The Very Large Recording Room Challenge.

Hi. Im Arnar and im from Reykjavik Iceland. First time poster , long time lurker. I have the task of fixing up the acoustics of this recording room. There is not a huge budget but enough to tackle most problems and build the structures needed. Effectiveness is more important then looks and dyi solutions are welcome. Sorry for linking to pictures but I couldnt find out how to upload. Pictures will stay online though. Room Dimensions : Length 53.1ft/16.2m Width 40.6ft/12.4m Height 22.3ft/6.8m Volume 1366 m3 - 790.7 m2 Ratio 1: 1.82 :2.38 Reverb time goal ...1.25 sec ?... The room will need to work for string ensembles , grand piano and stuff like that but still be multipurpose. This room optimally would need to work for most recordings but people would come there for the big room sound. Pictures of the room. Right wall. Right wall 2 Front wall Left wall 2 Left wall 1 Back wall 2 Back wall I did some measurements in the room and here are the results. All these measurements are made in the center of the room, moving back one meter per measurement. I do have more locations/measurements so I could post them as well. 41.5 -42.4 : 50.5-53-55.4 : 70 -80 : 96-100 Show up as modes on the measurements. Slice interval 50 ms Window 300ms The measurements seem to correlate nicely with the calculated room modes. And a proposed reverb time plot. I still havent made a full range measurement but i could if needed? Questions. 1. I have done acoustics for smaller studios and control rooms but never such a big room and Im wondering what are the main considerations ? 2 .Do I need to be as concerned about the modes in a large room like this like I would in a smaller room ? 3. What would be considered critical in a room like this ? What would be the priority (apart from getting rid of the flutter) Flutter echos are a definite problem in this space and they go pretty low in frequency, upper midrange even. The room is pretty much untreated but has been used for recording already with ok results. The entire ceiling is covered in Rockwool with an airgap behind of about 30 to 40 cm. The walls are perforated Masonite with a thin layer of rockwool behind except for the back wall which has a wooden surface. The room feels kind of dead and claustrophobic when you have spent some time in there and musicians have commented that there is little support from the room. I feel like the room could be more lively somehow but I might be wrong? Primary goal is to stop the flutter echos but id like to tackle some other problems as well since im building structures anyway. Id like to stop the flutter echos while also slightly livening up the room. Using these structures to tweak the reverb time and modes would be nice as well. This space is used to record tv ads as well so there are two walls that cannot be touched , two walls with an "eternity slope". This is the complete front wall and about a third of the right wall where it joins the front wall. This can be seen on the pictures, luckily the opposite walls can be treated. All other surfaces are fair game. Isolation is not a big concern . The control room is situated through the big grey door on the left wall . Cameras are used to see what is going on in the room. A second control room might be installed on the back wall besides the staircase and Iwould install a window there but that will not happen this time around. I will provide more information , im working on getting the floorplan drawing scanned but thought id get this post started. Thanks for any advice. (Im editing this post now) Arnar

Hello and welcome arnarinn, Before the experts will chime in here, you want to fill in your location, and probably re size those pics. - viewtopic.php?f=17&t=7572

ghetto solutions are welcome

I'm not trying to be a jerk here, but are you referring to solutions to the confinement of segregated economically challenged peoples or are you looking for a cheap affordable means of putting this place together perhaps. In any case, I think "ghetto" might be the wrong word, but I know what you meant :) I would just find a word a bit more definitive and less subjective. - Ian

Oops....I´ll have another look at the rules. Im from Iceland , didnt know that ghetto was offensive. I´ll just redo the post.

No worries my friend, I am not extremely offended by "ghetto" but, I'm just trying to save you the hassle from others who might. No need to redo your post either, just fix those pics. My mother happens to be Jewish, (my father mixed Muskogee Indian & Caucasian) so we understood ghetto derived from the Venetian locale of the Jews which separated them from rest of the Venetians. True, the term pertains to a poor area, it's just not very justified as an adjective. But before this turns into a grammar/history/heritage lesson :blah: , don't worry about it, it's no big deal :D . So just have a look at the guidelines, and I'm sure people will help you in no time, it's seems like you have a pretty good presentation so far, so it should be rather easy since we know where your location is now. All the best of luck - Ian

Clouds clouds clouds! Depending on the current lights that are in the roof for the Ads, can you space out 12-20 clouds in the ceiling? Also on the 2 walls you can touch, why not try "echo stop" or similar plasterboard. Alot of companies make it. it's 12.5 thick but full of spaced holes. http://www.boral.com.au/Brochures/order ... asterboard Build a second wall say..1/4 of a metre from the current 2 walls, fill with R13. In an area that big you wouldn't want to make it too "dead"

Im working on a sketchup drawing as well as tossing around a few ideas.... Clouds will probably be needed to reinforce the players area. What im working on at the moment is some kind of Bulkhead structure or wedges for the two walls. Im wondering about the schroeder frequency , in this room its about 59 hz. So I guess its mostly about diffusion ?

Im wondering about the schroeder frequency , in this room its about 59 hz.

For those dimensions, the Schroeder frequency is 39 Hz. Why are you concerned abut it?

So I guess its mostly about diffusion ?

From 39 to 156hz, yes. Beyond that, its all specular, for your dimensions. - Stuart -