Exhaust Questions

Hello again! Thanks to all who helped me with my last post. My closet is up and running, but the 6" inline fan I installed is too loud. It is on all the time because I am using a 400 W HPS.

I was wondering what would be the quietest fan of the best VALUE?

Thanks!

THEY MAKE MUFFLERS! I run a 8 inch vortex with a muffler it is almost silent. i had to make a rubber boot to stop vibration when it was in my attic