Amp Question?

[who1975]

Hi everyone-

I just had a custom 10" shallow mount sub and JL amp to the sub and 4 door speakers installed in my 07 crewmax. My friend came over and helped me wire it all up. Everything works great and the sub is awesome for filling out the bottom. However, we ran into a problem with some buzzing in the speakers. My friend added some kind of line filter to the high/low box. We thought that it was fixed after doing that, but the buzzing has returned. What should I be looking for to get rid of the buzzing. When my friend touched the ground wires to the headunit, the sound went away. I thought he grounded the wires after the test, but do I need to do something different? Thanks in advance for any help.

Bill

[sic402]

Originally Posted by who1975;1335867[SIZE=4

When my friend touched the ground wires to the headunit, the sound went away. I thought he grounded the wires after the test, but do I need to do something different? Thanks in advance for any help.[/SIZE]

Bill

Wait what?

[who1975]

When he touches the ground ire to the headunit, the buzzing goes away. When you press on the gas petal, the whine gets louder.

[crash007]

Are the RCA cords running on the opposite side of the vehicle of the power wire? Try placing the ground in a different site. Make sure you sand the paint down where you place the ground wire for a good ground.

[who1975]

Ah yes, I know I read somewhere on this site that you need to run RCA opposite of the power. But, I forgot, and since my friend does this for a living, I assumed he knew what he was doing. The RCA cable runs on the same side as the power. I am not sure if I can move it to the other side. I will give it a try. I believe the ground for the amp is also on the same side. Is there anything I can do up at the headunit with the HI/lo box ground wire or the line filter ground wire? Thanks again for any help.

Bill

[who1975]

Quick update-

Moved the signal wires (both speaker and rca) to the opposite side of the truck and I am still getting the engine whine. In fact, I think it is worse now. I even get a weird buzz sound when I open and close the driver's door with the engine on. I did some more reading on the net and am wondering if I have created some kind of ground loop to get the alternator whine. Should I look into getting one of those ground loop isolators? Should I not have ground the in-line filter on the radio ground? I did sand the ground location down where the amp is grounded. Thanks in advance for any suggestions.

Bill

[dirtkid64]

You can buy a ground loop isolator at best buy or any store like radio shack. They don't cost much, I think mine set me back like $20. I had to buy one for my 3000 GT since the ground wasn't making that great of a connection. It just plugs up in your rca lines to your amplifier. Real easy and should take care of your problem.

[tundrunk]

that's interesting... did you mention your ground wire runs with your power wire? to get a better idea, wheres your amp and where does your ground connect to ground? for best results you want that ground wire to be short. my amp is in the rear compartment and the ground is 18" long, going into the floor with a self tapper.

[who1975]

My amp is in the very back behind the rear seat on the driver's side. The ground is connected to the floor with a self-tap screw by the pillar in-between the front and rear door on the driver's side. I even used a dremel to sand down the paint so I could be connected to bare metal. It is on the same side as the power wire. I am wondering more and more about the front tweeter speakers on top of the dash. Do they have separate speaker wires not connected to the two front door speakers. I have not yet tried to disconnect them and see if the humming sound goes away.

Also, I just put in a new headunit and the sound is still there. I have not tried the grounding of the RCA cable trick yet. Was hoping to not have to do that.

Bill

[tundrunk]

ok, so the ground should be fine. that is a bit of a head scratcher. it really sounds like a wiring issue but its hard to determine the culprit without being there. i would check all wires behind the head unit to be sure the strands aren't exposed in any way. if thats looking good, check the doors since you say it makes noise when you open/shut.
most of the time with component door speakers the wiring goes from the head to a small box which is a cross over, then from the box the wires run separately to the tweeter and the 6.5". not sure if toyota did it different but my 1st gen was that way.

[crash007]

So there are no power wires now where the RCAs are run? I would then try chosing a different ground point and sand it down really good so that no paint is showing (where you ground it) so you are going to get a good solid ground.

[tundrunk]

ever get this one figured out?

[who1975]

Not yet. Now I am getting some static sound out of the passenger front speaker. I am starting to think that I may need to re-wire the speakers to go back to the head unit and use the amp just for the sub. With the new Headunit, I am hoping 20 watts per channel should be plenty for what I listen to.

Bill

[tundrunk]

20 watts rms right? that should do fine. if you mean 20 watts peak, it will sound ok but distort fairly fast if you have the volume up high. mine is 50 watts peak/25watts rms per channel. i have it tuned to limit bass going through the doors and it can go pretty loud. especially playing rock music.

[who1975]

You are right. The new headunit is 20 watts with 50 watts max. I am just baffeled by the sound coming through the speakers. My friend is pretty knowledgeable and has done 100's of installs for customers with no problems. I have found that right now, I can not turn the volume up too much or my ears start to hurt. The amp that I have is super powerful. More powerful than what I need. thanks for your help.

Bill