Intro/design posibililties?

Hey everyone, First off let me introduce myself. My name is Matt and I am a Senior studying Structural Engineering at Virginia Tech. I am minoring in Audio Technology/Music Production, and am very interested in going for my masters in Architectural Acoustics. I am a musician (I play guitar) as of 10(ish) years ago. Now, to the main reasons I found this forum. haha sorry in advance for the lengthy post. First off, I am looking to try to find an internship/Co-op opportunity within an acoustics-related field for next year. I did some research and have quite a long list of companies around the East coast of the US. I know this is an Australian based forum, but was wondering if anyone happened to know of any one/companies/firms that I could possibly try to get in touch with around the Washington D.C. Area? Secondly, My friend is the president and Editor in Chief of a local publishing company (they print one of the campus newspapers, along with magazines, and try to get some local music artists some marketing and recognition). Recently, they found a few local bands who have producers who have been recording in garages/basements with a portable soundfield running through a computer. They have been working with the artists and recently received the "ok" and partial funding for building a mini studio within their production building. My friend came to me and wants me to design the space (they aren't using professionals because they cannot afford it and it is a relatively small space) for proper recording. She wants to give me the opportunity for a resume builder, experience, and a little extra cash. I told her that I would love to design it and work with them to get it all set up, but I need a few pointers if possible. I have access to a full sized professional recording studio, so I know the basics. I understand the need and use of absorbing materials, diffusers, bass traps (if needed), and the basics of the architectural side of things. I just want to know what you all think I should start looking at to know where to start and how to design it. I haven't seen the room, but I am expecting a mid-sized rectangular room from what I have heard, and am planning on sectioning one area off as a control room, and keeping the rest as a rectangle for the recording room. I dont want to try to mess with all of the properties of un-parallel walls my first time doing this, and I know how to control a flutter echo and standing waves in the space. I was basically wondering what you all think I should start looking at and researching in order to make the best that I can with the knowledge I have/can learn by when I need to start designing. I was planning on keeping it rectangular (as stated) and was planning on making the control room a LE/DE room. The main room was going to be wood (no plasterboard). The wall across from the control room window was going to be designed as a diffuser, and some baffles would be located on the other two. I would be building a Diaphramatic Absorber as well if it is needed to control low frequency noise. Where should I start with my research and planning/do you all have any tips for a first-timer who is working on a budget and creating a space for more commercial use as opposed to high grade professional use? Thanks!

Download Google Sketchup and start playing with it and show us pictures. What are the dimensions of the space you have to work with?

Hi Matt, and welcome! Like Eric said: Photos, dimensions, and an accurate 3D model of the space you have available would help greatly! Without that, nobody here has any idea of what you are dealing with. YOU can see it, but WE can't unless you show us! :) A few comments on your post:

I understand the need and use of absorbing materials, diffusers, bass traps (if needed), and the basics of the architectural side of things.

Ummm.... you seem to have things a bit backwards! It is a small room, so it WILL need bass trapping. That is a given: all small rooms need bass trapping. There simply is no question about that. On the other hand, most small rooms CANNOT successfully use most common forms of diffusion, due to the distance that it takes for the lobing effects of most types of diffuser to even out again. The use/non use of diffusers can be decided once you have the dimensions of the rooms clear, but for small rooms, it probably wont be a good idea. Especially in the control room! In other words: It is absolutely certain that you will need bass trapping, simply because your rooms will be small. It is highly unlikely that you will be able to use diffusion successfully, simply because your room will be small (unless great care is taken in selecting, designing and building the devices).

I just want to know what you all think I should start looking at to know where to start and how to design it.

I'd suggest that you start with the books "Master Handbook of Acoustics", by F. Alton Everest, and also "Home Recording Studio: Build it like the Pros", by Rod Gervais.

I haven't seen the room, but I am expecting a mid-sized rectangular room from what I have heard, and am planning on sectioning one area off as a control room, and keeping the rest as a rectangle for the recording room. I dont want to try to mess with all of the properties of un-parallel walls my first time doing this, and I know how to control a flutter echo and standing waves in the space.

There are two schools of though here (as you probably know): one says that splaying control room walls for LEDE or RFZ design (or even CID) is the only way to go, and I kind of lean that way myself. The problem with that, of course, is that it is pretty hard to accurately predict modal behavior for non-rectangular rooms, so the other school of thought says that rooms should always be rectangular, then treated. But of course treating a rectangular room to create the RFZ or CID concept is really hard, and requires lots of careful calculations for all those angled surfaces. So, as with most things related to acoustics, its a trade-off: Do you want to make it hard to calculate modal behavior but easy to figure RFZ? Or do you want to make it easy to figure modal response but hard to figure RFZ? Your call! :)

I was basically wondering what you all think I should start looking at and researching in order to make the best that I can with the knowledge I have/can learn by when I need to start designing.

