Help me treat a square vocal/iso booth!

I built a square room. (Ducks to avoid the backlash). Okay - I know, I know. Financially and logistically it makes no sense to tear it down and start over - so I am asking for help. (I made a mistake and will explain how I got into this mess at the end, for those interested). First the room: It is 5'5" x 5'5" and 8' feet tall. There is a solid core door on the north side and there will be a 2' x 16" window on the east side (made of dual alternating size pieces of glass). The walls are 2x4 studs built like this from the inside out: 1/2" drywall - green glue - 1/2" MDF | R-13 Insulation |1/2" drywall - green glue - 5/8" drywall The floor is made of 2x4 studs, filled with insulation and sandwiched between two pieces of 1/2" MDF. There will be some roofing felt and then some pergo in the future. The ceiling is like the floor, but on 2x6 studs. O.K. - now for the help. Before I finish the interior, I was wondering if I added some narrow walls in the corners or something similar - if it would give me an advantage over simply adding normal absorption and diffusion? Since I'm not done with the interior, I do have the opportunity to alter the inside dimensions to help reduce the "squareness". I'm okay losing a few inches here or there to gain the improvement in sound. Thanks in advance for the help! (How I got into this mess: I really needed a booth. I thought I found a good solution via dawbox.com, and got started on their design (which is square). Becoming dissatisfied with their product (which I DO NOT recommend) and their service, I decided to go ahead and build my own booth. Having got pretty far and realizing (too late, I know, but hopefully someone can learn from my mistake) that I should do it right, I started hitting this, and other forums. So that's how it ended up square...hopefully with some help here though, I can alter the interior dimensions and have something workable!)

Ok - if you line it totally with a layer of 703 you will drop the reverbtime significantly but because it's a small container the frequencies around the low mids will predominate as the 703 get less efficient the lower the frequency. Plus you will have sucked all the life out of the space - i.e all the high end frequencies. Adding angled slot resonators tuned to a broadband across the low mids with reduce the low-mid problem, break up wall to wall reflections plus add highs back into the space. The other space you have for treatment is the foot of depth above you as a 7' ceiling is fine. To that area you can either add 703 off the wall or install hangers. cheers john

John, This is great info - thanks so much! And thanks for the pictures - tremendous help. Regarding the "slot resonators tuned to a broadband across the low mids"... Are there any threads you could refer me to that detail the construction on those? Or do you have any quick tips on how to go about the construction of them? Again, thanks so much!

Here's the calculator http://johnlsayers.com/phpBB2/viewtopic.php?t=1363 cheers john

Very cool. Thanks. I've read hours worth of stuff on the forum about the slot resonators, but a still have a couple questions about them. First: The current interior walls are 1/2" MDF (I was planning on putting drywall over them, but based on this new plan, I may not...). Is it okay to build the slot resonator right up against this (after it's been properly sealed) or should I put another layer of MDF as a backing? Second: The calculator is a bit confusing to me. Could you point to an article that explains how to use it, or provide a quick explanation? Thanks!

One wall will be 6" slats and the other will be 4" slats. (Based on the Blue Bear studio model). I will not vary the gaps because the slat walls are angled. One will be set at 200hz and one will be set at 400hz. I'll set the slot width according to to the materials I get to get these frequencies on each wall. Will this cover me?

now you are getting it :)

I take that as an affirmative! I should be pretty good from here on out. I may have another question two, but if not, I'll post pics when I'm done...

Hi John (and everyone else!), This is great information. I have a very similarly sized iso booth that I am going to be treating soon and have a few additional questions. If angled slot resonators arn't an option, would it be more benneficial to cover the room using FRK covered 705 as opposed to 703? It seems the 705 would help absorb more of the low mids and the FRK would help reflect some of the highs so the room wouldn't be quite as dead. Also, looking at the slot resonator/helmholz calculator from the link in this thread, one of the variables is the "depth from the wall." When building an angled slot resonator, this distance varies so what value do you use to figure the frequency of the resonator? The average? eg. If the angled resonator was 6" from the wall on one side and flush with the wall on the other side would you use 3"? Thanks in advance! Paul

yarrick19 wrote:

It seems the 705 would help absorb more of the low mids and the FRK would help reflect some of the highs so the room wouldn't be quite as dead

:?: Where did you get this idea from? Look at the absorption data for the materials. Andre

I'm thinking of doing this design but only having one wall with a helmholtz resonator instead of two. Would it be more effective to divide up the wall into two helmholtz resonators focused on absorbing different frequencies for more of a broadband effect (eg. Bottom half focused around 250 htz and the top half of the wall focused on 400 htz) as opposed to the having one whole wall dedicated to a certain frequncy? Also, how "directional" are the helmholtz resonators? If I went with something like I mentioned above and was recording a guitar cab that was low to the ground, would the 400htz resonator on the upper half of the wall still be effective?