Studio Ceiling Height

O

ob

New member
How important is ceiling height?

I am converting a second story garage apartment into a studio. The floor footprint is roughly 17 x 14, which is nice sized, but the ceiling in only 7' high. The roof is very highly pitched, and I think the ceiling joists are also rafter ties to keep the roof from spreading. Notwithstanding that, I am contemplating cutting out the ceiling joists and moving them up several feet to gain some headroom, both sonically and literally. I do this with little carpentry expereince and visions of a cartoon-like explosion of roof tiles when I remove the joists.

Is this really necessary? Does Ceiling height count?
 
Ceiling height does make a difference, especially in a small room. Also, your present ceiling is exactly half of one of the other dimensions, which makes for several resonant frequencies supported by two different dimensions of your room. I just ran an acoustic spreadsheet of your room, and although the Bonello distributions look ok, it would have resonance problems at approximately 80, 160, 240, and 320 hZ that would need quite a bit of treatment to tame. It would be much easier in the long run to raise the ceiling. At least 7.5 feet, preferably 9 feet, would smooth out the response of the room. Either would work, but 9 feet gives you about 400 more cubic feet of volume, which would improve the sound of the room.

You mentioned tiles on the roof. If you're talking spanish tile, as in heavy, then you would want professional help in deciding what to do. There is a good chance that you could do just one of the trusses at a time, so you don't weaken the structure too much.

People have built studios in low ceilinged rooms and managed to make it work; it partially depends on how serious you intend to get. If you want to like your room afterward for a long time, I would give serious consideration to raising the ceiling if it's at all possible... Steve
 
Thanks for your knowledgable response. Actually, the roof is slate, not tile, which explains the steep pitch. I think I will talk to a contractor before I get out my sawz-all.

Thanks again.
 
Everything Knightfly is good stuff.

Depending on your structure, you might be able to double up the beams, and remove 3/4 of them. Or move them all higher, for example, at a narrower part of the peak (say, 1/3 of the way up, giving you an extra foot or two.

We did that in a friend's barn so he had a nice place to build a home based auto repair shop - all of the beams moved up 1/2 the way to the peak, and were doubled. Gave him an extra 6' of headroom to clear the car lifts.


ob said:
How important is ceiling height?

I am converting a second story garage apartment into a studio. The floor footprint is roughly 17 x 14, which is nice sized, but the ceiling in only 7' high. The roof is very highly pitched, and I think the ceiling joists are also rafter ties to keep the roof from spreading. Notwithstanding that, I am contemplating cutting out the ceiling joists and moving them up several feet to gain some headroom, both sonically and literally. I do this with little carpentry expereince and visions of a cartoon-like explosion of roof tiles when I remove the joists.

Is this really necessary? Does Ceiling height count?
Click to expand...
 
Funny you should ask that question - I'll post a couple of links, one to a spreadsheet I wrote about 10 years ago, which is very simple and calculates just axial modes of a rectangular room - the other is one I found (thankfully) BEFORE I started writing a serious one. The simple one (roomtune) is quick, and useful for finding where to move one wall when you have two other fixed dimensions, and the complex one calculates ALL three modes for all three dimensions of a rectangular room, and displays Bonello distributions/mode strengths as well as an ascending chart of all modal frequencies. The complex one requires entering dimensions in inches, and you have to follow the first 3 directions or you don't see updated results - but it works great. Saved me several weeks since I don't do much spreadsheet work...

Here is the link for roomtune -

http://www.prorec.com/prorec/downloads.nsf/filename/140AB4809CEFB83586256B570031B581

there are basic directions included with the self-extracting file, in Wordpad format.

and here is the link for modesV2.xls -

http://www.studiotips.com/

(click on "calculation tools", then download - MODESv2p.xls )

I use the simple one I wrote for roughing in possible combinations of rooms in a given space, then check fine tuning with MODESv2p -

Both of these require a spreadsheet program to use. They both will work with Excel, and mine also includes a Lotus version.

Post back after downloading if you have any more questions (you probably will, I don't remember getting too verbose on docs for a change) Hope this helps... Steve
 
Knitefly - for some reason, the roomtune selfextracting file won;t run on my machine. Anyone else with XP have this trouble? Could you post the excel spreadsheet?

Thanks
Kevin.
 
knightfly,
Do you have a spreadsheet, etc that will take into account a cathedral ceiling rather than a flat ceiling? In my case the live room will be approximately 26' x 23' with 10' walls and a peak in the middle of about 13 to 15 feet. I can have the roof pitch adjusted before building to set the height I want. Recommendations on this height with the above dimensions?

DD
 
Here is a zip of roomtune.xls - this board doesn't mention .xls as a file you can upload.

Since there are no docs with the zip file, here's the basics - the only cells intended for data input are under the heavy type L, W, and H, at the upper left corner. All other fields are calculated.

Enter your length, width and height in feet and tenths of feet. You can start at the left, enter values and use the arrow key to both leave the field and enter your value - for the last dimension, use the ENTER key instead. Then, if you want to play "what if" with just one dimension, place the cursor over that field and just keep typing numbers followed by ENTER - the sheet autocalculates each time and you can pick the dimension that gives the most even spread of frequencies on the bar graph.

The goal is no two modes closer than 5-6 hZ, and no spread greater than 15-20 hZ - not as easy as it sounds.

