drum overhead diffusers (slot resonator?)

[Disjointed]

so i currently have a cloud over the drumkit (which is up on a platform) ... it did a good job at deadening the flutter i was having, but i am beginning to think i would be better off with a diffuser up there .... sweetening the highs instead of killing them.

i think a 2d or 3d qrd would be too heavy up there (i actually built one to 2'x4' - and it could easily crush someone)

so ive been thinking about something like a slot resonator, possibly curved (deeper in the corner and flattening out towards the front (ie. like a quadratic response curve)

anyway, I was wondering if anyone had links to design calculators or even just designs that could help me out

thanks

[Disjointed]

do you think this is maybe a bad idea, stick with the cloud?

its a 10.5' tall room, so 10' off of the drum riser, i think thats enough for the diffuser to work.

does it seem like im heading in the right direction here?

any other ideas?

thanks
-mike

[Disjointed]

so 100 views and no one wants to help me design or, or critique the reasons for my drum overhead resonator?

??

[Glenn Kuras]

What is the over all size of the room? How close are the side walls to the drum set? Absorption above a drum kit, IMO is just safe, using diffusion, IMO takes a bit more thought.

[tenchijin2]

10 ft means about 6 ft from the cymbals and about 3 ft (give or take) from the overhead mics. I say that's too close for diffusion to be effective.

What aren't you liking about the cloud?

Do you have some treatment on the sides? What are the other dimensions of the room?

[Glenn Kuras]

10 ft means about 6 ft from the cymbals and about 3 ft (give or take) from the overhead mics. I say that's too close for diffusion to be effective.

Good point.

[Disjointed]

i see your point about the cymbals and the height,

i currently have the 4 x 6' cloud above the kit
its on a deadened (insulation filled) and isolated riser.

the kit is kinda in the corner, which has a 45* angled bass trap 2' wide, with 2' on each side of that broadband trapped, with another 50% of the next 2 feet broadband trapped (picture below)

maybe too much broadband?

i mean it sounds pretty good, but i think it could have more high end 'shimmer' ?

the room itself is 18 x 24 .. i use it as a one room setup (2 iso booths, drums and mixer in the large section)

thanks for the replies, i appreciate it

[jwl]

I'd keep it as is. If you add diffusion, add it further out in the room. This way you can get some tighter, dryer sounds up close, and some killer room sounds further out in the room.

If you definitely want to build a slot resonator, then there is a calculator here:
John Sayers' Recording Studio Design Forum • View topic - Corrected Helmholz Spreadsheet

Be careful, a lot of the calculators out there are incorrect, due to the formula behind these calculators being published in a book with a typo that no one noticed for years!

[Glenn Kuras]

JWL gave you the right answer, but also you could add some diffusion on the bare areas around those panels you have now. It can't hurt.

[Disjointed]

thanks for the replies...

i like both the ideas of adding some diffusion to the long throws and some lil 'why the hell nots' near the kit..

im a dayjob carpenter, so i have a tone of scrap wood lying around - time to make use of it.

I had been trying to keep the room symmetrical for mixing purposes, but have since realized that i cant have the best of both worlds in one room... so to hell with symmetry! (ill prob add on a mix room anyway, or build a new studio, why not)

thx again

[Syncamorea]

I have built a few diffusors for control rooms and studios with mixed results. Years ago, I tried using a variety of models I found in the literature and never seemed to get the expected result. Maybe my equations had the typo and I was just calculating error functions. O: The last ones I built were a pair of corner bass trap / diffusors that had internal volumes of ~200 cubic feet each. The diffusion surfaces were about 60 square feet on each trap. They were framed in 2x4s and faced with oak slats that ranged from ~1/4" thick to ~3/8" thick and ~1.5" to 2.5" wide. I used thin strips of Dynamat (~1/8" thick) between the oak and the 2x4s, and attached the slats with drywall screws. I made the traps with a door opening so I gould get inside and swap or move the dampening material and spent a couple of years trying stuff from mineral wool to down sleeping bags. My favorite was 4" mineral wool right behind the slats with the main void nearly full of down bags hung inside lightweight cotton sacks.

The room these were built into had a height ranging from ~9' to 10.5', a width of 15.5' and a length of 23.5'. Typical bass traps had failed because they made the room too dry. Putting in the diffusor/traps worked great because they tamed a bad resonance that was ~45Hz and more importantly, largely fixed the room's main problem, which was a very annoying series of slap echoes in the ~1000Hz range.

On a whim, I took the leftover materials and made a couple of ~6' diameter diffusors and hung them from the ceiling above the main monitors (which were in the 10'5' tall part of the room). I used a band saw to freehand cut some 2x6 material into base pieces that were full width in the middle and tapered down to ~1" thick at the ends. Four of these were joined to look like: # , except the angles were square. Then the leftover oak slats were added to make the final shape hexagonal. I stapled grill cloth to the back side, then filled the void with mineral wool. They worked like a charm when hung from the ceiling with a couple of inches of air above them. I mention all this because we also used that room to track a drum set and considering that I'd rather have a larger space, once fitted with these and a few other treatments, this room was very good for drums and recordings made in it sounded focused, punchy and the reverb sounded natural and large. Cymbals that worked great in clubs, like Paragons, didn't overwhelm the room like they can do in some smaller places, and they recorded really well with great overtones and decay. So maybe the room was a little dry but it was subtle and musical. Electric guitar also sounded great in the room with the amp along the long wall. The owner liked it so much he used that control room as a studio with small groups that didn't overcrowd it.

Sorry to ramble, blame the caffeine, lack of sleep, or both.