I have searched for a quieter shop vac but have not found one that's good enough. One of the members in the Community Forum pointed out these three videos showing the construction of a shop vac silencer box.
To me this looks like a possibility but I have some reservations about heat build up. For normal clean up I think there would not be a problem but for extended cutting I wonder how hot the unit would get.
I would like to hear from some industry people what they think about using this type of system for long sessions. If you have built a similar system and are currently using if for scroll saw dust collection email me with your opinions.