John Sayers' Recording Studio Design Forum Archive

Hello all, I have read all the rules and guidelines so hopefully I am doing this correctly. Please forgive me if I am not

I am a bedroom producer and am looking to further improve my listening environment by acoustically treating my room. My budget is anywhere between $500 - $1,000 but I am willing to save up more if need be. I will be producing all the panels DIY with insulation. I also plan on recording in the same space as well but my main priority is getting the best listening environment possible. My mixing an listening volumes are usually anywhere between, 60 - 90 dB (C weighted).

I am seeking advice into acoustic treatment for my room, and also need a bit of help interpreting my REW graphs.

The Room

I am currently set up in a cove with no rear wall. It is 13' 6" to the opening of the cove, 8' 2" Wide, 8' from floor to ceiling. The cove opens up into a decent sized room, the total space of the whole area is 600 sqft. There is also a 45 degree bezel that runs along the top of the entire room.

Here is an album of the whole room including all measurements.

http://imgur.com/a/5yCNI

Monitor Placement

My monitors are KRK 8's. They are currently set up 42.5" from cone to cone in an equilateral triangle. Placed 17" from the back wall and 39.5" from each parallel wall on the sides. Tweeters are 3' 8" from ceiling and cones are 4' 3" from ceiling (So if I did my research right they shouldn't be in a null?). My listening position is at the 33% mark from the short corner side of the cove if I were to have a back wall (13' 2"). I do have a 10" KRK sub as well located under my desk.

REW Graphs

My readings were done with a Nady CM-100 from my mixing position exactly at the point where the monitors meet in the equilateral triangle with both monitors on. I am not sure what to post for the graphs so please let me know if I am missing anything or if more readings of my room are necessary. I would be more than happy to provide them. Also, if you need readings with just one monitor at a time.

Full graphs of Shots 1 and 2
http://imgur.com/a/AwR0Y

40hz - 500hz Shots 1 and 2
http://imgur.com/a/Sgwl3

I am not sure what settings I should use for my waterfall graph hopefully this suffices, if not let me know and I will update it quickly.
40hz - 500hz Shots 1 and 2
http://imgur.com/a/Sc0Qx

I have also included the master test file.

Please forgive me for any mistakes or formatting issues, and correct me on what needs to change in the future!

Thank you so much for your time,
Steven

Edit: For some reason I couldn't use the attach file feature for my Master REW readings so I have provided a dropbox link instead.
https://www.dropbox.com/s/xx3cu1qlhv79b ... .mdat?dl=0

Hi there Steven, and Welcome!

The Room...

We'd need to know a lot more about how the room is treated at present. The REW data isn't grossly terrible, but it's also nowhere near fantastic: There's some major issues in the low end, with large swings in levels, some modal activity, floor and ceiling bounces, desk surface issues, etc., but without knowing what you already have in there, we can't really help you with what else you need to do. Please explain what treatment you have, including how it was made and what materials were used to make it.

That said, the first thing you'll have to do is to get all the unnecessary stuff out of there, and clean it up to get proper symmetry and proper geometry. Take out the sofa on the right, the side table on the left, the video screen in the front left corner, the "things" standing up against the right wall, and all the other stuff. All of that has to go. The room has to be bare to start with, for your treatment, and it has to stay that way after it is treated. Symmetry is critical, so you can't have anything on one side of the room that is not matched by something identical on the other side.

Take it all out, and leave just your desk with the DAW on it, and your speakers.

They are currently set up 42.5" from cone to cone in an equilateral triangle. Placed 17" from the back wall and 39.5" from each parallel wall on the sides.

That needs to be fixed! That's probably the source of some of the problems visible in your REW data.

It also doesn't make sense! You said the room is 8'2 wide, which is 98". If they are each 39.5" from the side walls, then they cannot possibly be 42.5 apart! 39.5 + 39.5 + 42.5 = 121.5 = 10' 1-1/2". so there's something wrong with your math here... From the photos, it looks like the room is about 8' wide, not 10' wide, so I'll assume that the 8'2" is correct and your numbers for the speaker positions are wrong.

