Questions about materials etc...

[Sepe]

Nice forum u got here! Already found a lot of interesting stuff...

Now, I have some very rigid mineralfiber pieces with density close to 140-150kg/m3. Link: Paroc FPS14

Are these usable for any kind of bass absortionpanels?


My second question would be: My quite odd-shaped little controlroom (see attachment) is wider from the other end. Which end would you use for monitoring? It is also somewhat higher on the wide end.

I have very good balance in the room, but a HUGE 15db dip 'round 65-85hz. I do have massive "cornerchunks?" of 35-40kg/m3 mineralfiber in every corner, from floor to ceiling. Not much more of anything yet. Still studying this.

This was planned to be a practiceroom, but it will be a controlroom now

Thanks for any advice in advance...

Sepe, Finland

[jhbrandt]

Sepe,

Welcome!

The 140kg/m3 stuff will work.. but in general it is too dense. You could make bass traps with them straddling the corners and covering them with the lighter stuff. This may work well without filling the corner like a super chunk. - Also hang a couple pieces of these vertically in the corner behind the trap dividing the space into 3 sections.

Most likely, much more treatment is needed; Test and move forwards and backwards to find the best spot for mixing... to get out of the null. Or the null could be due to SBIR.. try moving the speakers closer to the wall - or further away. Do this to obtain the smoothest LF response at the listening position. (Try playing some sine sweeps. The position of the peaks and nulls will quickly become evident)

More information is available on my publications page and at the Realtraps site and GIK site.

Cheers,
John

[Sepe]

Thank you very much! I will make loads of absorbers and then start experimenting with your mentioned things.

I have no problem with having to lose some space, (because of basstrapping) from this already small room, so I started to build these simple 100mm broadband absorbers.

Since they are only operating maybe 120hz-****hz area, I wanted to ask if there is a way to build somekind of larger absorber to, lets say 60-120 area?

I do have materials to build f.ex. thick paneltraps with rubber(vinyl) membranes, but I find no info about how broad/narrowband I can expect them to become....

Maybe it would be wise to build somekind of huge really thick and full height bass absorbing "closet" in the back of the controlroom?

A thing about this building also is, that it is in cold Finland, and is built with 2011 energy saving regulations, so the outer walls are made of
2x 13mm gypsum + 300mm insulation etc.
Here is a picture of the structure.
I dont know if f.ex the whole building acts as an absorber for low bass allready... through the 26mm gypsum.