Originally Posted by Kara Chaffee
... the Helmholz resonance of my helmet...

Does it make a difference who made them?...

Evening Kara - I've never heard of this, could you say some more about it please? I'm curious because occasionally, I have experienced a weird sound in my helmet, a bit like Indonesian music if that means anything? Could this be that? (I do have loud exhausts).

Also, I believe manufacturer can make a big difference. Someone else mentioned Campbells silencers. I had a pair on a T140 I bought cheap 30-odd years ago. it was cheap because it wouldn't do more than 80mph. I took the very nicely made and very nicely chromed Campbell silencers off and it went like a rocket - back to better than normal in an instant (normal being with the quiet 'cigar' type silencers).

Those 'cigar' type silencers are also restrictive and knock a good 15% of power off, at a guess based on what the difference feels like. But they are a lot better than Campbells. Should have stuck to making soup.

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