Audi RSF1

There have been cases where we tried re-grounding the factory radio or amp and found result. Not necessarily a fix in this case, but it is one of the many things that cause it. There are some cars out there that are just awful for aftermarket equipment, but ours are ok. Ultimately, putting a ground loop isolator can work, but only in a last case scenario when you are at your wits end. I never give up that easily, esp. when it requires down grading the signal.

HX_Guy

"A ground loop in the power or video signal occurs when some components in the same system are receiving its power from a different ground than other components, or the ground potential between two pieces of equipment is not identical. "

So basically because I don't have the amp grounded to the same ground as the HU or stock amp...that could be causing the ground loop?
Also it talks about "ground potential"...maybe my ground cable isn't big enough? It's a 10GA wire...should I try 8GA?

Can I pretty much rule out the line-level converer...or is that worth trying out as a possible solution?

Finally, how bad does a ground loop isolator regrade the signal? If its a quick fix, Im willing to try it. I'm tired of messing with this and having my trunk torn ot pieces.

NY-A4T03

U need a Cap

Audi RSF1

the 150, you would want to run 8 ga., esp. if you are bridging the amp (which it looks as if you are). Your quote is correct about how a ground loop can form. You can try ground the sub to the same point as the factory amp, but do not run your ground up front. You can try a temporary run to the factory amp ground, even if it is a couple of feet long, to prevent tearing everything up again.

As for the isolators, because they use tranfsomers to actuall break the signal, the signal can end up with either a voltage drop (forcing you to increase the gain on the amp)or worst case a slight amount of distortion added to the signal. Some listeners may notice it, some won't. There are isolators of varying degrees of quality, but the all ultimately do the same thing.

Here's the deal: in an ideal situation you would want to keep tinkering with the grounds until you fix it, but if you are done messing with it, try an isolator and see if you can live with it. At the very least, upgrade the wire to 8 ga. to help you amp out.

Bronze

metal ground, but I may be wrong. COuld this be an issue of ome amp being grounded to sheet metal, and the OEM amp being grounded to PWRGND (battery ground, signal ground, whichever name you prefer). The ground are eventually tied together, usually at the battery, but that may be too far away.

Since he replied to my note that he only hears it at engine running, and it increases with RPM, he's likely getting it from an engine-related, RPM driven component (tough search). So, the ground loop isolator may be the answer.

Interesting problem!

HX_Guy

Im thinking of just taking it all out and saying **** it. Too much of a headache.

I went with the 10GA becasue that is what the manual for the amp said to use. I already spent money on the 10GA kit, and since its all cut up, they won't accept it back for an exchange, I don't wanna lose more money.

I don't know...I'm bummed out. I went to the store to check on some ground loop isolators...they were between $35 - $70 depending on brand, Monster Cable being the $70 one. That's too much money to spend for something I'm not even sure I wanna have in the car (the subwoofer).

HX_Guy

By the way...where is the stock amp grounded?

Audi RSF1

I thought you were implying that it was smaller than your power wire. If you really want the sub, leave the wire in and start with the cheaper isolator you found. If the noise goes away and the signal sounds good, your set. There is nothing that you have to cut or modify on the isolator so if it does not help or degrades the quality there is no reason you can't return it. Unless you demand the highset quality of output, the isolator may work well enough to allow you to have the bass it sounds like you really want.

Audi RSF1

That pic was his original ground but he's changed it since.

Audi RSF1

Give me a sec. on this one.