Bass Hangers question

[Herwert]

Hello,

Thanks in for all the wonderful and very helpful information in this forum. It has been a great help!!

I have one question left on my bass hangers.

My bass hangers will be attached to the sloped (from 3 to 4 meters) ceiling. As ceiling below the hangers I will use an acoustic ceiling from Rockfon, the Opal with a overall absorption coefficient of 0.90 (0.39 0.77 0.88 0.80 0.92 0.87; www.rockfon.com ). What do you think of this choise?

I read about what should be around the MDF in the thread below:
http://johnlsayers.com/phpBB2/viewtopic ... &start=190

You are thaking about R11-fibreglass batt. I am not sure what that means. I presume 703 will be the best, but can I use normal very thick glass wool or rock wool? Since it must be only have to stop the low frequencies and the hangers must only be heavy? Or should it really be the material with the most high absorption factor there is (like 703)?

By the way 703 cannot be purchased in my country so I’m using an equivalent.

Thanks a lot for helping me out.
Kind regards Herwert.

[knightfly]

For hangers, heavier insulation isn't needed; the "R-11" designation is apparently not a worldwide spec, it refers to standard weight fiberglass insulation that is 3.5" thick (90mm), to be placed between 2x4 (35x90mm) studs in a wall frame. This insulation has typical density of just under 1 PCF, or 16 kG/m^3.

If you can find any standard household fiberglass insulation that comes close to those specs, it will work fine... Steve