wrote:
Jim Truett wrote:Classic ground loop. Connect the ground for the LD and the Deck at the same location as the amp.
I just tried this, there is still noise. It has to be the line driver introducing noise. I'm gonna go buy some RCA "butt" connectors and take out the line driver completely.
Is the line driver new ?

Nope, I have been using it for close to a year now. But, I was using it as a LOC, not a line driver.

kg1961 wrote:are the speaker wire running beside the power?

Nope, I made sure of this in this install. Speaker wires are run down one side, power on the other and the RCA's straight up the center console.

Well, as soon as I bypassed the SLD44 there is no noise anymore. I just went and bought some RCA "butt" connectors and joined the RCA's that were already run through the car. Now there is zero noise. I'll set my gains on the amp and call it a day for now. In the near future I will have to run new RCA's and get rid of the "but" connector, but for now it will do. No more line driver for me!

waynehead · Post by **waynehead** » Wed Apr 01, 2009 1:24 pm

Im glad you came to a conclusion and fixed it but Im sad that you have no line driver now. I was very impressed with just raising my voltage to about 2 volts, so much that I will probably never go without one. Hows the FJ sounding now-a-days.? I really like the way those are built and I would think they are deadeneds pretty well from the factory. Didnt you put components in it recently or am I thinking of someone else?

Post by **mr tibbs** » Wed Apr 01, 2009 1:50 pm

waynehead wrote:Im glad you came to a conclusion and fixed it but Im sad that you have no line driver now. I was very impressed with just raising my voltage to about 2 volts, so much that I will probably never go without one. Hows the FJ sounding now-a-days.? I really like the way those are built and I would think they are deadeneds pretty well from the factory. Didnt you put components in it recently or am I thinking of someone else?

Actually this was the first time I had ever used a line driver so I guess I won't know what I am missing.

The FJ sounds good now! And yes, I am about to install some new comps into it. I seriously can't wait to get the Ultra's in there now that I have a real headunit.

dBincognito · Post by **dBincognito** » Wed Apr 01, 2009 3:33 pm

waynehead wrote:Im glad you came to a conclusion and fixed it but Im sad that you have no line driver now. I was very impressed with just raising my voltage to about 2 volts, so much that I will probably never go without one. Hows the FJ sounding now-a-days.? I really like the way those are built and I would think they are deadeneds pretty well from the factory. Didnt you put components in it recently or am I thinking of someone else?

With the deck he is using, he really will not benefit much from a line driver anyway...as the voltage is already 5 volts coming out of the deck on the RCA's

gkitching · Post by **gkitching** » Wed Apr 01, 2009 4:13 pm

Could be your line driver is picking up noise from something in the immediate vicinity of it's mounting location. Some strong power or ground source. If you had some slack on the wiring, you could pull it out or move it around to see if the noise comes and goes.

Post by **mr tibbs** » Wed Apr 01, 2009 5:07 pm

gkitching wrote:Could be your line driver is picking up noise from something in the immediate vicinity of it's mounting location. Some strong power or ground source. If you had some slack on the wiring, you could pull it out or move it around to see if the noise comes and goes.

I guess I could have tried that before I ripped it out. Now, not so much.

Post by **Bfowler** » Wed Apr 01, 2009 5:11 pm

dBincognito wrote:
waynehead wrote:Im glad you came to a conclusion and fixed it but Im sad that you have no line driver now. I was very impressed with just raising my voltage to about 2 volts, so much that I will probably never go without one. Hows the FJ sounding now-a-days.? I really like the way those are built and I would think they are deadeneds pretty well from the factory. Didnt you put components in it recently or am I thinking of someone else?
With the deck he is using, he really will not benefit much from a line driver anyway...as the voltage is already 5 volts coming out of the deck on the RCA's

casey, Arent you using a xenon 200.4? if so...you do have a lot to gain from a line driver. they are happy around 10, and will take up to 13volts.

Post by **mr tibbs** » Wed Apr 01, 2009 5:20 pm

Yeah, that's kinda what i was thinking, but if it's gonna induce noise then it's not really worth it to me. I turned up the gain and just kinda set it by ear for the ride home and it seemed to be ok. Tomorrow I'll get the DMM out and set it correctly and see where I am.

Need some techinal back up

Need some techinal back up

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