Any advice on my studio ceiling contruction?

Hi, I am new to this forum but hope to get some good advice on the below topic. I have a recording studio and want to improve the acoustic properties of my live room. Before starting the construction I would like to see if any of you have suggestions or other ideas! The problem with the current situation is that I have some flutter echoes, I think they are between floor and ceiling but they can also be between the suport beams on the ceiling (see photo's). The objective for the room is to be quiet lively, suitable for recording drums etc. If needed I can alway deaden the room locally with gobo's etc. I therefore want the ceiling to be a combination of absorption and diffusion. General info on the studio: The walls are stone. the floor and ceiling are unfinished wood. I have some broadband absorbers on the walls. The general dimensions (all metric) are LxWxH 10 x 7,2 x 3,5. The ceiling has two angled sections (no acousting problems in that area) and a horizontal area (support beams and the same wood as on the floor). The current plan: My plan is to fill the cavity between the support bars with rockwool slabs (9 cm thick) and cover this with fabric. In order not to deadend the room too much I am planning to cover the ceiling with wooden slats of 12 mm thick and random variating width (44, 69, 94, 119 mm). Between these slats I am planning to leave a gap. I also want to angle the slats slightly in order not to create new flutter echoes! (see sketch) Please refer to the photo's and sketches for clarification. My questions are: 1) What do you think of the design in general? 2) Do you have suggestions for the size of the air gap between the wooden slats (and total percentage gap versus wood)? 3) Any ideas for other (lower cost) solutions? PS: I am planning to build more diffusors for the walls. It has become a long post but I hope with a little more information You are more able to give good suggestions! Many thanks in advance!

You may get a quicker response if you follow the rules and enter you location [url] http://www.johnlsayers.com/phpBB2/viewtopic.php?t=7572[/url] All the Best Alan

oeps, thanks for the tip!

Kijk dat is al beter! (@ the rest: freely translates into "you're getting there already" in Dutch)

if i'm reading your plan right, you're adding a layer of rigid insulation, a frame with cloth, then slats on an angle. if you're isolation is ok, then i think the ceiling slat idea will be a nice one. alternatively, you could also build a number of 100mm porous absorbers (1200mmm x 600mm) and create a checkerboard pattern across the ceiling (leaving 30cm on the corner-to-corner space) just below the joists. between the space from the hard boundary above and the edges exposed you should have a nicely balanced space also. you could even mix and match and have some slats in some sections and some porous absorption in others...

Hi Glenn, thanks for your input! Your understanding of my plan is correct. I do not need further sound insulation. I plan to put the rigid absorption material between the joists. To avoid the fibers coming through the ceiling I want to cover it with cloth (just tacker it onto the joists). The slats are for sound reflection and diffusion and the gap betwen the slats is for absorption. I have thought about your idea as well, hanging absorbers underneath the ceiling like a checker board. I am a bit worried that I will still get reflections (flutters) between the joists and that it will become too much absorption? I quiet like the way the room sounds now (apart from the vertical reflections) and don't want to make the room too dead. The advantage of your proposal is off course that is probably a bit cheaper to make and more flexible to change (ie hang more or less absorbers). Do you have an idea for a bit more reflexion too? And would it be an idea to hang these absorbers between the joists? The joists are 20 cm, so if I would level the underside of the absorbers with the joists they would still effectively be 20 cm deep absorbers. For my design I am worried that it will turn out to be a tuned absorber! I don't want to tackle specific frequencies. Does any body know if there are any rules to follow with regard to the space between the slats? Any way thanks, it is good to have some input! PS would this thread belong in the "studio construction" forum?

Probably better off in the Acoustics forum, where I've moved it... Steve And you're in good hands with Glenn, I've yet to see anything from him but good advice - thanks, Glenn

thanks Steve! good to see you back!

Thanks Glenn, it'll prob'ly be short/sweet - more seriously paying work looms as we speak :D Steve

Hi Is there anybody who has some further suggestions for my ceiling or comments to my plans? Thanx in advance for share ing your ideas! Michel

It won't be a resonator unless you seal things up inside. I also agree with Glenn, I wouldn't do slats everywhere in the ceiling. There will be places where you don't want any reflections at all, ie, a ceiling cloud above the mix position, and also above any crucial recording areas (ie, above the drum kit).