Home Mix Room Overhaul - DIY Panel Build - w/ REW Charts/3D Sketchup

#1

First off, hello to everyone and I hope you are well amidst the crazy year of 2020!

I was an active user on the John Sayers forum back in 2012 and received a ton of incredible help from Stuart (Soundman2020) regarding a studio build I was planning (link: http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=17481&sid=1ea662a881e1e1d32d0ddd5e6866ec4b). Unfotunately, due to funding and some other reasons, that studio never got built (and thanks to Stuart and some others the design was looking amazing by the end!). However, I've continued writing/recording/producing in my home ever since. I've been in many projects over the years from acoustic to psych rock. Currently, I'm doing much more on my own and without a band. Bandmates got married, landed 9-5's, etc etc you know the drill...

Fortunately, I teach lessons for a living and still get to work on music more than the average 29 year old (NOT 30 yet! :roll:

)

All that being said, I am finally taking the time to make my current mix room much better than it is! I've just lived with it over the years (with about 10 4" deep 2'x4' panels from ATS...see photos below). I've already bought most of the materials and started building some panels. I'm using a design by Jesco Lohan from over at http://www.acousticsinsider.com based on a budget friendly "sweet spot" acoustic panel where the idea is to get a more even absorption across the whole spectrum without completely breaking the bank (I am aware that it's not on the level of what a true ground up studio build could achieve but I'm hoping it will be MUCH better than what I'm currently working with)...here are the specs:

- 1x8 frames built at 2'x4'
- 6" insulation fill - I'm using rockwool AFB 2.5lbs/ft3 (two 3"depth panels stacked within the frame)
- 1x2 inner frame for fabric (I'll be using a premium tighter weave burlap)
- (ultimately, if mounted flush to a wall, this will leave about a half inch air gap within the panel in addition to the 6" insulation itself)

You can find a detailed blueprint of this panel here: https://www.coreybautistaaudio.com/diy-acoustic-panel-guide

I went this route because it seems more doable than trying to build any kind of framing within the room itself. However, I am a little more open to this moving forward...now that I've gotten some experience making a few of these panels. I had little to no wood working experience prior to this... :idea:

Here are the control room specs:

- 219 sq ft
- 2604 cu ft
- 15.33' Length (front to back) x 15.42' Width x 11.88' Height

Other notes:

- double sided fireplace (brick mantle) behind listening position (juts out into the room from floor to ceiling)
- open doorway (no door) to the back/left of listening position
- hardwood floors (heartwood pine)
- very small crawlspace underneath (assuming there is insulation beneath the flooring but not sure)
- the walls are mostly plaster with lathe (spelling??) since it was originally built back in the 40's
- storm windows on outside of regular window frame (so theirs a gap between two panes of glass...planning to at least fill the bottom half of these gaps with rockwool)

All in all it's a bit larger in volume than the average home based control room because of the tall ceilings...but this puts it real close to the dreaded CUBE dimensions! :ahh:

I'm hoping this won't be too much of a hinderance with getting some better performance out of my mix environment.

On a side note, you will notice in the sketchup drawings that the middle room is even bigger so it would make SENSE to move things into that space...however, it is right next to the kitchen and also the very center of the home. My girlfriend loves me...but it would make things very challenging from day to day. In the front room, I plan to eventually add a door to the doorway ( :yahoo:

) and seal off the fireplace so she can come in and out of the house through the other entrance without bothering me too much.

In addition to that, I'm very set on keeping the mix position in that general orientation. Moving it forward or backward and adjusting the speakers a bit is ok, but I've had this place in many setups over the years and this is BY FAR the most enjoyable and comfortable. It also just makes sense from a stereo perspective since every other option creates an even stranger L/R wall scenario (because of the fireplace)

Current plan for acoustic panels:

- Take down all 10 of the 2'x4' 4" ATS panels and move them into the middle jam/live room (needs some treatment anyways)
- Build about 24 6" 2'x4' panels in total
- 2 across each main corner starting a couple feet off the ground but only one in the upper back left corner due to open doorway (also willing to build additional framing to fill in like a superchunk behind if the REW results are lackluster)
- 1 on each side of front wall (to the left and right of window frame) behind speakers
- 2 on the side walls at first reflection points
- 2'x2' 6" panels to cover the bottom portion of each window (leaving the top portion of windows open because I just can't part with the natural light I'm sorry! )
- 2'x2' panels on each side of the open fireplace with even more insulation between (30" or so)
- Hang more panels on the back walls and potentially the brick fireplace mantle (though I will do that after some testing of everything else to see where it's at...I really love the look of it plus it already juts into the room quite a bit)
- hang 3 as a cloud above mix position
- hang some in the ceiling/wall corners at front and back of room

Budget/Other Info:

- $1200 - $2500 (MAX)
- I have already bought enough insulation and wood for what I laid out above. Still waiting on some fabric samples as the local stores were terribly pricey.
- I've also already started building the frames with a buddy (who is also do some treatment to his own space).
- After the fabric I will be in the $1200 range for everything including hardware.
- Willing to invest and add more treatment moving forward depending on the results...but really hoping this gets me much closer to a desirable mix environment.