Set up your speakers so they are tight up against the front wall, with just a 4" gap between the rear corner of the speaker and the front wall. That gap is for you to put in a 4" thick panel of OC-703 later, between the speaker and the wall. Therefore, the rear corner of the speaker will be touching the front face of the 703 after you do that (see below).

The speakers are too close together, and angled incorrectly. Move them further apart, so they are 28" from the side walls- I'm talking about the location of the acoustic axis here, not the sides of the cabinet. The acoustic axis is the imaginary point on the front baffle of the speaker, from which the sound appears to emanate. It should be indicated in the speaker manual, or on the manufacturers website. If not, you can estimate: it will be on the imaginary line that joins the center of the woofer to the center of the tweeter, and it will be much close to the tweeter than the woofer. Probably around the point where the tweeter waveguide meets the front baffle. Imagine a line that pokes out from that point on the speaker, perpendicular to the front baffle: that is your acoustic axis, which you will use for aiming the speaker. So set up the speakers such that the acoustic axis of each is 28" from the side wall. That will put the axes 42 inches apart. (28 + 28 + 42 = 98" = 8'2" )

Now set up a mic stand perfectly vertical, on the room centerline, exactly 60" from the front wall, and set up your chair so that the center of your head will be 46" from the front wall. The mic stand is just there as your aim point. Aim each speaker so that the acoustic axis is pointing exactly at the mic stand. Use a laser on top of the speaker, centered on the acoustic axis, if you want extreme accuracy.

Now also make sure that your speakers are set to the correct height: 47.25" above the floor. Once again, that's the height of the acoustic axis, not the cabinet. In your case you could go a bit higher, but no more than 49".

Your speaker stands don't look very substantial, so I'd suggest replacing them with something heftier. They need to be massively heavy: Many people build them from steel and fill them with dry sand to get the mass. You should also use Sorbothane pads under the speakers, to decouple them from the stands. Allow for the thickness of the Sorbothane when building your stands, so that the height works out correctly.

That sets up the correct geometry for your room. Do one set of REW tests (explained below) like that, with no treatment in the room, then do another set once you get the basic treatment in (see below)

REW Graphs

My readings were done with a Nady CM-100 from my mixing position exactly at the point where the monitors meet in the equilateral triangle with both monitors on.

That needs to be fixed too! The mic is fine, but the rest is no. The mic must be set up exactly where the center of your head will be, not at the point where the axes intercept.

Yes, I know that you've seen that famous diagram on the Internet, copied and repeated everywhere, showing the famous "triangle" with the apex in the middle of your head. I don't know where that came from originally, but it is wrong. It does not apply to humans! If you look at that diagram, you'll notice that the speakers are aimed at your eyes! So that would work out well for all people who have had their ears surgically transplanted into their eye sockets, but for the rest of us, the speakers should obviously be aimed at our ears, which stick out on the sides of our head, a few inches away from the middle of our brains... In fact, research shows that even that aim point is too far forward: it should really go about 12 to 18" behind your head, with the axes grazing past the side of you ears, not actually touching your head at all. That's why your speakers will be aimed at that mic stand, 60" from the front wall and 14" behind the center of your head. That's the optimal location to get a good wide sweet spot, proper stereo imaging, and a clean, broad, accurate sound stage.

Therefore, the place where you set up the mic is the spot that is mid point between where your ears will be, which is NOT the same point as where the axes intercept.

The mic also needs to be pointing forwards, exactly between the speakers, but angled upwards towards the ceiling at 60°.

Do your REW tests like that. Carefully measure the exact location of the mic in the room, in all three dimensions, so you can always get it back to that precise point for all future measurements. This is important! It MUST get back to that exact spot, accurate to within 1/4", for ALL measurements.

I am not sure what to post for the graphs

Just the actual MDAT file, unless you spotted something that you think is important in one of the graphs, then post that as well.

