Q) How can I connect/hook-up my computer to stadium sound systems?

  • A) There is no real easy answer, each situation is a little different.

 

The important thing to remember is that your PC's output is a line level output while most stadium sound systems only accept microphone level inputs.

Here is what works for me. I use the cables/adapters below to connect my laptop to a small field audio mixer (a Shure model 267, around $100.00 plus on Ebay). The Shure mixer has switchable inputs between mic and line level. The channel I use for my laptop is set to line level. The mixer's main output is also switchable between line and microphone level. I leave it at the microphone level and use a normal XLR microphone cable to connect to the sound system.

The main problem is that the output jack on your PC is a 1/8" mini jack while the input jack on the mixer is an XLR (Female). Here is where the cables come into play.

The first step is to use the "Y" cable (which comes with the Radio Shack Ground-Loop Isolator) which converts the 1/8" stereo output to two RCA jacks. This plugs into the jack on your PC.

The next step is to attach the Ground-Loop Isolator, note that is has two cables on it, a long one and a short one. You connect the SHORT one to the "Y" cable you just connected to your PC in the prior step.

The third step is to attach the RCA three phone plugs adapter to the LONG cable from the Ground-Loop Isolator. Remember that the output of your pc is stereo and this adapter converts it back to mono.

The fourth specialty cable has an RCA plug (Male) to an XLR plug (Male) that connects to the input XLR Female on the mixer. This cable is more difficult to find but is available on-line from several sources. I have included a link to a firm called Quality Electronics which does carry that cable. If they don't have it, use Google to search the internet for a RCA plug to XLR plug adapter cable.

1). Ground-Loop Isolator (Radio Shack part number 270-054. around $15.00), it comes with a 1/8" stereo plug to two RCA jacks "Y" cable.
2). RCA three phone plugs adapter (Radio Shack part number 274-511, around $2.50)
3). RCA phono plug (Male) to XLR (Male) cable (Quality Electronics part number XRM-110 RCA(M) to XLR(M), around $11.00)

And don't forget there are several other audio output possibilities in other FAQ's in the "Audio Outputs" section.


Why the Ground-Loop Isolator
It is quite common to experience a hum or transformer noise when you connect up various audio systems. The Ground-Loop Isolator eliminates that problem of a ground loop between your PC and the sound system. You can see further on buzz/hum advice in another FAQ.

Please remember that I am not an audio engineer and there may be a better way to accomplish this transition. This seems to work for me.

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What I currently use:

Whle the above will work great, This is the configuration that I currently use and have used for over three years now.

I connect an external sound card to the USB port of my laptop.  The one I use is the Edirol UA-1X, http://www.edirol.com/.

I then use a pair of RCA plugs to connect the Edirol external sound card to what is known as a Direct Box (or DI).  The one that I use is the Whirlwind PC-DI.

http://whirlwindusa.com/catalog/black-boxes-effects-and-dis/direct-boxes/pcdi

It is expensive (aound $130.00) but it is built like a tank and it is soliid.  It converts the line level output of the laptop to mic level.  It also has a gound lift which eliminates hum.

I then connect the Whirlwind PC-DI to one of the mic inputs on my Shure model 267 mixer using a three foot mic cable (purchased from the Guitar Center).  The output of my Shure mixer then connects to the input of the venues sound system using a standard mic cable.

Here is an article on what a direct box does:

http://whirlwindusa.com/support/tech-articles/direct-box-can-be-di-spensible/