There simply ain't no better place on the entire internet than right here, on this forum! That's a pretty big statement, but after you start looking around and reading through the threads, you'll find that it really is true. To start with, there is no marketing hype allowed here: nobody will try to sell you on a particular brand of product (even though people from several major manufacturers do post here, occasionally). If a product or technique is recommended here, it is because there is broad, independent, published scientific research to back up the claims, and it has also been tested in numerous real-world studios and shown to work. Next, you won't find any myths and legends here: no "egg crates on the walls, because my friend did that in his place" ( :shock: ). No "carpet on the ceiling because I saw it in a photo of a studio once". ( :!: ). What you get here is just solid, down-to-earth proven acoustic principles, products and techniques.

I was planning on keeping it rectangular (as stated) and was planning on making the control room a LE/DE room.

The LEDE concept hasn't been used much in years. It was found to not be all that it was cracked up to be, and the more modern replacement is RFZ. Far superior.

The main room was going to be wood (no plasterboard).

I thought you said that the budget was limited? In most places around the world, wood is rather more expensive than drywall. Sound waves don't care how much you pay for your mass: they don't read price tags, and only react to the mass in front of them... So get the cheapest mass you can. :)

The wall across from the control room window was going to be designed as a diffuser,

If we are talking about the control room, that would be a bad idea (assuming that the window is on one side of the room). For a control room, symmetry is fundamental. Without room symmetry you cannot get an accurate stereo image, your sound stage won't be centered, and your mixes wont translate well.

Where should I start with my research and planning/do you all have any tips for a first-timer who is working on a budget and creating a space for more commercial use as opposed to high grade professional use? Thanks!

Look around! Grab yourself a large mug of the beverage of your choice, put your feet up on the desk, and start reading through some of the build threads here. Follow all the links, make lots of notes, and take your time. This place really is a gold mine of solid, sound (excuse the pun!) information and advice on all aspects of acoustics. - Stuart -

Also, start out with John's Recording Manual http://johnlsayers.com/Recmanual/index.htm I can't second enough the Master Handbook of Acoustics. http://www.amazon.com/gp/product/0071603328/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000T3P3M8&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=082YRCEZ3BZ4XRBJVJS6 At this price it is a steal! First place I always look when I don't know an answer. There is some math in there, but nothing more complex than High School Algebra (with you major, non-issue). Then have Rod's book tell you how to build it. I am also a fan of Phillip Newell's books and design philisophy, but this is not universally shared (I think because a lot of people think his "Non-Enviornment Rooms" are only for large spaces and are the same as the "dead rooms" that were tried in the early seventies and didn't work so well). He has written numerous books including one dealing with small "project" Studios. They are more a little more complex then the previously recommended but not much. I wouldn't go to these until you have scoured The Master Handbook of Acoustics. I miss knightfly, he was the other Newell fan around here! Now I am alone. :( Also, don't be afraid to post something if you are not sure it is correct. You will be challenged, but don't back down if you don't understand or think you are right! Debate is a great learning tool as long as we don't get nasty :mrgreen: Never blindly accept! Most importantly, have fun!!!!!!!!!

Thanks for the clarification Stuart. I was thinking that being a smaller room wouldn't allow for the wavelengths of bass frequencies to resonate much so there wouldn't be much of a need for bass trapping. I have a book called "Architectural Acoustics" By David Egan that I bought last summer when I was doing some undergrad research in HVAC noise control and flanking paths between rooms. I have read through some of it (though not nearly all) and plan on doing that, but wanted to get some extra information as well. I will see if I can find either (or both) of those books somewhere and start my homework! I'm unfortunately unfamiliar with the "RFZ" concept.. could you possibly explain this to me? or link me to a notable source? I was thinking wood vs. plasterboard because since it is - more or less - porous, it would lessen the reflections within the space. I didn't even think about the cost.. my bad. hah is there a tried and true method of controlling early reflections and echos caused by plasterboard? I feel like I may be making this out to be much worse of a problem in my head than it actually is... I have already found that this site is a wealth of knowledge. I know I will be referring here whenever I have problems/want to learn more. Its great to know I have access to all of the great professionals out there. Thanks for all the advice! Oh, one last thing. I dl'ed SketchUp but can't figure it out for the life of me. Is there a good tutorial out there somewhere that I can look at?

The RFZ or "reflection free zone" is used in many ways. This is a diagram of what is though of as the classic RFZ The idea is that with the walls angled, all of the first reflections go past the mix position creating a "reflection free zone." These reflections go to the diffuser in the back and are scattered back in to the room. For smaller room the diffusion at the back isn't practical so most put absorption in the back. The angles for the RFZ also have to include the ceiling making this difficult to do with a low ceiling height. Most low ceilinged rooms will use absorption "clouds" over the mix position to absorb the reflections. (I have some crazier ideas that I am going to try to implement. A few here think they will work great, a few don't.http://www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=16887 The control room on the second page is done to scale.) You can create a reflection free zone in a rectangular room using asorbers.