I've attached REW and sketchup screenshots below! As well as a few actual photos of the mix room.

I've tried to be as thorough as possible with following Stuart's guidelines on the REW tests (used the recommended Presonus mic and a Stuart approved sound level meter) but as it was my first time, please let me know if I need to redo anything! I'm only somewhat aware of how to decipher all of the charts. I also captured some of them in smaller frequency intervals because they seemed too smushed to read otherwise...hope that's ok (I did the measurements from 10 to 22k though I swear!! :geek:

)

Really here to absorb the knowledge of this forum, document the progress of this project, and get help from anyone willing to offer their time! I really appreciate it in advance and hope to make this a success!

Cheers!
Trevor

#2

Hi Trevor, and a BIG welcome to you!

So glad you found the forum, and signed up.

Wow! I figure it's been maybe 8 years or so since we last connected, when you were working on the design for the original studio. It's a pity that never happened, because the design was getting to be quite good! I think the studio would have worked out well.

Great first post, by the way! All of the details, concise and complete!

Anyway, getting down to the new place: I have downloaded the REW data, and I'll take a look at that, but just from the very low res graphs you posted, one thing is clear: you need truck loads of bass trapping in that room: Your decay times are around 450 to 500 ms by the looks of it (rough estimate: I'll get more accurate numbers after I see the REW data...), and should be around half that for a room that size: maybe around 250 ms.

One question: you did the REW tests with the treatment in place, right? In other words, the room was pretty much exactly the way it is in the photos when you did the REW test, with the panels on the walls?

So I'll take a look at that when I have a moment, and let you know what I think. But what I'm thinking right now is: Bass trapping!

- Stuart -

#3

OK, I took a real quick look at your data, Trevor, and the good news is that it is valid! You did the tests correctly, and you calibrated correctly too.

The bad news is that it isn't pretty. On the other hand, it's not terrible either! That high ceiling and the reasonably large dimensions are very much on your side. I'm not sure if you found it yet, but there's a document with the cryptic title "ITU-R BS.1116-3" that lays out the specs for a "critical listening room", and those are often used as the goal for studios. It's hard to achieve those specs, but the idea is to get as close as you can. One of the basic parameters is that the floor area should be at least 20m2, which works out to roughly 215 ft2... and you are just about that! You can find that document here, in the reference library: Useful reference documents for designing and building a studio You can skip to chapters 7 and 8, since the first few are not relevant to studios (the document was originally about methods for doing listening tests on audio systems, and has sections on the how to design those experiments, selecting the people to do the listening, selecting the music to use for the tests, statistical analysis of the results, etc. Not important for control room design!) But chapters 7 and 8 have all the detailed specs for the speakers and the room... you might find that interesting.

My guess about the decay times was pretty close: the T30 time is around 450 ms for each speaker individually, and 437 with both. A pretty good guesstimate!

I'll do a more detailed analysis of the data when I have a chance...

- Stuart -

#4

Stuart!!

Thanks for the SUPER quick reply. Really stoked to reconnect and undergo a more manageable project this time around. I do wish the first studio could have seen the light of day though. It would have been next level compared to this!

Great first post, by the way! All of the details, concise and complete!

Thanks! I tried my best lol. I'm going to edit my first post to include listening position measurements. I forgot to add those in there.

One question: you did the REW tests with the treatment in place, right? In other words, the room was pretty much exactly the way it is in the photos when you did the REW test, with the panels on the walls?

Yep! The test was done exactly like you see in the photos. Those are just 4" deep 2'x4' panels made by ATS acoustics (10 of them total). And CLEARLY they are not doing nearly enough for a room that size...which is what I figured. :roll:

OK, I took a real quick look at your data, Trevor, and the good news is that it is valid! You did the tests correctly, and you calibrated correctly too.

You have no idea how relieved I am. :yahoo:

haha

The bad news is that it isn't pretty. On the other hand, it's not terrible either! That high ceiling and the reasonably large dimensions are very much on your side.

I figured it would be pretty rough.

It's hard to achieve those specs, but the idea is to get as close as you can. One of the basic parameters is that the floor area should be at least 20m2, which works out to roughly 215 ft2... and you are just about that!

