And the results of Frank's hard work are in! . . .
OK, I'll do this in sets of three graphs. Each set of three shows first the original empty, untreated room. Then the situation we were at before these new poly-slat-walls went in, and finally the situation now, with the poly-slats completed.
So firstly, the RT60 graphs...
Frank-REW-RT---Baseline-Empty.png
Frank-REW-RT---1-mil-and-6-mil-plastic-strips--3.png
Frank-REW-RT---PolySlotWalls.png
Not much comment is needed for those three! The improvement is drastic, and clear. Originally the room was off the charts, then way too dead, and now it is is nicely live again.
Next, the waterfall plots for the low end of the spectrum (most critical):
Frank-REW-WF--18-500---Baseline-Empty.png
Frank-REW-WF--18-500---1-mil-and-6-mil-plastic-strips.png
Frank-REW-WF--18-500---PolySlotWalls.png
Here too the improvement is rather obvious: It is very clearly a lot smoother and flatter overall, and especially in the area that the slot resonators are targeting, which is around 50 Hz to 250 Hz (see prediction graph on page 6 of this thread).
And finally, the most important: Impulse Response. This shows how the actual energy levels change over time in response to a very short, very sharp, very loud acoustic impulse (eg, balloon bursting, or gunshot).
Frank-REW-IR---Baseline-Empty.png
Frank-REW-IR---1-mil-and-6-mil-plastic-strips--initial-2.png
Frank-REW-IR---PolySlotWalls.png
The improvement here is very dramatic! You can clearly see how ugly it was before this device went in: clear flutter echo, and very uneven "warbling" decay, but now it is smooth and even, all the way down. Obviously and unmistakably, the diffusion is working. Crystal clear. Remember way back on page 2 of this thread, I mentioned that I'm aiming for a decay time of around 220 ms? Judge for yourself from the above graph how we are doing on that...
So there's the current situation! A lot of hard work by Frank, and it is clearly paying off: the room is very definitely heading exactly where we want it to be.
Next up: Soffits.
I have extensively modified the original soffit design, for three reasons: Frank switched to different speakers that are larger, with different dimensions, and have very different characteristics from the original ones we were planning to use; 2) the changes to the rear wall, mostly the curved poly-slat walls; and 3) the desk is going to be very different from the original "placeholder" design. So Frank will be doing some changes to the soffit framing to accommodate these changes, then installing the deep bass traps below and above the speaker, then installing the speakers themselves properly with my proprietary floating system (we won't be posting all the sexy details of how that works... sorry!). After that, we'll do the small sections of slat wall above the sliding glass doors, and finally the cloud. Then we'll do the digital tuning to take are of the few remaining issues that can be adjusted like that, and that's it! End of story!
- Stuart -
(Don't want you getting bored, with nothing to build! 