From the graphs, it is apparent that you did not calibrate REW correctly, using a good quality hand-held sound level meter. You need to do that. Calibrate REW at a level of 77 dB(C) for each individual speaker. In other words, first set all your gear to flat response, no EQ anywhere, no dynamics, nothing but a clean signal path going in and out, with the gain structure set correctly all across the system at -20dBFS (and/or 0dBu), so there will be good S/N and no clipping.

Now turn off the left and right speakers leaving only the sub on, play the sub calibration signal in REW, and set the sub volume control so that you see a level of 77 dB(C) on your hand held meter (set to "C" and "SLOW") when you have it in the mix position. Now turn off the sub, turn on only the left speaker, and do the same, setting the volume control to get a level of 77 dB(C), but using the speaker calibration sound, NOT the sub calibration sound: Now repeat for the right speaker alone, at 77 dB(C). Now turn them all on together, and you should be getting a level of a bit over 86 dB(C), which is the "standard" calibration level for cinemas and studios. With that level playing in the room and visible on your meter, use the SPL calibration tool in REW to tell REW what the real level in the room actually is. That's the only way that REW will know what the level is. After you calibrate, you should see 86.5 dB on your hand held meter, and 86.5 dB on the REW meter. When you see them both showing the same number, you have calibrated correctly.

Now do your actual tests. We need a set of seven tests initially, to get the full picture of what the room and the speakers are doing. Do all of these with full spectrum sweeps, from 17 Hz to 22,000 Hz. For each test, set the delay to a time that is long enough for you to get out of the room completely, plus 5 seconds.

Do one test with just the sub on, and label it "--S Empty", one test with just the left speaker on and label it "L-- Empty", one test with just the right speaker on and label it "-R- Empty", one test with both the left and sub on, labelled "L-S Empty", one with both the right and sub on, labelled "-RS Empty", one with just the left and right speakers on but no sub, labelled "LS- Empty", and one with all of them on together, labelled "LRS Empty".

Then put the initial basic treatment in the room, and do another set of tests, following exactly the same procedure, but changing the "Empty" to "Basic" for each label.

The "initial basic treatment" is:
- One "Superchunk" style bass trap in each front corner, floor to ceiling. Make them as big as you can, at least 18" on each side, and hopefully 24".
- One panel of 4" thick OC-703 behind each speaker, up against the front wall. Make the panel big enough to extend from about 6" below the level of the desk surface to about 2 feet above the top of the speaker cabinet, and wide enough to extend at least 16" each side of the speaker. That implies that these panels will meet the edges of the superchunks on the wall side, and will nearly meet in the middle of the front wall, being about 10" inches apart.
- One panel of OC-703 on the ceiling, centered midway between the front baffle of the speaker and your ears.
- One panel of OC-703 on each side wall, centered midway between the front baffle of the speaker and your ears.

Post the REW MDAT file after you complete all of the above, and some photos of how the room with all that treatment in place, then we can help you with your next round of treatment, and adjustments of the speakers.

- Stuart -

First of all, thank you so much for the very thorough reading Stuart. It means a lot to me that you'd write so much out just to help me out!

I have read your post about 5 times now and noted all that you said. I will begin working on it in a few hours when I am back home from my day job. As for current treatment, I don't have any whatsoever. I threw as much soft stuff (pillows, blankets, futons) in the room as I could to try and deaden reflections a bit but now that I have an idea of what I should shoot for, I am clearing it all out this afternoon.

That was a typo on my part, the room is actually 10' 2" wide so the speaker measurements are accurate within a 1/2". Do you still suggest that I space them out farther apart? I will be rearranging everything today so they will be 4" from the wall to the cabinet. I just need a better idea of how far to keep them apart. I plan on getting some better stands or possibly welding some up at my dads shop. I can order the sorbothane pads as well as a new SPL Meter today unless you think these are substantial, which I have at the moment.

https://imgur.com/a/K2F73

I will be updating this post as frequent as I can get all of this stuff taken care of. Once again I really appreciate the response.

That was a typo on my part, the room is actually 10' 2" wide so the speaker measurements are accurate within a 1/2". Do you still suggest that I space them out farther apart?

