Since dust collection noise can be irritating this may or may not be of interest to anyone but here goes for those of you who may be thinking about getting a vacuum for dust collection.
I did an on line search for decibel levels on Fein and Fastool vacuums. These are the levels listed on their websites.
Fein Turbo: lowest end model, $290, 66 dB
Festool: lowest end model, $400, low 62 dB, high 72 dB
I have two Oreck vacuums 80 dB
Filter Queen vacuum on my dust collector 65 dB
I mention the Filter Queen (FQ) because of it's power and low noise. I was perusing Craigslist and Facebook Market for used FQs. Facebook had a number of them from $25 to $250 with a lot of unneeded accessories. I've had two of them. They are very strong and new they are selling for over $3000. I bought mine perhaps 25 years ago used from a friend who was a dealer. I have a 13 gallon HF dust collector and the FQ works as well or better. Also the FQ is very compact and would work well for a stacked setup. So I am just suggesting checking out the used market and you may some money.