poor boy 5.1 mixing room

I am the owner of a small town production company on a very limited budget. We recently bought a building and are trying to poorboy are way into a studio thats hopefully halfway decent for stereo and 5.1 mixing. I was hoping that someone in this forum might help me design or shape the room in a way that will keep the sound from bouncing all over the place but also keep me from going broke. I just need a simple design and maybe suggestions on where to place diffusors, sonex or traps (if I can afford any of that). I'm uneducated when it comes to this and dont have a lot of time to read about it. I hope that someone here can help me with a very simple design. my room dimensions are 16' x 18' and the room height is about 9 feet. Right now I have someone lined up to build walls for us if necessary. Just a general contractor. He suggested blowing foam insulation into the walls for starters. We just don't know how to shape our walls. Any help is greatly appreciated..

Hi "allinthemind". Welcome. Please check the forum rules for posting one more time: there's one thing you seem to have missed. :) Well, you are in the right place to find out about how to do your studio correctly! There is a wealth of solid information on the forum about that, with no hype, and no myths (you won't find any recommendations here for egg crates on the walls, or carpet on the ceiling!! : ). Just solid information based on the principles of physics and acoustics, and proven research. However, this forum is more of a "self-help" place, than a "please design this whole thing for me for free" place. Most folks who come here decide to learn how to do it right themselves, and have the time to do that: learn and design. But in your case you say you don't have the time, as you need to get this done fast. While folks here are more than willing to help those who do most of the learning and designing themselves, they aren't so willing to give out total freebies to those who can't do anything themselves, for whatever reason (as I'm sure you can understand). John and some of the members here make their living out of designing studios, so its understandable that they aren't too keen on giving away their knowledge and time. Giving free advice now and then to someone who is doing most of the design work themselves is one thing, but actually doing all that work for free is another. Especially considering that YOUR place is going to be a commercial, for-profit facility! Put it this way: When was the last time that a band you had never even heard of suddenly arrived at your studio, and said "Please record, mix, and master our album for free, as we can't do it ourselves, and don't have the time to learn how". Would you do that? So, that's my long and convoluted way of suggesting that you might want to contact John directly, and ask him to quote for designing your studio. It might be less expensive than you are imagining, if you just need something simple! (If you don't get a response from John, then PM me). Having said all that, I'll give you a bit of "freebie" anyway... :)

I was hoping that someone in this forum might help me design or shape the room in a way that will keep the sound from bouncing all over the place but also keep me from going broke.

There are two general schools of thought here: One says that the studio walls and ceiling should be carefully angled to keep first-order reflections away from your mix position. The other school says forget that, just build a rectangular room that has a good ratio, and put treatment in it to accomplish the same results, to a certain extent. Both have their pros and cons. But if you already have a room (not building a place from scratch), and you are on a very tight budget, then it might be better to go with the simple rectangular design. It is easier, cheaper, and probably requires less modification to the existing structure.

I just need a simple design and maybe suggestions on where to place diffusors, sonex or traps (if I can afford any of that)

If it is a small room (yours is), then forget diffusers: most types are not recommended for small rooms, since they create "lobing" artifacts that need a lot of space before they even out and merge. So unless your room is bigger than about 7 or 8 meters long, diffusers are not a good idea (despite the myths that you might see on the internet!). On the other hand, if it is a small room (yours is) then it WILL need bass trapping, and lots of it. That goes without saying. But you don't need to buy commercial products to do that: you can use common, inexpensive building materials, such as mineral wool (Rockwool), and fiberglass (pink fluffy stuff). Works practically the same as the commercial stuff, and much cheaper. Broadband absorptive bass traps are most effective in the corners of the room. Tuned traps are most effective at the spot where the pressure component of the specific mode that it treats, is at its peak.

16' x 18' and the room height is about 9

Ooops! Not good. It is not good to have two dimensions that are multiples of each other (18 is twice 9), or close to each other. You will have serious modal issues there, as the modal response of the room will be skewed. You might need to move one wall, or change your ceiling height, to fix that.

Right now I have someone lined up to build walls for us if necessary.

You might need to knock some down, then re-build them in the right place. Also, you didn't mention if you also need isolation ("soundproofing"), or if you only need treatment? From your post, it seems like isolation is not an issue, and all you need is to get the room sounding good, acoustically. Is that correct? (Isolation and treatment are two very, very different things).

Just a general contractor.

Red flags! Waving! Building a studio is nothing at all like building a house or office. There are difference in techniques, and if they are not done correctly, that can really wreck the isolation and/or acoustics of your room. Your contractor will need to re-learn many things in order to do this right.

He suggested blowing foam insulation into the walls for starters.

See what I mean? That's the first bad idea. Most likely the kind of foam he is thinking of is totally wrong for studios, and for acoustics in general. You need to use ONLY closed-cell foam, NEVER open-cell foam. If he cannot tell you immediately from memory (without checking the container) if it is open-cell or closed-cell, then you have a problem... That's just one of the many, many details that can sink your acoustics before you even start. The difference is that closed-cell foam is no use acoustically (although it works fine thermally) since it has no springy microscopic fibers in it, and air cannot penetrate into it and move freely through it. That makes a big difference: all of the acoustic properties of insulation depend on this microscopic movement of air throughout the material, which must also have the correct density and gas flow resistivity. You cannot just use any old material to build your studio. Yes, you CAN use ordinary building materials, but they MUST be the right ones! Use the wrong ones, or use them incorrectly, and the whole studio won't work.

We just don't know how to shape our walls.

Well, we can help a bit there too! There are known good shapes, angles and dimensions, but to get those right we need to know a lot more about what you plan to DO in there! Is this for recording really heavy death-metal rock bands, or for recording a single piccolo? slight difference.... :) Anyway, contract John (or PM me if you can't get hold of him). - Stuart -

Thanks for this! I am interested in hiring someone to help as long as its not thousands of dollars. I didnt know if it was against forum rules to offer money for design help. I really appreciate this response and all the info you have provided. I'll do some research here and then contact John. Sorry for my ignorance on these matters. Thanks again Stuart!