CR Treatment and Tuning---The home stretch!!

Hey Greg, I haven't built the doors, so no variable yet. I'll put a post together tomorrow morning detailing these things better so you all can have an idea of what's going on. I didn't tune them. "he who shall not be named did" :P Results may vary for anybody who attempts these. "You know who" struggled for weeks playing with his calcs to figure out how to pull off the multi function features. (Combination helmholtz/membrane) Since there is no testing feedback, its hard to know if they even work. The room sounds great, so I'm not going to sweat the accuracy of any of the rest of this treatment. I'll do some testing in the end. I will say that the units have tamed the low end effectively. The room is not as boomy as it once was.....Sooo, good things I guess???

Hey all, Got some wind in my sails and good weather, so I'm working frantically...I'll put a more comprehensive post together soon, but I want to push hard while running on all cylinders. Also, I keep forgetting to take all of the photos I need to when the internals are still visible cause I'm in a work frenzy...Got a few more pics to take, which I'll get this time around.

Gorgeous work as usual! Greg

Plus one Frank! Can't wait to see how your variable acoustic treatment works in the real world. The whole installation is tremendous.

Thank god for the CNC!

Ok all, its been awhile but I certainly stayed busy. Fortunately I can stay functional even with the virus keeping me at home....So I'll be doing a series of posts to give as much detail as I can. Stay tuned! :snack: Here's a pic of the wall units without the doors...Finally on the wall and finished without the doors. I'll be recording and getting a feel for the room before I go to the last step of building the doors and adding reflection back to the room via a ratio of boards over the existing absorption. The room is still quite dead...(I like it that way for just jamming and composing) Its less fatiguing on the ears and I get more clarity, which makes me happier...

First of all a couple of model pics to illustrate the door function....Fortunately the room sounds awesome to me without the doors being done yet. I'll need to finish the process to get the reflection options back in the mix though.

Awesome - that room looks like a million bucks!

:D Thanks man!

The internals consisted of multiple features. Limp membrane traps, some combined with helmholtz resonators. Also some absorption and of course lots of diffusion. This helped calm down some flutter echo and made the room generally sound smoother with more clarity.

The most complex parts are the combination Helmoltz/limp membrane features...

The center module is just a curvy diffuser filled with insulation.

Here is some data comparing the room with old treatment to where it is today. The decay time has improved marginally, which is to be expected since I haven't added the reflection back into the room yet. There is improvement in the flutter echo issue and overall room sound..I am stoked about that! It sounds great in here. Getting lots of compliments from visitors. :mrgreen: The low end has been tamed quite a bit! I left the rack toms in the room in the new tests, so there is a bit of ringing in the waterfall. No big deal. Another issue with these comparisons is the difference in convertors. The old was done on an RME UFX and the new is done on an Apollo x8p. I'm only posting one mic position because the data is largely similar and that would be a ton of graphs! I will post more data in a month or two, once I get the doors built and installed along with the reflection boards... Mic placement pic: Old treatment position 1: New Treatment position 1: Waterfall: Old treatment position 1: New Treatment position 1: RT60 graph: no significant change here.... Old treatment position 1: New treatment position 1:

Hey thanks so much for posting, all this info is invaluable. Your thread is absolutely gigantic and full of gold! Your treatment looks great and I'm glad it is improving your rooms overall. The curvy diffuser looks very interesting... so did you wrap a thin layer of ply over the curvy skeleton? Is it completely sealed airtight and filled with insulation or is it left open on the top and bottom of the curve? Thanks! Paul

Hey Paul, it is indeed a bendable plywood product, 3/8" thick... the side modules are sealed because they're tuned. The center part is not....Just filled with insulation. I don't believe it's critical which type you use. I found that getting the plywood wet makes it more bendable if it's brittle. Mine was starting to get that way after sitting around for so long. Thanks for the kind words. I'm very happy to be in the place I'm in finally!

Frank, your work ethic and skills are so inspiring. Wow! Greg

Thanks man!

Been while since I've caught up on this. Amazing stuff in the updates I've missed.

Thanks. Gonna start on the doors for the varifusers soon when the smoke from the fires clear up around here. Been really getting some good use out of the room. Honestly, I like it dead. May not push to liven it up too much.

Gonna start on the doors . . . when the smoke from the fires clear up around here.

Yikes! Hope that's not too close for comfort Frank!

Been really getting some good use out of the room.

That's great to hear - I'm looking forward to seeing & hearing more soon. Best wishes, John.

Fortunately the fire didn't get to me, though 929 residences were destroyed in the area. Its getting bad here on the west coast. Only going to get worse sadly. Thanks for following along! looking forward to re-purposing my garage as a proper clean and tidy workshop. Been holding off on that till I finish this stuff.

Finally getting around to finishing the doors on the wall units. The last serious project. The rest is just adding reflection back to taste if I decide to.

Stadank0 wrote:

Finally getting around to finishing the doors on the wall units. The last serious project. The rest is just adding reflection back to taste if I decide to.

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Absolutely incredible workmanship, very impressive! Can't wait to see the final REW measurements when it's all complete Paul

Thanks! Probably won't be any measurements soon after cause I'm going to be slowly adding reflection back. I don't expect the doors to change the equation much up front. I'm suspicious that despite their complex design, they won't offer a wide range of damp to live. Time will tell. Stuart would have liked me to build and install 6 of these behemoths! I didn't want to go there because of the headaches that would have been created for me logistically. I'm really happy with the room being on the dead side for personal use. It lowers the overall loudness a bit and gives the source more clarity. I'll certainly dabble with livening up the room eventually. Its just not a priority in the short run. Mostly, I just want the complex stuff off my plate for good. Adding boards to the walls later is cake after all of this...

Soundman2020 wrote:

...which is based on the famous B&K curve from several decades back, with some modifications suggested by Floyd Toole in some of his papers and books...

Which one are you reffering to, the "trained listeners" one?