Hi Lightnin, no I don't jest .... There are forums uncountable discussions on soundproofing for musical instruments, I have yet to see one post or manufacturer claim a 100% reduction in sound .... Even the reduction requires a booth to be 100% airtight.
I don't doubt you can do it for a router, and I would be pleased if it can be done
I don't know if a router when cutting is louder or quieter than a saxophone, I just thought it would be, judging from what I have heard from videos?
Judging a musical instrument and a router may have been unfair of me, you can't have an airtight box for a musician without specialized systems to get air in for the musician. Well actually you can, they are sometimes called coffins
So I am assuming that a router can run in an airtight box? and the actual sound is less than a sax (typically 94db)? What I heard from videos with a router cutting wood sounded as loud (or at least appeared to be) as a circular saw (typically 110db)?
If anyone wishes to build me a soundproof box, with a 100% reduction, or even 30-40db I will gladly pay a £1000. as long as the box doesn't over heat the router or damage it in any other way and it doesn't effect the running of the router