Yes, definitely.

For 10'2 width, set the speakers 34" from the side walls, making them 54" apart. The rest stays the same.

Yes, that does mean that the speakers will not be angled inwards at 30°... because that's another myth! There is no reason why they should be set at exactly 30°, nor is there any good reason why the distance between the speakers should be same as the distance from each speaker to your ear. So why do so many places on the Internet get that wrong? Good question... no answer... just "perpetuated myth", i guess. They all quote each other, without thinking about what they are saying...

Anyway... Forget the famous "equilateral triangle at 30° angles" (unless your ears really are located in your eyeballs!)

What matters is symmetry, distances, and a reasonable angle. "Symmetry" in the sense that the distance from the left speaker to your left ear should be the same as the distance from the right speaker to your right ear, but there's no logical reason for that to be the same as the distance between the two. The ONLY reason I can think of is that it makes it easy to measure, and guarantees an equilateral triangle... So simple people can set up simply.... and get simply awful acoustics!

And also "symmetry" in the sense that the left half of the room must be a mirror image of the right half of the room, no exceptions.

Same for angles: You'll often hear "you must angle your speakers at 30°" chanted as a mantra, almost as a sacred religious law of the universe... but with no actual basis in reality. In real life, you can have pretty much any angle you want between about 20° and about 45°. All that changes is the shape of the sweet spot, and the width of the sound stage (plus some psycho-acoustic effect). It is possible to go even greater without the universe crashing to an end, but with caveats: If you want a super wide sound-stage but little width to your sweet spot, go with a massive 60° angle. Amazing sound-stage. But do make sure to keep your head bolted in place, as your "sweet spot" is razor thin! Even slight moves of the head to left or right will degrade it, fast. On the other hand, you can move your head front to back a huge amount with this setup, and still have the exact same image. At the other extreme, with an angle of say 15°, your sweet spot is wonderfully wide, but the sound stage is more compressed and mashed together.

It's all about trade-offs, not absolutes.

In other words, there's a large range of possible angles, and you can use any one that you happen to like, as long as you understand the consequences, and it meets your needs. In the vast majority of cases, an angle of about 25° to 35° is excellent, and 20° to 45° is usably good. 30° is about in the middle of that range, so it is among the good ones, but that's all it is. There's nothing magical about it. Your ears work really well through 360°, and there's no preferred angle that they "like" to hear sound coming from... as long as the sources are on the "horizon", your ears and brain can do an amazing job of figuring it all out. The world won't spiral into the sun if you happen to have your speakers at 29° or 31°, instead of the sacrosanct 30°, and you won't get arrested by the "Speaker Police"...

Of course, in addition to changing the angle, you can also move your speakers closer together or further apart at the same time, to get an even broader range of possibilities. Speakers that are far apart and set at large angles provide better sound-stage but narrow sweet spot, while speakers set close together at smaller angles provide wider sweet spot but narrower sound-stage. Etc.

Then there's the room acoustics to consider as well, and that's usually a far bigger thing than most people think. You can have great speakers, but set them up at lousy locations in a badly treated room and they will sound terrible. You can also have mediocre speakers, but set up optimally in a well treated room, they can sound pretty darn decent.

So how do you navigate through all that and figure out what is best for your room? There are equations and charts and graphs and rules of thumb and experience... all of those come into play when figuring where to put the speakers. The set of numbers I gave you is a good compromise for your room, and should work well. I don't even know what angle that will work out to, and to be honest, I'm not worried. It will be close to 30°, definitely greater than 20°, and definitely less than 40°, so I'm not worried. What's important here is the geometry: where your speakers are located with respect to the walls, where you head is located, and the point that the speakers are aimed at. That's why I gave you distances, not angles.

Actually, when I design control rooms, I start with the speakers and build the room around them! After all, the speakers is the reason why the room exists at all! If there were no speakers, there would be no need for a room! So it makes sense to look at the characteristics of the speakers that the engineer wants to use, and design the room around those, positioning them in the room at the optimal location, distance and angle, then providing optimal treatment for the room, then doing the final tweaking and tuning.