At least I hit one of the marks! :lol:

And I just went through and read both of those chapters you recommended. It's written in quite the cryptic language but I think I absorbed a good portion of it lol.

one thing is clear: you need truck loads of bass trapping in that room: Your decay times are around 450 to 500 ms by the looks of it

I figured this would be the case! And now I'm hoping I didn't jump the gun by starting to build the panels I described in my original post. :shock:

I will try to update the sketchup model with panels placed where I am envisioning them and then see what everyones thoughts are. Maybe I should be building additional framing to house more insulation behind the panels somehow?!

Questions:

1. If you were to add the ideal absorption/bass trapping around a room like this...what would it look like/how would you go about it? I'm guessing a pro carpenter would be building framing directly onto the walls, then filling with a ton of insulation, and finally wrapping with fabric and touching up with an outer trim. Which leads to my next question...

2. How do you feel about the 6" panels I've started building as a "budget friendly" alternative? With the initial plan of placing them in wall/ceiling corners, front and back walls, and as a cloud? Maybe even putting a spacer behind any that are not in corners for an additional few inches of air gap?

3. Could the long decay time be caused partly by sound going through the open doorway and double sided fireplace and then hitting even further walls in other rooms before bouncing back? Do you recommend hanging a door and sealing off the fireplace sooner than later?

Thanks again! Really appreciate the help.
Trevor

#5

Ok, so as I await some replies, here is an initial idea I have for the panels I'm currently building for my mix room! :idea:

I've attached 2 photos from Sketchup showing the panels (all true to the dimensions being built) going long ways across the corners and attached up the wall (not sure I've ever seen it done like this but I'll explain my "reasoning" below). The back left corner only has 2 due to the doorway. I've then placed a few others around the room. I did not draw in the cloud panels but I'd have enough material left for 3 of those if I used exactly the amount shown (including the 4 square window panels and double sided fireplace panels).

The reason I went for wider corner treatment is based on Stuart's initial REW analysis that this room is going to need A LOT of bass trapping. I was initially planning to do just a couple long ways on each corner...but I'm thinking, if I go this route maybe I could get more bang for my buck in the low end (especially if I invest in some additional insulation to fill the air gap in the corners even more). I realize this will take some additional carpentry but I'm willing to learn what I need to to make it work.

There are a couple challenges I see right out of the gate:

1. It will be tough/awkward to build custom panels to fill the random gaps (between the panels shown) created on the front and right walls at first reflection points. The windows make this challenging -- as well as the wide corners eating into that front wall space. The left wall reflection point should be easy though as there is more space (hence why I've already added a panel there).

2. I will run out of panels and need to build more if there is need for additional coverage on walls or ceiling corners (not really a flaw but just an observation)...I'm just making a WILD guess that the material I've bought so far (28 panels worth) won't be enough in the end. :shock:

What's everyone's thoughts/opinions on this first layout idea? A good direction to go in as a starting point for the room? What am I missing?

Cheers!
Trevor

#6

Ok so here is a potential workaround for the front wall behind the speakers in that gap between the window panels and corner panels.

I would just have to make the panels slightly thinner but it would be easy to do by flipping the way I attach the boards and then it would fit.

I'm also thinking maybe it would be best to do one long panel across both lower windows? It would jut out more but also leave a beneficial air gap behind. What do you all think?

#7

Annnnnnd one more set of photos for ya! Haha the can has been opened... :ugeek:

So here is the front wall with two long panels on the windows instead of the smaller squares. Still not enough to create no gap at all but better I think? Plus this leaves a little more air behind and goes flush with the other two on either side of the windows. I also added more panels at the left and right reflection points.

And then here is the back wall with the three panels scooted out from the center wall above the fireplace creating a 5.64" air gap. I could even stuff some more insulation behind these like with the corner traps to create even more low end absorption. Again, I'd have to build some additional custom framing on the sides and whatnot but I'm willing to make it happen if it would help.

Does anyone think it's a good idea to put those other three panels (slightly see through in the photo) on the wall by the doorway since I can't continue the corner all the way down? Would that help keep the absorption a little more symmetrical or is it unnecessary?

Also, I think one post may have gotten lost in the uploading process but basically, since Stuart said right out of the gates that this room would likely need A TON OF BASS TRAPPING, I chose to immediately flip all the corner panels horizontally and probably stuff more insulation behind them on shelves or whatever rather than just an air gap. Wondering if this would help with the low end considerably more than just going vertical across the corners with an air gap and no fill? Not too worried about losing floorspace in here and I'm prepared to invest a little more than the $1200 I've got in this for the ~28 panels.

Let me know your thoughts!

Cheers
Trevor

#8

Last one for the night I think! :horse:

Just wanted to give everyone an idea of my "plan" for the cloud. I just roughly drew this in. I've seen Stuart recommend some people go with a hard back cloud at a steep angle to send some frequencies toward the back wall. Wasn't sure if that would be applicable to my room.

Let me know your suggestions for cloud placement in this size room!

Thanks again to anyone willing to chime in. It's much appreciated.

