# Ground loop with Crown XLS 2502



## Ifixtheinternet (Aug 28, 2015)

I just finished building my first subwoofer, a sealed Dayton UM18 mated with a Crown XLS 2502.

The sub is bringing a big smile to my face every day! 
However I seem to have a ground loop.

I have an Onkyo TX NR-646 AVR connected to the Crown with RCAs.

I'm hearing quite a bit of static through the 5 speakers, definitely audible from the listening position. 

This is present whether the amp is powered on or off.

If I unplug the power cable from the amp, the noise is gone.
If I leave the power connected but unplug the RCAs, the noise is gone.

So it seems to be just between the amp and AVR.
Both are plugged into the same power strip along with everything else.

Looking for any suggestions on how to fix it.
The AVR does not have balanced outputs, unfortunately.

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## theJman (Mar 3, 2012)

If the ground loop is being introduced by the cable TV system - and frequently it is - one of these might help.


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## Ifixtheinternet (Aug 28, 2015)

theJman said:


> If the ground loop is being introduced by the cable TV system - and frequently it is - one of these might help.


I only have an HD antenna connected to the TV on a 4 foot cable, no wall connection to coax, but I'll read up on this!

Will disconnect the antenna just to be sure though.


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## collo (Dec 23, 2006)

This might help Minimising Hum


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## Juan Acevedo (Jul 5, 2013)

Ifixtheinternet said:


> I just finished building my first subwoofer, a sealed Dayton UM18 mated with a Crown XLS 2502.
> 
> The sub is bringing a big smile to my face every day!
> However I seem to have a ground loop.
> ...


Several years ago I was using a Crown Xti for my subwoofers and I had hum problems.
I solved the problem by installing an ARTcessories DTI (Dual Transformer/Isolator)
This allows to have RCA to RCA, or RCA to XLR, or XLR to RCA, or XLR to XLR.
The Primary winding of the transformer is isolated from the secondary winding and thus the hum or ground loop is gone.


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## shene (Aug 3, 2014)

Ifixtheinternet said:


> I just finished building my first subwoofer, a sealed Dayton UM18 mated with a Crown XLS 2502.
> 
> The sub is bringing a big smile to my face every day!
> However I seem to have a ground loop.
> ...


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## shene (Aug 3, 2014)

First, try a "cheater plug" which bypasses the ground pin of the plug. If that does not work maybe a little device that is inserted in the audio interconnect chain. See amazon or google for a search for "ground loop eliminater" Most for a single line are about $6 to $12. 
( I am currently fighting ground loops and RF of a ham radio operator sneaking into my lines. ) Cheater plug should do it for under $1


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## SoundManDale (Oct 31, 2013)

The best soulition for Ground Loops is the Jensen Transformer Iso-Max





Home Theater | Jensen Transformers


There is nothing more frustrating than finally putting all the pieces of your home theater together, turning it on to watch your favorite movie and... all of a sudden, you are confronted with a terrible hum. In home audio systems, this is typically caused by the cable TV connection, less than...



www.jensen-transformers.com


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