Studio Design - Teen Drop-in Center

I have been asked to help a Kids/Teens Drop-in Art center design a studio. I went by today to check it out. The space has been determined and is enveloped in a brick and concrete section of the building. . . so the only isolation to worry about is between the rooms within the Studio itself. The ceiling is fairly high (13' 6") for the small space (33' x 11'). They will be recording rock, hip-hop as well as some acoustic. . . and whatever else happens. They are hoping to get 4 rooms: 1) fair sized control room; 2) fair sized drum room; 3) Small vocal booth; 4) Tiny Guitar Amp Booth. The studio will be computer based with a small desk setup with speakers, monitor tiny board etc. . . and they also hope to fit a couch in the control room. We would very much appreciate ideas on the best floor plan and interior wall layout. We are hoping the control room can go in the middle with the Drum booth on one side and the other two booths on the other side. We were also thinking the Vocal and Amp boothd will only have 8' ceilings to leave some storage space above. This will be done on a very tight budget. For acoustic treatment, since it is an Art Centre, I was thinking they could construct a bunch of frames, cover with canvas, paint art, fill the back with fiberglass and install all over the concrete to deaden and diffuse. For cheap iso doors we will take a normal interior door, remove one side, take out all the honeycomb cardboard, glue and screw in an addition frame, glue in 3 layers of Gypsum, and use an exterior door frame with weather stripping. All doors will be double doors. Dividing walls will be double wall construction with 2 layers of 5/8 on one side and 2 layers of 1/2" Gypsum on the others, etc. . . There is another opening up high that I think we can sneak supply and return air through. We will get some baffled duck work and build baffles for the return air between the walls. Your input on floor plan or any other ideas or comments would be great. Thanks in advance.

Maybe check out Garage Studio 1, here - looks not too far from what you asked - http://www.saecollege.de/reference_mate ... /Plans.htm Also, instead of gutting a door, check out this thread - http://www.johnlsayers.com/phpBB2/viewtopic.php?t=1662 The term, "very tight budget", means less than a million to Bill Gates - to a guy pushing a shopping cart with a dog and all his belongings, it's $.25 - what's yours? (Not trying to bust your chops, it's just very difficult to know what to suggest without some idea of scope... Steve

Steve - Budget - Good point, $ are relative. I am guessing we will have $8,000 (Canadian = $5000 USD) total including labor, but I am sure there will be some volunteer help along the way. The people running the facility are working to raise the required money now. The solid brick and concrete walls will really help reduce much of the cost. Garage Studio 1 looks like a good fit. It is using sliding doors, which are expensive and I would imagine the isolation is not that great. I am thinking doors and smaller windows would be better. Any comments? I read thru the posting on acoustic doors. I have made the doors I noted in my original post for my home studio. It took about 1 hr per door to do the modifications and the materials were very inexpensive (Gypsum and Glue). The results proved fantastic, with two of these doors you can't hear a thing in the vocal booth. I was looking thru the Acoustics forum and found a lot of ideas for the highs - mid - high bass, but did not find much info on controlling really low frequencies. I find these smaller rooms have huge problems in the 40-70 Hz range, usually with a null at the mix position. What is the most space concious way to do this? Another question, I love a high ceiling, but is the 13' 6" ceiling a good thing in such a small area?

I was looking thru the Acoustics forum and found a lot of ideas for the highs - mid - high bass, but did not find much info on controlling really low frequencies. I find these smaller rooms have huge problems in the 40-70 Hz range, usually with a null at the mix position. What is the most space concious way to do this?

Helmholtz absorbers, with deeper ports than 1". There is a calculator on the site for them.

Another question, I love a high ceiling, but is the 13' 6" ceiling a good thing in such a small area?

Why would it not be? F. Alton Everest in one of books actually details doing that in control room to gain additional volume. I seem to recall seeing a recently (2-3 years) designed studio by Russ Berger that did the same thing. A thing to consider with cost, have your regulars at the center spread the word that certain items are required. Many buildings when torn down or renovated throw away things that you would otherwise spend a lot of money for. IF you are a registered charity, you can also offer tax deductible receipts. Good luck! Andre

A thing to consider with cost, have your regulars at the center spread the word that certain items are required. Many buildings when torn down or renovated throw away things that you would otherwise spend a lot of money for. IF you are a registered charity, you can also offer tax deductible receipts.

