Wall insulation proyect... advice is welcome!

knightfly · Post by **knightfly** » Mon Nov 22, 2004 10:58 pm

Julián

For wall insulation, best results are with 2.5 to 4 PCF; to convert to kG/m^3, multiply by 16, so anywhere from 40kG to 64 kG will give the best results… Steve

Julián Fernández · Post by **Julián Fernández** » Mon Dec 13, 2004 12:45 pm

Thanks Guys! I have another question... I decided to build John´s Wall Units... ok now, how can i know which frecuencies to absorb? I mean, i understand how to use slat to absorb and reflect, but i don´t know which frecs. i´m supposing to avoid... (CR 2,4x2,9mts. * RR 2,9x4mts)
Can anyone help me?
Thanks!!!

knightfly · Post by **knightfly** » Tue Dec 14, 2004 8:44 am

Julian, I've yet to see a floor plan - are these rooms completely rectangular, with fixed ceiling height, or otherwise? Steve

Julián Fernández · Post by **Julián Fernández** » Tue Dec 14, 2004 10:30 am

Ops, sorry. Here it is. The ceiling raises from 8 to 11 feets (wood and roofing)...

knightfly · Post by **knightfly** » Tue Dec 14, 2004 6:02 pm

OK, are those measurements the INSIDE sizes, including ceiling height, between hard/solid surfaces? Steve

Julián Fernández · Post by **Julián Fernández** » Wed Dec 15, 2004 4:04 am

Yeah, those are the inside sizes... i mean, it´s the sizes of the naked room... (just the walls)

knightfly · Post by **knightfly** » Wed Dec 15, 2004 10:14 pm

OK, Julian - your CR is small enough that I'd not use much (if any) in the way of TUNED treatments - better to use broadband traps in the corners (thick fiberglas or rockwool, no slats) and the same at first reflection points, like on both sides of the mix desk where you've shown them; then hard floor and a "cloud" suspended over the mix table, leaving the rest of the room bright (no absorption) til you can listen and test, adding maybe bit more absorber surface if it's too bright.

Your live room, if it has to have parallel walls, should have patches of absorbent alternating on opposite walls (so the patches are not directly across from each other) - these should be anywhere from 2x2 foot to the full size of a batt (2x4 foot) and 3 or 4 inches thick; spacing them away from the wall a few inches will also help in the low mid frequency range.

This (alternating wass/absorber) will treat flutter between the parallel walls, and tame the brightness a bit; it will also help some of the "boxiness" of the room from too much mid frequency. If this isn't plain, ask and I'll explain further.

I would start (in the live room) by only doing two of the four corner traps you show. You can always add more if it's not enough, but there is no sense building things you don't need. You'll need the alternating absorbers on walls to kill flutter, and those will also work to bring down reverb time. Both your rooms are small enough you won't really have a "reverb time" as such, you're just trying to get the frequency response of the room more even.

If your ceiling in the live room is also sloped like the CR, I wouldn't put anything on it until you've heard how it sounds in recordings.

Hope this helps... Steve

Julián Fernández · Post by **Julián Fernández** » Sat Dec 18, 2004 12:39 pm

Thanks KF! Something like that? I can angle the walls, because i have the brick walls, but the inside walls are undone, so i can shape them as i want...
After angling the walls on the live room, should i treat them with aborbers?
And, yes, the room is sloped too... maybe for stetics reasons i´ll add an gypsum ceiling, but i´m not sure...
Any other thing to keep on mind?