Well their each supercharger makes a unique sound,roots seem to whine,such as stock eaton,Centrifical (Procharger,Vortec) seem to have a diffrent sound...more like spooling of a turbo.My Procharger P1sc sounds great,has a sinister howl at Idel.When I get on it sounds almost like a turbo,with the BOV the supercharger sounds great...Also I picked up around 140 hp with it/and a 3 coor intercooler,at only 8 psi
Prochargers are loud as hell usually. I heard a vortech at only 6 or so lbs and it was noticable but nothing like the procharger I heard on a newer GT a while back.
V1 T-Trim's are loud as hell. They have straight cut gears (as opposed to the helical's in the V2's). You can hear one at idle from probably a football field away...
If I wanted loud I'd go with Procharger.
I like how quiet the new Powerdyne blowers are though, good for a sleeper.
But, then I like the numbers the procharger puts up vs. other blowers...
I would also have to say that the T-Trim and V-1 S-Trim with cog belt are very loud. I drove a 93 Cobra for about a year and a half through San Diego with a V-1 S-Trim and it would literally make everyone stop and watch as you drove by. Especially down town or under ground parking structures were the best.
The best part was when people would pull up at a light next to me and say how either my power steering was going out and that I should have it looked at or that something very serious was wrong with my car.
The best time ever was when this high dollar (all show I'm sure) import rolled up and the guy tried to bust on my ride in front of his girlfriend at a light and said it sounded like my power steering pump was shot and I should have it looked at. I replied, "thanks but the power steering is fine and so is the supercharger". The dumb ass look in his face was worth everything. Especially in front of his girl.