Good idea, I will check into their situation and see if they have contacts that may donate materials new/used.

I thought I read a post from uou asking about smaller bass traps. If you are wrkong with detail, design the walls to have higher absorption at the frequencies concerned. Don't forget, you have a great ceiling space to work wiyh, so space is not a great concern. You (hopefuly) have many people scrounging the area for used material. Include on your list of things wanted insulation. With a bit of luck, you can have the most amazing acoustics for that size facility. I am starting to think about moving to Winnipeg just to use that place once it is built. The mosquitos scare me though.

I thought I read a post from uou asking about smaller bass traps. If you are wrkong with detail, design the walls to have higher absorption at the frequencies concerned. Don't forget, you have a great ceiling space to work wiyh, so space is not a great concern. You (hopefuly) have many people scrounging the area for used material. Include on your list of things wanted insulation. With a bit of luck, you can have the most amazing acoustics for that size facility. I am starting to think about moving to Winnipeg just to use that place once it is built. The mosquitos scare me though.

Two quick things - first, don't use the Helmholtz calculator at the SAE site, it's one of dozens that use the wrong formula that's been spread net-wide - instead, use the corrected one I posted in the Acoustics forum - http://www.johnlsayers.com/phpBB2/viewtopic.php?t=1363 Also, the easiest, cheapest way to keep your masonry walls from killing you on bass is to "furr out" about 4", put light insulation between furring, and put 1/2" gypsum wallboard up - 4" gap with 1/2" gypsum gives a panel frequency of around 65 hZ - using 5/8" gypsum with 4" gap drops it to 55 hZ - if you wanted to use some of each to broaden the trapping frequency, you might be able to place 1/8" shims under 1/2" panels (no shims under 5/8 ones) so the wall is flush, but has two different panel trap frequencies. Thanks to the insane rises in materials, your budget will still be tight (but you already knew that :cry: ) Yes, the sliders are more expensive and less isolative - John likes them for the open feeling mainly (can't argue with that) but on a budget there are cheaper ways that will isolate more, as you're already aware... Steve

Thanks guys!

Also, the easiest, cheapest way to keep your masonry walls from killing you on bass is to "furr out" about 4", put light insulation between furring, and put 1/2" gypsum wallboard up - 4" gap with 1/2" gypsum gives a panel frequency of around 65 hZ - using 5/8" gypsum with 4" gap drops it to 55 hZ -

Just so I am sure I understand. So the furring should be a 4' x 8' box, 4" deep with the gypsum sheet attached on all four edges etc. . .?

if you wanted to use some of each to broaden the trapping frequency, you might be able to place 1/8" shims under 1/2" panels (no shims under 5/8 ones) so the wall is flush, but has two different panel trap frequencies.

I believe I know what you are saying, to restate. . . so 4" furring with the 5/8" sheet and 4 1/8" furring with the 1/2" sheet. Doesn't the deeper chamber drop the fequency considerably (any source for the math on that)? How well do the furring strips have to be sealed to the back wall? Hi-bass, mids: I have seen some resonators that use drilled panels or pegboard with insulation. Anything like this have any value or will that be in a higher frequency range and are slot resonators a much better bet? The reason I am asking is a may be able to get used peg board for free. I was thinking we could have a canvas front on a frame with Graphitte art, a 3/4" air gap, then the pegboard, and behind the pegboard a chamber full of fiberglass (hopefully free) insulation. Thoughts on design and effectiveness? Off on another tangent --> I have not seen a lot on diffusors in this forum, instead mostly dampening. . . Although not for the control room. . . I have often enjoyed extremely live, highly diffused rooms for the instruments. I find it sounds complex and most often very interesting when recording most instruments, although punch ins can be a problem due to the ambience but much easier in these days of non destructive recording. Also, one can use mobile dampening to reduce the room affect when desired. What are the views on extremely lively tracking rooms?

John likes them for the open feeling mainly.

Yes, you really can't overstate the value of visual communication in a recording studio. Maybe we can find some used ones, we'll see.

The mosquitos scare me though.

