you may have accidentally misused the term 'bridged'. You don't want to bridge them, that's for sure. You will need surround speaker outputs from your soundcard or motherboard audio outs. These are usually 1/8" jacks. They are two in one meaning you will need to use a stereo jack to get the positive from each rear speaker. They share the negative pin. Look at your manual to see if your computer has a multichannel output. It may only be stereo. If it is stereo you will need to get a soundcard that has multichannel outputs.
When you get that far. This article will help you set up the rest of your system.
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