does any1 has...

[fritzdam51711]

a circuit on surround sound amplifier or an amplifier with an output of 4 channels and a subwoofer

 

[Nigel Goodwin]

a circuit on surround sound amplifier or an amplifier with an output of 4 channels and a subwoofer

Subwoofers are common place, and can easily be connected to either mono or stereo sources - but 'surround' is a different matter. There have been various useless systems other the years, but the only two really worth mentioning are Dolby ProLogic, and Dolby 5.1, both of which require suitable signals.

Prologic encodes the surround on two normal stereo analogue signals, so can work via any stereo signal - if it includes the coded data?. There have been various DIY ProLogic systems over the years, but they are expensive and complicated.

5.1 is a digital system, usually on DVD (although occasionally on Digital TV as well) - the 5.1 decoder is usually inside the DVD, which provides outputs for 6 audio channels. If it's not got a built-in decoder, it will probably have a digital output (either phone or optical) which you can connect to an external decoder.

So waht are you wanting?, and what are you expecting from it?.