Often referred to as our provincial bird, one more reason to stay indoors and record![quote I have attached a real quick conceptual layout drawing. . . real short on detail, nothing to brag about! Comments welcome.

Doesn't the deeper chamber drop the fequency considerably (any source for the math on that)?

No. The formula is f=170/(md) where f=resonant frequency m=mass in pounds per square foot d=depth in inches

How well do the furring strips have to be sealed to the back wall?

How well? Sealed. IT is sort of like of pregnancy, you are or you are not. There is no "just a little bit."

Anything like this have any value or will that be in a higher frequency range and are slot resonators a much better bet? The reason I am asking is a may be able to get used peg board

You hit the nail on the head. The usual problem with pegboard is because it so thin, the frequency range is quite high. However, if you can get lots of it at the right price (free) stack it together to make a thicker panel. That is assuming that all the board in a given leaf are from the same machine so that the holes line up together. Good thinking. Thinking of what you can get get and how to use it.

I have not seen a lot on diffusers in this forum, instead mostly dampening. . . Although not for the control room. . . I have often enjoyed extremely live, highly diffused rooms for the instruments.

With the sizes of most of the rooms discussed here, absorption is the first thing required, Also, people who are ware of diffusion, tend not to ask neophyte questions. There is a lot about diffusion here, but it is relatively short posts. Also things like John's wall units provide a lot of diffusion, but someone not familiar with acoustics would not recognize that initially. Nice layout. A couple of thoughts... Flip the layout so that the angled wall on the right becomes a partition to the darkroom. The space is relatively restricted. Consider reducing the size of the third (smallest) iso space. Maybe just an amp closet, or two? If you can get the material at the right price, stack one above the other. Overall, things look good with what you have presented here. I think the biggest factor is to consider what materials you can get and how to use them to best potential.

No. The formula is f=170/(md) where f=resonant frequency m=mass in pounds per square foot d=depth in inches

So Yes and No then. Yes the depth drops the frequency, but no not considerably in this example of going from 4" to 4 1/8". What is the more complete formula, that takes into acount the 4'x8' size of frame supporting the resonating pane (so we can calculate for different size panels if required)?

Flip the layout so that the angled wall on the right becomes a partition to the darkroom.

There is an error in my drawing text. Darkroom is actually to the right so the idea is already incorporated.

The space is relatively restricted. Consider reducing the size of the third (smallest) iso space. Maybe just an amp closet, or two? If you can get the material at the right price, stack one above the other.

Stacking amp booths is an excellent idea. New Question: Adjusting the room ratios toward optimum - It is fairly straightforward with rectangular room. . . What is the neophyte's best approach to picking good ratios with more complex room shapes (such as room shapes in the drawing above)? [/b]

Only have about 5 minutes til I leave for work, I'll add more tonite - Andre must have had a slight "brain fart" ( I get 'em too often myself) the actual formula for panel resonators is 170/ sq.rt.(MD) - found on p.206 of Master Handbook of Acoustics, 4th ed. - and, for reasons I've yet to uncover, no panel size is figured into the formula - yet, on the preceding page Everest mentions drywall on 16" studs having a particular coefficient of absorption at 125 hZ, etc - :? Later... Steve

Thanks Steve. I try to make certain when I post that I no words left out. And then again I get mistakes like: This sentense contains two errors. Andre

New Question: Adjusting the room ratios toward optimum - It is fairly straightforward with rectangular room. . . What is the neophyte's best approach to picking good ratios with more complex room shapes (such as room shapes in the drawing above)?

Short answer, avoid multiples in the ratio. Try to use prime Numbers in the ratio. IT is actually not so much getting good ratios as avoiding bad ones. As an example, 2:3:4 would be bad, but 1:1.4:1.9 is actually considered one of the preferred ratios. The two are very close. If you are mostly close miking, and have relatively dead room, except for vocals, I would not be too concerned about the ratios. Just avoid multiples,

I do not follow. In rooms that are not rectangular there are more than 3 dimensions to consider (more than just H:W:D). My understanding is that a good sounding room will have the modes distributed across the audio spectrum and not clustered too much in any one frequency region. What is the practicle approach to calculate/check rooms that are not rectangular? For example: What is the practical approach to check for room modes with these shapes below? Also, is there point above a certain frequency, that calculated room modes no longer really matter?

