703/705 with or w/out FRK for drop ceiling

[rjaudio]

Hi All,

I'm in the process of treating a room to be used only for post production (no recording). It's fairly large, 15' x 25'. The only issue is the ceiling which is a drop ceiling 7' from the floor. I'd like to replace the standard tiles with either 2" 703 or 705 and have some questions before I proceed:

1. Is 703 rigid enough (2'x4' tiles) or should I go with 705?

2. Do I get them with FRK, without, or a combination? I'm thinking the area above the mix position and speakers should be without, but what about the rest of the ceiling?

3. I'll also be treating the first reflection points (without FRK) and then building some trapping by putting two panels together for 4" of thickness. Should the traps have FRK on the front?

The walls are sheetrock, the floor is carpet over a slap. My monitors are large full range speakers so bass trapping is of great importance. I want to make sure I add enough bass trapping without making the room too dead sounding.

Thanks in advance.

Jeff

[Glenn Kuras]

1. Is 703 rigid enough (2'x4' tiles) or should I go with 705?

Yes

2. Do I get them with FRK, without, or a combination? I'm thinking the area above the mix position and speakers should be without, but what about the rest of the ceiling?

Do not use FRK on the ceiling above the mix spot. You want to absorb the high end which FRK will reflect it. The rest of the room depends on how much life you want to keep.

3. I'll also be treating the first reflection points (without FRK) and then building some trapping by putting two panels together for 4" of thickness. Should the traps have FRK on the front?

Yes for bass trapping use the FRK on the fronts.

Glenn

[rjaudio]

Thanks for your reply.

yes to 703 or 705? I know from Ethan's tests that 705 is slightly better but it is also more $; $.90 versus $1.30 sq/ft. for 2". I'm actually quite happy with the liveness of the room right now (excluding the bass issues) so I'd like to keep that. I guess I can always try it with the FRK around the perimeter and if it's too much peel it off or flip the panels.

Any way to use the cavity (about 5") above the drop ceiling as one big bass trap?

Jeff

[Glenn Kuras]

Originally Posted by JeffK

Thanks for your reply.

yes to 703 or 705?


Jeff

Yes to 703.

Any way to use the cavity (about 5") above the drop ceiling as one big bass trap?

Sure fill it with more 703 or fluffy fiberglass.

Glenn