Shop vacs ARE loud!
They are loud for 2 reasons, the type of fan used and the type of motor used, both of which make a lot of noise. Shop vac use AC/DC brush type motors like a Skil saw.
Dust collectors use different fans/blowers and induction motors, which are very quiet. So, you need a different type of suction system than a shop vac to collect the dust and chips. Then you need an air filtration system like an overhead Jet AFS1000 to collect the airborne dust.
Exhausting odors is a different technology, that collecting dust. You either replace the odoriferous air or clean/scrub it. Exchanging it is easier and cheaper than scrubbing it.
In my shop, I use 4 different systems ... air filtration, air exhaust, shop vacs and large Dust collectors. Each does one thing and does it better than the other. If I sprayed a lot of finishes, I would need an additional collection and filtration system dedicated to the spray area/booth.
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)