Thanks for the clarification Stuart. I was thinking that being a smaller room wouldn't allow for the wavelengths of bass frequencies to resonate much so there wouldn't be much of a need for bass trapping.

Maybe you are confusing RT-60 and resonant field with standing waves and bass build-up? You are correct that small rooms cannot really have a diffuse resonant field for low frequencies, so talking about RT-60 for small rooms is not really technically valid, but bass still does build in small rooms, and since small rooms do not support many resonant modes (OK, make that "standing wave modes", to be more correct), the issue is that the modal spread is not even, and is very evident. In acoustically large rooms, this isn't so much of an issue, since the room already supports multiple modes and actually can build a resonant field, but with small rooms you end up with just a few isolated modes, spread out unevenly across the spectrum. Those need treating. Of course, you can't really "kill" a mode with treatment (the mode will still be there), but you can absorb some of the energy and damp the modes somewhat. So small rooms will always need bass trapping, and lots of it.

I'm unfortunately unfamiliar with the "RFZ" concept.. could you possibly explain this to me? or link me to a notable source?

RFZ is Reflection Free Zone. The concept is simple: splay the walls so that no first-order reflections arrive at the listening position within about 15 ms or 15 dB of the direct sound. So you angle the front/side walls and the ceiling to force the first reflections behind the listening position, and/or also treat other first reflection points with absorption. You don't want anything at all hitting your ears until at least 15 ms after the direct sound arrives, and even then it should be 15 dB below the level of the direct sound. That's the general idea.

I was thinking wood vs. plasterboard because since it is - more or less - porous, it would lessen the reflections within the space.

The difference is minimal, I reckon. I haven't looked into it much, but untreated wood is pretty porous too! In any event, are we talking about isolating your room, or treating it? Two different concepts. The wood or drywall (plasterboard) would most likely be part of your room isolation ("soundproofing"), but isn't used much in treatment (except maybe for panel traps, and some types of diffusion). Have you figured out how much isolation you need? That's normally the first priority. Measure (with a sound level meter) how loud you are and how quiet you need to be. The difference between the two is how much isolation you need, expressed as dB of Transmission Loss (TL). That number will dictate the type of construction you need to put in place to obtain that level of isolation, and that in turn will dictate the inner dimensions of the room, and the treatment (to a certain extent).

is there a tried and true method of controlling early reflections and echos caused by plasterboard?

Yup! Put it at an angle, so that the reflections don't get to your ears! (Sounds easy in theory, not so easy in practice): You can use ray-tracing to figure that, but there are some general rules of thumb. For those places that cannot be angled suitably, a second-best is to treat them with thick absorption, spaced away form the wall for maximum effect.

I feel like I may be making this out to be much worse of a problem in my head than it actually is...

That all depends on how bad it is in your head!!! :) :) Seriously, it might be easy, or it might not. The shape and dimensions of the space that you have to work with have a lot to do with that. For very small rooms, it might not be easy to get the listening position, speaker geometry, wall splaying, first reflection treatment and modal behavior to all play together nicely. Generally, the bigger the room the easier it is.

Oh, one last thing. I dl'ed SketchUp but can't figure it out for the life of me. Is there a good tutorial out there somewhere that I can look at?

Yeah, it takes a while to get your head around the concepts of SketchUp initially, but once it "clicks", you'll find that it is a really powerful and useful tool (with some strange quirks...). Try googling "sketchup tutorial" :) Edited one minute later to add: Damn! Eric beat me to it! :oops: :) - Stuart -

Well I got RFZ, but you got everything else :D

Well, it seem that I have a lot more to learn than I thought. haha oh well. Should be a fun journey! The RFZ concept actually makes a lot of sense to me, and as crazy as it is I was actually thinking of what would happen if I made an area somewhat designed like that. I was thinking more of a semi-circle at the end of a trapezoid (if that makes any sense). I was thinking the drywall for more just isolation. I would be building some baffles and treatment boards to deal with the reflections and add absorption to the room. Like I said before, I still haven't seen the space (hopefully sometime this week) and am still waiting for an email back with more specifics (like location, dimensions, etc.) so right now I'm still in just the very pre-planning phase. Just trying to wrap my head around everything, and listen and learn about whats best and how to make this work. Now to just figure out what to do with SketchUp.. haha I will try googling and playing around with it for a while.

vthokies wrote:

I have a book called "Architectural Acoustics" By David Egan

Have that one as well, Harold Lord "Sound control for Engineers, etc. etc., you really want to get the Master Handbook of acoustics, Everest. He speaks directly in a no nonsense fashion and breaks down every aspect, down to the smallest degree, of everything you are going to be dealing with in an acoustic environment. And it costs far less than any book you may have purchased to date in learning your field.