Quieter muffler,,,yeah I know its not cool

[larksnostril]

I have an '81SH that I'm moving into a cafe configuration one step at a time. I don't like the stock mufflers looks. I also have hearing loss and tinnitus from the unbaffled drag pipes on my shovelhead chopper. I've been thru the 'louder is cheap insurance against cagers' and 'louder is cooler' phase and here I am not wanting to get deafer from riding.

So, the mufflers shown below have the look I want but I need to know if, compared to stock mufflers, are they louder, quieter or about the same? I'd love to hear from folks who know from direct comparison.

I also would like to achieve a more upswept look and would need to modify the existing headers or buy an extension of some type to make the curve upward. I want to retain the double walled headers and not just go to single walled custom headers.

Any advise is much appreciated.

 

[Tomterrific]

I know how you feel. My hearing is damaged from not knowing about hearing protection in factories, with guns and wind noise on the highway riding bikes for 45+ years. I've studied muffler design and I've come up with some simple facts.

A quiet muffler must be restrictive. FALSE! Read on.

Volume. The larger the volume, the quieter the muffler. What this means is a small muffler must be restrictive to be quiet but a large volume muffler can be just as quiet and still flow like crazy.

Shared mufflers. An XS650, most bikes really, look good with a muffler on each side. If a crossover pipe is added both mufflers share the acoustic pulse of each cylinder. This doubles the volume of the muffler system. But dosn't sound quite as good to me, a very small point.

Straight through glass packs. This design has the distinction of very free flow for the noise damping it gives. Volume must be large and the diameter of the perforated center pipe makes a difference. Smaller diameter equals quieter. One reason these types are so popular is that the fine wool packing damps most of the high frequencies so even a 50cc Honda sounds badass with a glass pack.

Tom

 

[scabber]

Mikes commando mufflers are real quiet but I don't hear that well.

 

[jamesgs4]

white mufflers in a snowbank?