Amp turn on wire whine

[WhiteYota]

One thing I have not tried is running a new ground for the HU, it is still using the factory ground wire in the harness. I have never had a problem using them so I didnt think it would be an issue. But like what was said earlier is that the issue is only there with the sub amp connected so I dont think it is that either.

 

[los33 10+ year member]

Don't recall the reasoning behind it exactly, but I can look into it. Have read it many times before and my installer has also advised that.

Not attacking you, but you arent the only one who has said that and some tests have been made and still not fully confirmed.

Love to hear why tho.

Sent from my Z970 using Tapatalk

 

[fly_marlin]

Separate grounds and another set RCAs for the sub amp is the only thing I can think of left to try. Someone else suggested the amp could be the problem, but I hope it isn't. Too much hassle.

 

[WhiteYota]

Separate grounds and another set RCAs for the sub amp is the only thing I can think of left to try. Someone else suggested the amp could be the problem, but I hope it isn't. Too much hassle.

That is kinda my reasoning behind trying to get other peoples ideas on this. I do not exactly have another 800$ to spend on another amp and I do not want to send it in for warranty for them to tell me it checks out fine only to find out it was something small I overlooked.

 

[fly_marlin]

I don't know much about these things, but some people use them. Seems like a pretty cheap and simple solution, if does indeed work:

PAC SNI-1 RCA Ground Loop Noise Isolator at Crutchfield.com

 

[LosIsATool 5,000+ posts]

I don't know much about these things, but some people use them. Seems like a pretty cheap and simple solution, if does indeed work:
PAC SNI-1 RCA Ground Loop Noise Isolator at Crutchfield.com

Those rarely work. It's normally just a bad ground or gains to high.

 

[Bossman150]

That is kinda my reasoning behind trying to get other peoples ideas on this. I do not exactly have another 800$ to spend on another amp and I do not want to send it in for warranty for them to tell me it checks out fine only to find out it was something small I overlooked.

Just an FYI I just had to send back an amp for noise, I was convinced it was not the amp until they swapped my old amp back in and the noise was completely gone. Mine was alternator whine and I am still not quite sure how an amp could cause that but since switching out the amp fixed it I guess its hard to argue with. It was also making a wierd noise on power off.

 

[WhiteYota]

EDIT: Sounds like a problem with the HU. You did the right thing checking the fuse on the RCA shields but when you grounded the RCA shields, did you do it at the amp or the HU? You should do that at the HU, at the amp won't help. The amp usually ties the shields to the secondary center tap of the transformer and that is usually tied to ground with a 1Kohm resistor and a ceramic capacitor.

I checked this and it is open between the outer RCA terminal at the amp and the amp chassis, not even a slight bit then to infinite like when checking a cap.

I also did check the neg power cable and it is directly connected to the amp chassis (reading of 0.02 ohms which could be the leads on my meter). Could the amp be using a balanced RCA input and could that be the cause of the noise?

EDIT: I checked it with the system power on and it is connected, has about 800 ohms. Weird that it only connects it when it is powered up.

My meter is not an auto select (TPI brand I bought with the electronics test kit when I was at school), even on the highest(20M) scale it was open.

try unmounting your 3800.1 and place it on a piece of wood to see if you still have the issue.

I unmounted it and placed cardboard under each of the brackets to isolate the amp from ground and the whine/hiss got louder.

EDIT: Ok my bad - it does NOT get louder, must be cuz I was in the back of the van and the whine is louder there. But isolating the amp did not effect the whine in any way.

I am still not sure what part to blame so if anyone has some suggestions I would be more then willing to try it.

 

[fly_marlin]

Did you try a separate ground with a new ground wire? Bad wire can have an effect.

 

[WhiteYota]

Did you try a separate ground with a new ground wire? Bad wire can have an effect.

On the amp or the HU?

I have not made it to the HU ground yet, that is next.

I am really doubting that the amp ground wire could be it. All brand new 1/0 OFC wire.

 

[fly_marlin]

Well, like I said, I was always advised to have separate ground for all amps...

 

[ChaseinBass]

Only out of highs. I did some more checking and listening - I do not think it is alt whine. The whine does not respond as fast as engine rpms do. I have had alt whine in another car and this does not go up and down as fast with engine rpms as that other car did. I also tried putting in a relay into the rem line to the amps and that made no difference. I did disconnect the 3800 and the whine went away. I was just thinking - where I put in nut inserts into the body for the ground, I looked at an extra and noticed they are aluminum inserts.

In case anyone is wondering what a nut insert is - Drill a hole that is the same size as the insert, then with the tool for them - it collapses the insert sandwiching the sheet metal in between it. The ones I used are for 3/8" bolts - put a bolt into it with the grounds and tighten it up. No worries about it becoming loose.

Here is one of the ones I used

Hey can you show me the nutcert tool you are using ? pic dont work ? I bought the cheap one at harbor freight and it ***** and want to get a good one.

 

[WhiteYota]

Ok so the ground to the HU is not a problem - just ran a direct wire to batt ground and no difference at all.

Well, like I said, I was always advised to have separate ground for all amps...

I can kinda see where you are coming from with it but only if I was pushing the amps where the single ground connection could not carry the amperage. To me, spacing out the ground points would be like adding another run of power cable. You are only going to have battery voltage but it does increase the load capacity. I would see it as the same with grounds, but the frame of a car is definitely going to carry wayyyyy more then any cable you hook up to it will where it is just a very large buss bar.

 

[WhiteYota]

Hey can you show me the nutcert tool you are using ? pic dont work ? I bought the cheap one at harbor freight and it ***** and want to get a good one.

Sorry, I moved the pic to an album and forgot to update the link, updated now.

The tool I used is a snap-on set that was made before harbor freight was even thought of. My dad has been in auto repair since the mid 70's.

I also wrenched on them really good when I tightened the hold down bolt. Also re-checked them and they are still really tight.

EDIT: I checked snap-on website and they do not make it anymore. But I will mention that good tools are not very cheep so if you can find someone who has a good quality tool that you can borrow would be your best bet.

Here is a link to one like what I used - Nutsert Tool. Lawson makes very good quality stuff but wants like 200$ for the tool though.