improving recording room acoustics

check out my studio plan: http://www.lowswing.de/05plan/plan.html the studio is working very well and very successful, this is about time to invest money on the recording room acoustic to make the studio even better. let me discribe it:the west wall is plaster wall the east one is covered brick wall they are parallel, the ceiling is cs. 3.4m high and paralel to the wooden floor. i guess what i really want is a wall units to fit on the parallel walls, hopfully from wood to give the room more "woody" character. does anyone have a plan or idea what can i do/build? what to do with the celing (it is build from gypsum boards there for cant hold very heavy things attached to it)? i'm getting flutter echo on some points in the room . thanx guy ps the r60 calculator suggested i have o.7sc reverb in the room, i think it is double as long, would be nice to cut it down a little.

Greetings! You gave us the ceiling height- what are the length and width dimensions? You also mentioned that the ceiling is drywall- no, the drywall can't hold much, but the ceiling joists above should be able to hold something. If you didn't build the room, and don't know what the structure is, you should open the ceiling up and find out before you attach anything too heavy to it. Killing off flutter echoes from the ceiling would be pretty easy, tho. With that much ceiling height (3.4m = around 10', right?) you have plenty of space for a cloud. 4" of rigid fiberboard, hung with a 4" gap between it and the ceiling, should clean that up nicely. Most of the advice on this board for tracking rooms is to build the floor reflective, and the ceiling absorptive. By the way, what's the floor made of? As far as the walls go, there's lots of stuff you can buy and lots of stuff you can build. Does your room have any significant low frequency problems you need to correct? If not, chances are you can put diffusors up over most of the walls. Go to www.rpg.com and have a look at some of the stuff they build. If you do have low-freq troubles, John has plenty of advice on how to tame them. If your room is big enough, I'd think you'd be happier going with mostly diffusion. Kase www.minemusic.net

I think Kase meant www.rpginc.com

Have you actually measured the RT60? Calculations don't always (if ever) get it right. One method of getting a better idea (cheaper than un-necessary construction) is room analysis software. One of the less expensive versions is here - http://www.etfacoustic.com/ Runs about $150 for the basic program, tops out at around $550 for all plugins, including test CD, mic, preamp... As for killing flutter between walls, here's one option - http://www.johnlsayers.com/HR/index1.htm Check the Side Wall Absorber plan. I wouldn't recommend using less than about 4 feet between "teeth" of the sawtooth front shape, as longer wavelengths tend to "average" the distance so aren't affected as much. Sorry, I just noticed your other measurements were metric - the plan shows that too, change that minimum above to around 1.2m... At what frequency did your RT60 calculator show .7 seconds? If your room treatments aren't uniform, you could be hearing one frequency range ringing out longer. For the flutter between ceiling and floor, we usually recommend hanging an absorbent "cloud" of at least 2" rigid fiberglas or rockwool, spaced off the ceilng at least a few cm (like 5-20), and slanted where there's adequate headroom. For a larger tracking room, the "sawtooth" spacing similar to those wall units could also be used, or parallel hangings at different heights per panel. I don't know what's behind your gypboard on the ceiling, or what your sound isolation needs are, but such panels would typically weigh under one kG for a 60cm by 120cm section, plus the weight of a light wooden frame, so probably about 2-3 kG each. Any penetration of the ceiling will affect isolation, how much would depend on the construction and filling between frame members as well as type of fasteners. Hope that was helpful... Steve

knightfly wrote:

... I wouldn't recommend using less than about 4 feet between "teeth" of the sawtooth front shape, as longer wavelengths tend to "average" the distance so aren't affected as much. ...

Hey Steve, looking at those plans for the sidewall absorber, they are made so is would "sawtooth" at about 2 feet. are you suggesting to leave a space in between the units? Maybe I'm just misinterpreting. :? Thanks, Ron

Hey Ron - no space, just change the dimensions so that a double unit (as shown) would be 8 feet wide (and however tall you have room for) - you might need to deepen the unit to increase the angle, if you're trying to incorporate a RFZ - right now, it shows a 6" depth change. That's a 14 degree angle, which is plenty for RFZ in most cases. Doubling the width of the unit (and each "tooth") without changing the depth) would change that angle to 7 degrees, which is enough to kill flutter - but NOT enough to create a RFZ when placed beside the mix position - for that, you'd need to deepen the units as well, so that the difference in depth from shallow to deep was more like 14-15 inches per 48" "tooth" - Hope that helped... Steve

Got it. :)

thanx for the advice :D I'm planing to place fiberglass inside of many wood boxes with diffrent depth on the celling i recon the it will make a strange pettern that might look good abser and diffuse anf light to hang. another question: a while a go i saw jon sayers design for variable wall units as he built for the piano room in left-bank. i can't find the link anymore. i want to build this on the walls. please send the link or the design if you have it thanx guy

Guy, I was looking for your floor plan and came across this forgotten post with no answer - is this the link you're looking for? http://www.saecollege.de/reference_mate ... encies.htm Or possibly this, near the bottom of the page - http://www.johnlsayers.com/Studio/Pages/update_3.htm Sorry your post got lost for so long, hopefully the info is still useful to you... Steve

thanks for all the replies ,steve! better later than never :D