Here's what happens when all of that is done right: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471

That's about as close to acoustic perfection as you can get, realistically.

I can order the sorbothane pads as well as a new SPL Meter today unless you think these are substantial, which I have at the moment.

I would go with Sorbothane. There's nothing better. the speakers in the room at the above link are mounted on Sorbothane. Actually, there's a rather complex mounting system for those speakers, that fully "floats" them inside the soffits, and is carefully tuned to have a resonant frequency way below the cut-off.... and all of that is done with Sorbothane. It's amazing stuff.
Check the Sorbothane website:I think they sell special "feet" that you can stick on the bottom of your speakers. They used to offer those for different weights of speaker. Not sure if they still do. If not, then I can figure out what product you need to get from them to work with your speakers. It's all about weight, surface area, deflection (compression), and resonant frequencies. Let me know if you can't find their "speaker feet" thingies, and I'll do the math for your KRKs.

I will be updating this post as frequent as I can get all of this stuff taken care of.

Cool!

You can do the initial tests with your current speaker stands and pads, provided that you can adjust that to the correct height. Then you can do another set of tests once you get the massive stands and Sorbothane pads.

Why all the hassle with speakers stands? Because this actually is a real thing. If the stand is not massive enough, and not decoupled, then it can transmit the speaker vibrations right into the floor, which then acts as a speaker itself. And because sound travels much faster in solid things like steel and floor wood as compared to the speed in air, the muddy sound from all that can actually get to your ears before the direct clean sound form the speakers... totally trashing your ability to hear clearly what is in the mix. Having a massive stand with a good, soft, well-damped, decoupled pad to float the speaker on, means that none of the above happens: the speaker can shake, wobble, roll and vibrate to it's hearts content, and none of that will get into the stand. The rubber decouples the speaker at all frequencies above 1.4 times the resonant frequency of the system. As long as the resonance is tuned way below the lowest tone that the speaker can produce, there's no flanking. And the result is clean sound. The stand has to be massive, because the entire system is what physicists call a "Mass-Spring-Mass" system. The first "mass" is the speaker, the second "mass" is the stand, and rubber pads are the "spring". It is a tuned system. The more massive you can make the stand, the lower the resonant frequency goes. And you want it low. Really low. The reason why Sorbothane is the best for this, is because it isn't just a spring. It is a damped spring. The composition of Sorbothane produces extremely good damping of vibrations. It's crazy stuff. If you drop normal rubber on the floor, it bounces, but Sorbothane doesn't: it just sort of "flubs" and stays there, because it absorbs all the energy of the impact internally and converts it into low-grade heat at the molecular level. Normal rubber stores the motion energy then release it again as motion: it bounces back. Sorbothane stores the motion energy then turns it into heat. No bounce. It absorbs shock,vibration, and motion incredibly well, which is why I'm such a big fan of it for speaker mounts. Neoprene rubber is another good one, and so is EPDM, but they aren't as good as Sorbothane.

Sorry for sounding like an infomercial for Sorbothane! I just love the stuff for acoustic applications.

And sorry for the long, bring explanations, too! But I find that it often helps when you understand why you are doing specific things as you set up your room, rather than just following instructions blindly. If you understand the reasons behind it, then you'll do a better job of getting it right, and won't make silly mistakes that you might have made otherwise.

Once again I really appreciate the response.

That's what we are here for!

(Actually, you also got a bit lucky: I had a few minutes to kill while I was waiting for a reply from one of my customers, and I happened to see your post right then...)

I'm looking forward to seeing the data from the empty room: that will show you just how bad the real situation is, but it also reveals where all the problem are, in their full ugly glory, which makes it easier to fix them.

- Stuart -

Alright I cleared out the whole room today and readjusted my speaker stands for the time being! I haven't got to order my SPL meter or anything yet, so I am going to order it with my CM-703 next Friday. I have done the math and it comes out to roughly 40 sheets plus or minus I will have a better number after I figure out some of the final questions below . My father is a contractor so he is calling around trying to find the best deal he can on the 703. I have a few more questions before I put my orders through though.

