[ict_Lx]

Ok, here's one for you guys. I just finished installing my amp. It is a 5 channel pyle amp 1400 watts. I also installed my two 12" JBL Subs in my homemade box. Now for the problems, I have two. First of all, after everything was hooked up, I took the car out for a test drive. I noticed a very annoying whining sound that gets louder as the rpm's go up and falls as the rpm's fall :angry: . The second problem is that with the trunk closed, my subs sound distorted and muffled. With the trunk open they sound awesome with no distortion. Between these two issues I'm not very pleased with my install. I almost wish I had just paid the $175 that the audio shop wanted for the amp install. Then they could have worried about it. If anyone has any suggestions I would really appreciate it. Thanks in advance.

-Scott

 

[XLSuruaT]

Are you running your rca cable on the same side as your power cable?

 

[silvapain]

I noticed a very annoying whining sound that gets louder as the rpm's go up and falls as the rpm's fall

That's alternator whine. follow XLsuruaT's instructions and run the RCA's down the opposite side as the power bundle.

with the trunk closed, my subs sound distorted and muffled. With the trunk open they sound awesome with no distortion.

Which way are the subs firing? They should fire towards the back of the trunk.

 

[ict_Lx]

Originally posted by XLSuruaT@Aug 3 2004, 12:25 AM
Are you running your rca cable on the same side as your power cable?

The RCA are run from the factory JBL sub to the amp through a LOC. Everything is kind of in a mess of wires right now because I still have my back seat out and have not mounted the amp yet.

 

[ict_Lx]

Originally posted by silvapain@Aug 3 2004, 02:19 AM
Which way are the subs firing? They should fire towards the back of the trunk.

The subs are firing towards the back. At one point I thought it might be because I have a homemade box but then decided that wasn't it. If it was the box, it would sound crappy all the time.

 

[ict_Lx]

Update: I disconnected the rca's and the whining sound did not go away. Could the problem be because I hooked up the power at the fuse box in the engine bay on the same line that powers the alternator? I may try disconnecting that and attaching it directly to the battery terminal.

 

[silvapain]

That's exactly the problem. The power lines for the amp need to go directly to the battery.

 

[ict_Lx]

Grrrr...That's upsetting. I got that idea from the writeup on V8sho.com...I would have never thought to put it there on my own. Hopefully that fixes that problem. Now to figure out those subs...Thanks.

-Scott

 

[ict_Lx]

I just finished unhooking the power line from the fuse box and hooking it back up to battery. I started the car and it was still making that whining sound :angry: . Does anyone have any other ideas?

 

[moneyshot]

check your wiring and make sure there isn't a partial short anywhere.


also check your ground??? did you run the ground up to the battery or have a solid connection to the panel you attached it too?

 

[ict_Lx]

The ground is attached to the seat belt bolt for the back seat.

 

[taurus2000]

Originally posted by Ict_Lx@Aug 3 2004, 02:14 PM
The ground is attached to the seat belt bolt for the back seat.

Is the seat bolt attached to the chassis of the car. If it's not, you should attach the ground to the clean (shiny) metal chassis piece. My system didn't work at all until I grounded the amp to a bolt that connected to the chassis.

Good Luck

 

[ict_Lx]

That will be the next thing that I will try. I really don't want to take it up to the audio shop. I know they will charge an arm and a leg. Plus I think I will have to go up there to figure out the sub issue.

 

[moneyshot]

the sub issue might just be somehting with your subs the right distance away from the deck lid and the waves bouncing off the lid and back into the trunk might be causing the distortion.

i order to fix that you might have to mat your trunk deck with sound deadener.

 

[golovko]

Get some low grit sandpaper or steel wool and sand the **** out of the surface you attach your ground to and try to make it less than 2 feet if possible, the shorter the ground the better.

 

[Ryne]

try tuning the amp to the subs with the trunk lid closed... that might take care of the bad sound quality.

 

[sixfofalcon]

The whining noise is b/c of a ground loop issue. You can purchase a "ground loop isolator" from Rat Shack for <$20 and install it inline on the RCAs. If you don't want to do that, run a small wire (18AWG is fine) from the RCU or head unit housing to the amp housing. There should be a small Phillips screw right above the RCA jacks on the amp specifically for this purpose. This resolves the issue of having excessive resistance between the signal source and the amplifier.

That's exactly the problem. The power lines for the amp need to go directly to the battery.

And that won't make any difference. The battery is connected directly to the alternator, so connecting directly to the battery will still pick up RF noise from the alternator.

 

[ict_Lx]

The sound is still there when the RCA's are disconnected. I moved the ground to the side wall of the trunk. Are all grounds created equal as long as it works? I'm going to move the power cable back to the fuse box because it is more conveinent than the battery.

 

[ict_Lx]

Originally posted by MoNeYsHoT@Aug 3 2004, 02:32 PM
i order to fix that you might have to mat your trunk deck with sound deadener.

I just bought a dynomat trunk kit. Hopefully that will help things once it is installed.

 

[silvapain]

Originally posted by Ict_Lx@Aug 3 2004, 05:01 PM
Are all grounds created equal as long as it works?

No. The ground needs to be the same gauge as the power or larger. It needs to be 18" MAX to reduce resistance. It needs to go directly to the frame, And it needs to go to bare metal.