I get the impression that everyone is all shits and giggles over Semi Rigid Fiberglass panels
I get the impression you haven't even done a search on it here to find out what has been posted in regards to it already.
Seems like anyone with a serious interest in something that applies to their studio would take time to address their curiosity by reading as much as they could to understand the question at hand.
But to address your question, you might want to know WHY rigid fiberglass does indeed work. Here is the general explanation.
Rigid fiberglass is referred to as a "resistive absorber". This is because, as
the air molecules move back and forth at a given frequency THROUGH the fiberglass, the fiber "interstices" place a resistance to this movement. This resistance transforms energy to heat. VOILA! Absorption. However, this takes place only because there is a boundary(wall) behind it. If there were no boundary, such as a wall, the sound would go THROUGH the panel, which would absorb very little, and continue on to oblivion, as in the case of an open window, which in reality is the PERFECT ABSORBER! But under the circumstances required by recording, who wants a bunch of open windows in thier studio. This boundary is what reflects the direction of the sound wave. But because there is zero velocity of the air molecules at a boundary, and maximum velocity at 1/4 wavelength, the standard explanation states that the thickness of the panel governs the lowest frequency it will absorb. More or less. Figure it like this.
A frequency of 100 hz has a wavelength of approx. 11.3 FEET. 1/4 of 11.3'
equals 2.8 feet. That is how thick the fiberglass would have to be to absorb down to 100 hz. Not very practical for low frequency. However, since there is zero motion of molecules at a boundary, it makes no sense to place the fiberglass directly against the boundary. Thats why it is recommended to set the fiberglass panel off of the boundary at least 1/2", as it is a waste of material to place it directly against it. Therefore, for a given thickness, you can lower the absorption frequency by leaving a airgap between the boundary and the fiberglass, which in effect, gives a greater distance between the face of the fiberglass and the boundary, as this distance is equal to 1/4 wavelength of a certain frequency, give or take. In a corner, this distance varies, which in effect gives a wider frequency band of absorption. You can simply place a panel of 2" to 4" across a corner of a room and it will perform perfectly.
And actually, peoply who place a frame around the edge of fiberglass panels, are removing some of the incident angle perfomance of the panel, as it absorbs even better for wavefronts entering at an angle to the panel. Tests have confirmed that panels whose edges are exposed , have a higher total absorption than those with edges covered. So, for those people who champher the edges of 3" or 4" thick panels, to make them flush at corner placement, or cover these edges with a frame, are actually reducing the performance of the absorber.
The performance of ANY fiberglass panel though, is also governed by its density. Normal fiber batt insulation has about a 1/3 density of Owens Corning 703, although batts come in varied densitys. Some types of rigid fiberglass, like OC 705, come with a membrane on one face, which I believe is aluminum, which also can improve absorption in the low end, and diffuse higher frequencys. BTW, this information has been posted here at least a dozen times. There is tons of information on this subject all over the net.
So, in regards to your use of the bolts, I would also be of the opinion that it will not perform the task of absorption, at least not in the proportion or frequency range that rigid fiberglass panels do.
Well, thats my .02 on this anyway. BTW, here is my disclaimer. I AM NOT AN EXPERT. Only a somewhat enlightened HR member. I only became enlightend to an extent by reading. Good luck with your fiberglass.
fitZ
Hey, I'm no expert - just trying to recall some things I've read about over the past few months 
Not to mention adults that post here, who fucked off their shool years and can't even read or write worth a shit . Tell ME that doesn't fucking exist HERE!!! Read a few of the the current threads on this bbs, and that should illustrate my point perfectly. Some of them I barely could read myself.