1. For my first reflection point panels and my cloud panel should I have them 4" thick or 2" thick?

2. As for Sorbothane I found a few different choices on amazon. Should I some pads on sub woofer as well? It is on carpet.
I was thinking I should go with these as they state Supports between 5 lbs and 10 lbs per pad. My speakers weigh 26.5 lbs, so that would come out to 6.625 per pad on weight distribution. Which I think is the correct way to do it if I did my research correctly.
goo.gl/SOjcuH

3. For the bass traps they are 24 x 24 x 31 (Hypotenuse) correct? And also I can't make them reach the very top of the ceiling because of the angled piece, any suggestions about that? With those measurements (24 x 24 x 31) they would run about half way up the angled piece.
https://i.imgur.com/aloXcXo.jpg

I plan on building them to run up into the angled piece as high as they can go at the size 24" x 24" x 31" I hope you know what I mean
http://imgur.com/a/jcA7i

4. What material should my stands be made of and how massive should the stands be? Specially what the Sorbothane should be resting on between the speakers?

6. Also should I be covering anything on the angled bezel with treatment?

7. How wide should the cloud be above my head? The flat part of the ceiling is 6' 2" wide so should I just have it cover the whole flat part until it hits the angle point?
http://i.imgur.com/7lXNEWQ.jpg

Also, the pad directly behind my speakers will run from bass trap to bass trap because I cannot go 18" past the speakers as they will run into the bass traps. It will end up effectively covering the whole wall minus the section from 6" under the desk.
(Sorry for my awful paint skills, nothing is to scale.)
Edited version : http://imgur.com/a/RZLwb
Clean version : http://imgur.com/a/Qtm2y

You mentioned nothing about having not having a rear wall so I am assuming this isn't too big of a problem as well.
Lastly, any suggestions on what I should use on the frames for my panels and bass traps? 2 x 4's or 1 x 4's? I am thinking I will be wrapping them in burlap as well.

I think those are all my last questions before I go ahead and get started on the project. All orders are to be made when I get my next paycheck on Friday and I will begin when everything arrives!
Thank you yet again for all the help, sorry for my terrible formatting and such.

1. For my first reflection point panels and my cloud panel should I have them 4" thick or 2" thick?

I would go for 4" thick.

2. As for Sorbothane I found a few different choices on amazon. Should I some pads on sub woofer as well? It is on carpet.

Carpet! Darn! I missed that. IT completely slipped my mind to ask about your floor. In general, carpet is not a good choice for studio floors. It does the opposite of what you need in most small rooms. If you look at photos of professional studios, you almost never see carpet on the floor, and it's for a very good reason: Carpet absorbs highs and high mids very well, absorbs low mids randomly and unpredictably, and does not absorb low frequencies at all. Small rooms need the exact opposite: lots of absorption in the lows, careful controlled absorption in the low mids, much less in the high mids, and nothing in the highs.

Your situation is a little different, since that seems to be fitted carpet, that you likely don't want to take out, you have no rear wall (so there are two "zones" to your room acoustics), and you also have that interested bevel around your ceiling. I would leave the carpet in for now, and we'll so how it goes. In the worst case, you could cover it fairly easily with thick plywood then lay laminate flooring on top, but hopefully it won't come to that.

So going back to your question: If the sub is sitting on carpet, then you don't need pads for it, but if it is sitting on a hard surface, then yes, I would put pads under it.

I was thinking I should go with these as they state Supports between 5 lbs and 10 lbs per pad. My speakers weigh 26.5 lbs, so that would come out to 6.625 per pad on weight distribution. Which I think is the correct way to do it if I did my research correctly.

3. For the bass traps they are 24 x 24 x 31 (Hypotenuse) correct?

I can't make them reach the very top of the ceiling because of the angled piece, any suggestions about that? With those measurements (24 x 24 x 31) they would run about half way up the angled piece.