The dim's that the sheet opens with are one of Everest's "ideal room" ratios. Note that there are cases where "ideal" doesn't meet the mode spacing (W2-L3 for example)

Save the original somewhere safe just in case you enter something into the wrong cell...
 

Attachments

  • roomtune.zip
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D-Don, unfortunately I've yet to see one and won't probably live long enough to find time to write one. The best I can offer is to use the average of ceiling height and give very little worry to any "problems" that involve that dimension.

The good news is that a vaulted ceiling works great in a mix room to minimize reflections at the mix position. Best placement would be ceiling ridge line parallel to a line running through both speakers, with the speakers (if not soffit mounted) about 3 feet from the rear wall. It would be better if the median plane (the plane running equidistant between speakers and through the center of your head) is the long way of the room and centered.

An Ideal mix zone would have the walls also splayed narrow at front, with polycylindrical or other absorbers at the rear. Bookshelves with several books in them and nothing that rattles work OK for this. This would give a Reflection Free Zone at the mix position, with (in the case of your 26 foot room) enough delay between original sounds and diffused echoes to achieve tight imaging.

The Studiotips site has several other helpful calculators for absorption, reverb, etc - One of the guys works for Auralex, but he doesn't seem to abuse it much if at all... Steve
 
No prob - now you can be like me and sit around dinking with spreadsheets instead of actually BUILDING stuff... :=)
 
Hey Knightfly,
I tried the Room Tune. Only the macro's won't work (Ctrl-Shift-C, etc). The tables update as I enter the measurements but the charts don't update. Said something about having to change something with the host application. I not extremely familiar with excel. Any suggestions?

Thanks
DD
 
Hey DD, I think you may be confusing the two spreadsheets. roomtune, the one I wrote last decade, has no macros. I am nearly illiterate with spreadsheets myself, which is why I was ecstatic to find MODESv2 on the Studiotips site. THAT sheet DOES have macros, and after entering dimensions you have to do CTRL/SHIFT S, then CTRL/SHIFT C. That updates all the charts.

If you're having problems with roomtune's charts updating, you may need to change the setup in your version of Excel. I'm not a lot of help there - I looked up in the excel help index for "chart", "protect", etc, and found nothing that should do that.

If you know anybody locally that works with Excel on a regular basis, maybe they can find out what's different on your version. It's probably something really simple, just not to a rank amateur like me... Steve
 
MODESv2 does require you to ENABLE macros - ON my machine, once you do that, you enter your dim's in inches, hit CTRL-SHIFT S, then CTRL-SHIFT C, and it recalcs the charts. If you don't do those things, you're right - the tables update, but not the rest.

If your machine is at work, make sure your IT department doesn't have macro's disabled in your copy because of viruses. Hope that's the problem, 'cause I'm outa ideas quick on this subject... Steve
 
Knightfly,
That might be it. I work at a government facility and they've really tightened down in the last several months. We're still using NT and I downloaded it at work. There's probably some way they disabled it. I know it won't let us download anything executable or .mp3, etc. At least they haven't blocked hr.com yet :D :D I'll download it from here at home and try it again.

DD
 
Cool - Is that a spiffy what-if toy, or what??!?

I've been planning various possible scenarios for a studio complex off and on for the last 10-12 years while living with a bedroom or the room I built in one side of a 36 x 48 barn, and the way I tend to use the two sheets is this: Take the available total space you have available, rough out a plan with a cad program that includes whatever rooms you want (tracking, control, drum, vocal, ?) then, start with whichever room you consider most important acoustically; if you're into acoustic instruments and like natural sound, then probably the tracking room would take first priority for being acoustically as perfect as possible, followed by the control room. If you're more into synths and such, then probably a large control room with room for a couple stacks of keyboards. Don't forget a separate room for instrument storage, sympathetic vibrations with guitars and such can ruin things for a recording. Pianos are their own reverb chamber and should be out of the room unless being recorded, etc. -

Anyway, whichever room gets the first priority, I use the roomtune sheet to rough in dimensions for best use of space combined with a smooth graph. Not necessarily in order, but with no bars closer than 5 hZ and no gaps greater than about 20 hZ. Once I find a combination of dimensions that work (roomtune is quicker for me here) then I plug those dimensions into MODESV2, and verify no problems with modal density (Bonello chart) or mode strength (modes chart)

It helps to know the exact wall thickness you want, adding up stud width + all the various layers, RC, etc - This makes it easier to quickly draw different floor plans without all the details of the wall, only the correct outer line distances.

Also, remember that in the case of a smaller isobooth, you can use a taller ceiling to maintain good dimension ratios. A room 10 x 16 x 22 could concievably have a 22 foot ceiling if you needed less floor space taken - the modal response would be the same, only the acoustics would be different because there was less distance in the floor plan to tame reflections. Still something to think about for isobooths.

Blathering on again, gotta stop - I'm glad you got away from the evil secret keepers so you could get the sheet to work... Steve
 
Whoa! Did you check out the Sabin/R60 Room Calculator at http:\\www.studiotips.com ? It's the one that says "The latest version of Scott's excel sabin and mode speadsheet - The Sabin Mode sheet is for calculating RTC 60, Sabins and Modes." I bet he took some aspirin after building this spreadsheet. I'll be using this one too when I start to put the walls up.

DD
 
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