Thanks you TF I love your post always the cleanest work from you, and you solved what has been keeping me up for the past two nights.

Damn Airplanes!!!!
You're totally welcome. As I said before, glad to give back.

Your skills are extra ordinary.
Just lil ol me.:rauch08:

hey TF! any new news on this?
I haven't picked up that egg crate foam yet. I sourced it to walmart, I just don't go there barely ever. I do still need to build a couple more mufflers. At least I have the RTA ready for when I get my ass some foam. I will post up here then.

very nice TF. any suggestions for a 10 or 12?
Thanks Gator. As far as my mufflers, the outer tube is four inches bigger in diameter than the duct. I looked it up, and there is way larger available out there. Up to 24" on one manufacturer's site. You might need to go elsewhere than homey d's to pick em up though. Probably a brick and stone yard or concrete company would be the trick.

Hub and White Cap are 2 building supply stores that will carry the larger diameter tubes, for anyone thats interested. Have sizes as big as 36" at least.
great idea and looks like it works great!
I kept it simple, added carpet padding to up sized ducting (6" fan to 8" ducting, 8" fan 10" ducting, etc. but can go bigger if needed but doubt you will need to) took carpet padding and rolled it around the inside of solid 5' ducting after the fan. Used on 10" all the way down to 4" (4" being by far the loudest before i did this!) took the noise level from being heard from my basement room to me main floor living room to not any louder than a breeze you can here inside the room but not out.
Excellent! I just hung a 12" inline and it sounds like a Jet taking off. Also have 8" in our bedroom that makes it hard to sleep. Thanks for your post. Definite bump here but a good one.
I really like this muffler and want to do 3 of those! Is it safe to use poly-fil with hot air ? My fans move air from my wood stove heated basement, air is around 30 celsius I think. Thanks!
I used a dynamat type insulation to quiet things down alittle. There was a noticeable difference but it could always be better. Could do multiple layers but for now this is it.
Hiya folks...

I'm just building a small grow box, and I am not happy to hear that the Vortex fan is so noisy. But your advice here will help.

I have seen another posting somewhere using a box made of MDF to enclose the fan. If I can find the link, I'll post it.