That's fine. No problem. That beveled cornice is an interesting thing: It will probably work in your favor for low frequencies, to a certain extent, but less so for mids.

4. What material should my stands be made of and how massive should the stands be?

Make them as massive as you can. Some people use large section steel and fill it with sand. Other people stack up bricks or concrete block, then put fabric around them to make them look good. Some people use PVC sewer pipe standing vertically attached to a sold base, filled with sand. Etc. The actual platform on top of the stand that the speaker sits on should also be solid, rigid and massive: steel plate, concrete paving tile, thick solid wood, etc. The idea is to make it very solid, very massive, very rigid.

6. Also should I be covering anything on the angled bezel with treatment?

Possibly, but I don't know yet. I'd like to see the REW data first, to see if there might be any reflections coming off those and doing strange things to your sound, and I'd also like to understand what they are doing to your bass.

By the way, I should warn you that the first test you do with REW in the empty room, will look pretty terrible, and it will sound pretty terrible in there as well! That's the point. I want to see the raw room behavior, all by itself, to understand exactly what it is doing. Based on that and the second test (after you install the initial treatment) we can figure out what additional treatment might be needed, if any.

7. How wide should the cloud be above my head?

At least 4', and maybe a bit more. If you really wanted to get fancy, you could build a proper hard-backed cloud for there, and hang it an an angle to further improve the acoustics. It's just a wooden frame with thick plywood, OSB, or MDF on top and OC-703 underneath, hung on chains (for safety, and also so you can adjust the angle), and tilted down at the front. It helps with reflections, and possibly also with modal issues in the vertical axis.

Also, the pad directly behind my speakers will run from bass trap to bass trap because

The probably don't need to be that big. Your room is 124 inches wide. You'll have 76 inches between the bass traps. Your speakers will be 54 inches apart, located 34 inches from the side walls: In other words, the center of the speaker will be 10" from the edge of the bass trap. So on that side of the speaker, the front absorber will go right up to the bass trap, and on the other side it can extend 20 inches towards the center of the room (it will be 30" wide). So on each side we'll have 24" (bass trap) + 30" = 54". So there will be a gap in the middle of about 14" between the panel on the left and the panel on the right.

The same with the height: You probably don't need to go all the way up to the beveled cornice. As long as you are getting coverage to about 18" above the top of the speaker, you should be OK.

I don't want to cover the entire front wall with absorption: you do need a bit of life up there.

You mentioned nothing about having not having a rear wall so I am assuming this isn't too big of a problem as well.

It has pros and cons! On the positive side, you won't have any rear-wall SBIR problem, which is normally a big issue in small control rooms. That's a major plus. Also, you'll have no modal problems on the longitudinal axis. On the negative side, you won't have any diffuse reverberant field coming from the rear wall, which is a good thing, and also there will be two different decay rates: one associated with the "alcove" of the room itself, and a much longer one associated with the room beyond. So it's a mixed bag: And since there's no way to build a wall there, we'll just have to live with it. "It is what it is!".

Lastly, any suggestions on what I should use on the frames for my panels and bass traps? 2 x 4's or 1 x 4's? I am thinking I will be wrapping them in burlap as well.

1x6's would be better, so you can get in the full 4" thickness of the 703. 1x4 is only 3 1/2 wide, so it would be fine for 2" 703, but not for 4" 703. A 1x6 is 5 1/2" wide, so that gives you room to set the 703 a bit back from the fabric covering, and also leave an air gap behind it, which is good.

If you want to increase absorption even more, for much better effect, then cut large slots in the side frames. Like this:
Or like this, with the fabric completely covering the unit:
Here's a close-up view with the fabric made invisible, showing the slots and also how you use thin plastic mesh to keep the 703 in place, and prevent it from pressing up against the fabric from the inside:


With the plastic mesh made invisible, to see the 703:


And finally with the OC-703 also invisible, so you an see how a strip of black fabric is glued over the slots on the inside, to stop light getting through. Otherwise you'll be able to see the ugly interior through the outer fabric:

I am thinking I will be wrapping them in burlap as well.

