Source for a quiter muffler

[Cutting-edge]

Anyone know where I can find a quiter muffler designed to fit a B&S twin? I can get my welding/fab guy to build something custom but I was wondering.
Thanks

[CCWKen]

Be careful adding custom or additional fixtures to the exhaust. The engines are designed to use certain muflers. Adding more back pressure (needed to reduce noise) can cause burned exhaust valves and/or a poor running engine.

A better way to control noise would be to shield the muffler or it's directed exhaust. If you wrap "the can", leave the pipe alone.

[UNISCAPER]

If you take a Flowmaster from one side of a 350 cubic inch Chevy exhaust, modify the inlet for both pipes, the gears inside the engine will make more noise than the exhaust coming out. Our neighbor did that to his RV generator and you can't even hear the thing run.

[Cutting-edge]

I was thinking of building a collector and then a cheap muffler from Tractor Supply, aim the muffler down. I picked up one that's straight-through but thinking a multi-chamber would be quieter. I certainly would not think there would be any more backpressure using a muffler intended for a 3 or 4 cylinder tractor.
Thanks for the input.