Interesting designs!

I do not follow. In rooms that are not rectangular there are more than 3 dimensions to consider (more than just H:W:D).

The general guideline is to use the average of walls, reduced to a rectangular shape. Eg. a room with an agled wall going from 15 feet away from the opposite wall, to 17 feet, would be calculated using 16 feet.

My understanding is that a good sounding room will have the modes distributed across the audio spectrum and not clustered too much in any one frequency region.

100% correct.

What is the practicle approach to calculate/check rooms that are not rectangular?

As I wrote above in this this post using the averages of distances. We are starting to get into a lot more detail than can be effectively written in a post . The BBC research report 1994*06 gives great detail, and develops the theory behind the current recommendations in ITU and EBU standards. It (the BBC report) is available of the net. Start at http://www.bbc.co.uk/rd/pubs/reports/index.html For example: What is the practical approach to check for room modes with these shapes below? The BBC report gives good detail on that.

Also, is there point above a certain frequency, that calculated room modes no longer really matter?

Depending who you listen to, 200 to 300 Hz.

Thanks for the link to the BBC docs. I looked through the index and a number of these BBC documents. There is nothing on the topic of Optimum Room Shape in BBC 1994/6. However it looks like there is some relevant reading in 1993/8. I will review. By the way, call me stubborn, but practical experience tells me the equation for the centre frequency of a panel bass resonator/absorbor/trap must have the frame size as part of the equation. I see a number of different equations for this all over the forum, but none take this into account. Makes no sense to me.

The equations are the same, just expressed differently - a number raised ? to the 0.5 power is the same as the square root of that number - so the formula 170/sqrt(MD) is the same as the formula 170/((MD)^.5) - The depth and mass of the panel determine the frequency of resonance - the type of insulation inside (and somewhat the location of that insulation relative to the panel) determine the sharpness of the response of the panel (insulation broadens the frequency range somewhat) and the overall size of the trap determines the AMOUNT of absorption at the trap's resonance. I agree that it seems like size should also change frequency, but this formula is right out of F. Alton Everest's Master Handbook of Acoustics, 4th edition, page 286 - I've yet to see it challenged by any of the professional acousticians who post in these forums... Steve

Thanks for the link to the BBC docs. I looked through the index and a number of these BBC documents. There is nothing on the topic of Optimum Room Shape in BBC 1994/6. However it looks like there is some relevant reading in 1993/8. I will review.

You are welcome. Yes I referenced the wrong document for our discussion and you found the right one. I hope you all of the documents at the BBC website of value. It is one of the few sources available for us that is devoted to studios. Andre

Knightfly I thought I saw one deviant of the equation somewhere within these forums without the sqrt or the ^.5, maybe my mistake. Although I doubt I would win a debate with F. Alton Everest, I still maintain it is too simple an equation and must be based on additional assumptions, such as the properties of the materials, not displayed in the variables. Unfortunately I don't have the books in my hands or the booksmartness, just intuition and other experiences. As I see it a dampened panel resonates from sound waves and dissipates the mechanical energy into heat. The further away from its resonant frequency, the less it resonates, therefore more reflected, less absorbed. You can tap an edge supported panel to find its resonant frequency. The stiffer (less compliant) the material, the higher the frequency. The larger the panel, the lower the frequency. The higher the mass of the panel, the lower the frequency. The less space behind, the higher the frequency (same affect as stiffer). So why are M and D the only parameters in the equation?

The other formula you saw was an error, since corrected - and I agree with you that it seems too simple - however, I've yet to find an explanation that satisfies my questions, which are similar to yours. I vaguely remember seeing somewhere that the 170 was some sort of constant, but don't remember what or why. Mr. Everest, as a point of interest, about a page prior to giving this formula (and an attendant graph for various thicknesses/weights of plywood vs. depth vs. frequency, also stated that 1/2" gypsum on 16" centers had an absorption coefficient of .29 at 125 hZ, and even higher at lower frequencies - if panel size doesn't matter except for the AMOUNT of absorption, then I ask myself why it was necessary to specify 16" centers - Maybe either Eric Desart or Jeff Szymanski will see this and help us out with this - at least with the origin of the "170" part, hopefully more than that... Steve