Burlap would be fine, or any other "breathable" fabric. "Breathable" means that you can breath through it: if you put a piece over your mouth and noise,m you should be able to breath through it without difficulty: Some fabric have a very tight weave, or some type of coating on the fibers that stops or restricts air moving through. You don't want that type of fabric. It must be breathable.

- Stuart -

Okay so I have finally finished my treatment and am getting around to testing. However for the life of me I could not figure how to properly set up REW, but I think I might have done it correctly now.

Unfortunately I do not have any dry tests of the room because it took a very long time for my SPL meter to come in the mail and my father wanted to finish the project asap.

These are the sizes I made all my panels and some pictures of what I am working with now.

Cloud = 60" x 42" 5 1/2" - 4" thick of OC 703
Front walls = 55" x 24" x 5 1/2" - 4" thick of OC 703
Super Chunks = 24" x 24" x 34" x 78" - Filled to the brim with OC 703
Side Panels (I went a little bigger than you suggested hope this isn't causing more problems than it is fixing...) 36" x 48" x 5 1/2" - 4" thick of OC 703

Album of room
https://imgur.com/a/aB0UQ

As for the calibration of my speakers and REW here is what I did.

I started by running a loopback through my interface using a 1/4" cable from the input to the output (Either the left or right speaker output.) I went to preferences and changed the sweep level to -20dB (I think this is what you meant by "setting the gain structure set correctly all across the system at -20dBFS (and/or 0dBu)") and adjusted my input gain until it read -20dB on both the out and in meters, then created a CAL.

Next, I set up my SPL meter on a tripod and located it as close as possible to the center of my head where I mix. I started by turning off both speakers and using the hand held SPL meter (mine cannot hook up to my interface, not sure if this is an issue.) to set the sub to 77dB give or take a few decimal points using the sub setting in check levels. Then I turned off the sub and set each individual speaker to 77dB one at a time using the check levels with the main speakers selected. I then checked all at the same time using check levels with the speaker setting selected and did get a reading between 85dB and 86dB, so I believe all is well there. If all of that sounded correct to you I believe I might be calibrated correctly.

Here are 7 tests after basic treatment. As I said at the beginning of the post, I don't have any valid tests of the room when it was completely empty. However, if it is necessary I can pull all the panels out (except for the super chunk as they are screwed directly into the walls) and take some more tests.

Sorry about any formatting issues I am very tired as a write this all up.

Thanks,
Steven

Edit : Again for some reason I couldn't upload my data file, here is a dropbox link with the measurements.
https://www.dropbox.com/s/a21h8v1ab4vzk ... .mdat?dl=0

Also I will be making my stands next, I have my sorbothane!

I could not figure how to properly set up REW, but I think I might have done it correctly now.

The data looks valid and makes sense, so it looks like you have the idea right: However, I don't get why the L-- and R-- curves match each other very closely, but the L-S and R_S are very different: L-S is about 6 dB higher! So there's still something wrong with the way you did those tests.

I went to preferences and changed the sweep level to -20dB (I think this is what you meant by "setting the gain structure set correctly all across the system at -20dBFS (and/or 0dBu)")

Nope! I meant that you have to go through the full process of setting your gain correctly on even single device in the signal chain, starting from the mic and all the way through to the speaker. When you provide a calibrated input to each device, you must set whatever controls are necessary on that device such that it sees the signal coming in at the correct level, and sends it out again at the correct level. That level will either be -20dBFS if the device is digital, or 0dBu if the device is analog. That's what the term "setting your gain structure" means. REW is just one of the devices in the chain, and it does need to be set correctly, but so does everything else.

If all of that sounded correct to you I believe I might be calibrated correctly.

Yep, that part is all correct. You did it right, and the fact that you got around 86 dB with all three running confirms it. But that does not explain why there's a 6 dB difference between L-S and R-S: Something changed after you calibrated, by the looks of it.

Also I will be making my stands next, I have my sorbothane!

Looking forward to seeing that!

- Stuart -