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Discussion Starter · #1 ·
Since I can basically do whatever I want in the basement because my wife rocks, I'm not really holding back on sound treatment to get everything right. I have an area that meets the following criteria:

7' tall ceilings x 32' long x 12.5' wide​

Room Type
It's a fully in-ground basement with ground-level half windows scattered around the exterior cinderblock walls. WHen you walk downstairs, you walk into the finished portion which is the band room / theater / listening room. In the back corner of this room is a laundry room. Walking straight through the door into the theater room you can walk into the unfinished area which the oil tank, furnace, air handler, and fuse box. The theater room is not fully sealable at this point.​

Front, right side, and back walls are white painted cinderblock. Left wall is thin drywall (back side is open studs). The block in the rear is leaking slightly and needs to be fixed from the outside. i have three ceiling-height half windows.​

Poured concrete with drains underneath high traffic carpet. Not much foam. Large, high pile area rug covering listening area floor.​

Plasterboard with textured white finish. There's some unnecessary HVAC ducting that juts into your head clearance—with only 7' ceilings (rancher built in 1950) all that ducting is going to be removed and I'm going to redo the ceiling so it's flat throughout. The basement stays a comfortable temperature anyway in the summer so the vents down there are useless.​

Listening Position
12' from L/R speakers, center of chaise sofa​

Yesterday I took some measurements of the theater room and have some results to work with.

Here's what the room looks like... I'm sorry about the horrible lighting. I tried to bounce the flash a bit but the 7' low ceilings don't. Once the can lighting goes in the space will warm up significantly. Once you walk into the basement (door is just to the left in this pic) it open into the band space:

Looking right after exiting the basement door you see the theater area:

The UMIK-1 microphone was mounted in a mic stand, pointed straight up with windscreen on. Positioned at main listening position exactly.

I did three sweeps in each of the three configurations: all acoustic panels up, no acoustic panels, and corner panels only. For the SPL/frequency response graphs, I averaged the three sweeps for each configuration to try and even out an discrepancies between runs.

My interpretation of the graphs is that my panels have shortened the reverberation time above 100 Hz a bit, and very slightly flattened some response above 100 Hz. Remember, this is all straight out of the source with no EQ: receiver is set to Pure Direct.

Below 100 Hz, all three are practically the same. It sounds much different in-room when no panels are in it: I'm guessing that's the echos being reduced above 100 Hz. I've got a nasty null between 250–300 Hz, and a few bass frequencies (looks like 50 and 90 Hz) that are ringing fairly bad.

I'm going to need much more bass trapping and few more panels for the side and front walls.

Full Range SPL Comparison, 1/24 Smoothing
Full Range SPL Comparison, 1/24 Smoothing

Bass SPL Comparison, 1/48 Smoothing

Full Range Waterfall, All Panels, 1/24 Smoothing

Full Range Waterfall, Corners Panels Only, 1/24 Smoothing

Full Range Waterfall, No Panels, 1/24 Smoothing

Bass Waterfall, All Panels, 1/48 Smoothing

Bass Waterfall, Corner Panels Only, 1/48 Smoothing

Bass Waterfall, No Panels, 1/48 Smoothing
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