View Full Version : Roxul ,Safe N Sound Insulation Being Used For quieting HP Air Handler

Mel Fulks
12-14-2015, 8:13 PM
When there is no need for thermal insulation, is there any value in compressing Roxul for more quieting?

Ralph Okonieski
12-14-2015, 9:44 PM
I do not know about compressing it. I used in in the ceiling of my basement shop where it works very well. Reduced the noise in the family room above it by a significant amount.

Mel Fulks
12-14-2015, 11:00 PM
Ralph, thanks. I've used it before just for thermal and noticed it did good job of quieting,too. I know that product density can be helpful in sound proofing. But I have no idea if compression is helpful with Roxul. Could be a long night of playing the stereo at top volumn, nailing up different thicknesses of Roxul over the windows ,then listening outdoors while recording data....how else can science advance!?

Allan Speers
12-14-2015, 11:45 PM
Compressing mineral wool, or any other semi-rigid insulation, will simply change the frequency that get most absorbed.

the typical 2-4 lbs per sq inch absorbs quite evenly from around 125 HZ to 8K or more. 5 lbs absorbs more energy in the 125 HZ range, less in the higher frequencies. So, if your machinery mostly rumbles at around 125 - 250 HZ, compressing would be a good idea. - Or leave it alone and add some sound board behind it.

note: You can squash it all day, but it still won't absorb much below 125HZ. For that, you need bass traps.

If you have any specific questions, feel free to ask & I'll help as I can. (time permitting.) I used to design recording studios for a living, and know this stuff inside-out.

Mel Fulks
12-15-2015, 1:50 PM
Allan, most kind and helpful and stated so I understand it. Thank you.