Trevor

#9

Birdseye view... to help see the whole vision so far. Please feel free to tear this apart! :lol:

I'm just throwing it all out there as a starting point.

#10

shybird wrote:1. If you were to add the ideal absorption/bass trapping around a room like this...what would it look like/how would you go about it? I'm guessing a pro carpenter would be building framing directly onto the walls, then filling with a ton of insulation, and finally wrapping with fabric and touching up with an outer trim. Which leads to my next question...

As a starting point, I'd be going for maximum effect of absorption with as small a surface area facing into the room as possible. Too much broadband absorption will deaden the high frequencies far quicker than the low.

Corners are very effective for these, so I think your plan of turning them on their side to make a larger span is good. I definitely would not build these as individual panels though. It would be far quicker, cheaper and effective to build them superchunk style. This is well within the remit of the amateur carpenter.

After building these I'd also put some in the ceiling / wall corners if required.

shybird wrote:2. How do you feel about the 6" panels I've started building as a "budget friendly" alternative? With the initial plan of placing them in wall/ceiling corners, front and back walls, and as a cloud? Maybe even putting a spacer behind any that are not in corners for an additional few inches of air gap?

My inclination would be for the deeper insulation that a superchunk would provide, then see what is required for the walls not in corners.

shybird wrote:3. Could the long decay time be caused partly by sound going through the open doorway and double sided fireplace and then hitting even further walls in other rooms before bouncing back? Do you recommend hanging a door and sealing off the fireplace sooner than later?

The general advice is to finish all your sound isolation before refining the acoustic properties within the room. It's good advice - the open doorway will be having a significant - some might say huge - effect on your results. Even with the door from my place into the stairwell open a little bit you can totally hear the reverb from the stairwell. So yes, get a door installed before you do anything else, as what you are currently measuring is not what you'll eventually be treating.

Presumably the fireplace will be having a similar effect. However, I do know that you have to exercise caution sealing these off as damp can result if not done properly. I'd consult someone with appropriate expertise of doing this to properties constructed at the period yours was before attempting modifications.

Cheers,
Jennifer

#11

Hi Jennifer thanks for the detailed reply! Very helpful. I've drawn up a new model with potential "superchunks" in the corners (see images below). These are basically double the width of what I see most people doing as superchunks. I figure with this size room they will be more effective at this size...

endorka wrote:Source of the post Corners are very effective for these, so I think your plan of turning them on their side to make a larger span is good. I definitely would not build these as individual panels though. It would be far quicker, cheaper and effective to build them superchunk style. This is well within the remit of the amateur carpenter.

This makes sense! I just wish I had consulted the forum first. :cry:

I went the panel route so that nothing was too permanent (even though I don't rent) and because I thought it would be the easiest... :roll:

So if I end up building these super chunks, I'm going to have quite a few extra panels that I would need to sell. I've already built the main 24 frames for these...

However, I'm willing to consider going this route if needed. The flushness of the superchunks is nice but I don't mind the look of the panels across the corners either. I think I'd be aesthetically happy either way.

After building these I'd also put some in the ceiling / wall corners if required.

More superchunks or panels across these areas?

My inclination would be for the deeper insulation that a superchunk would provide, then see what is required for the walls not in corners.

If I did go the panel route and filled in the gap with some additional insulation, that would be similar to a superchunk correct?...just a different build structure?

The general advice is to finish all your sound isolation before refining the acoustic properties within the room. It's good advice - the open doorway will be having a significant - some might say huge - effect on your results.

This makes total sense as well! I figured that open doorway needed to be addressed sooner than later. It is an awkward/big frame though so I'm not sure where I will find one easily. Might have to custom making something. :shock:

Presumably the fireplace will be having a similar effect. However, I do know that you have to exercise caution sealing these off as damp can result if not done properly.

I know someone who builds/renovates homes in the area (same guy who renovated this place) so I will contact him to ask for guidance. Hopefully it's something I can do myself without having to pay for additional labor.

Thanks again for the help!
Trevor

#12

Actually, I didn't realize I'm actually short quite a few panels if I DON'T go the superchunk route. And if I do go the super chunk route I'd probably only have about 4-8 panels leftover. I could sell them or even utilize some of them as moveable gobos as needed. So I think I'm leaning toward the superchunks after all... :jammin:

#13

Also, it appears I need a door that is 3'x7'... this might be a more standard size than I thought. Going to do some research. Thanks again for the help!

#14

Would something like this work? It's 1.57" thick made of solid wood. I'm guessing it's not enough since that likely won't match the sound isolation of the walls. Could I just reinforce something of this price range with some dense material before hanging? Also assuming this could be made into a regular hinge door rather than sliding like shown.

https://www.overstock.com/Home-Garden/B ... wds=&rfmt=

Or am I going down the wrong path and should consider building my own?? :shock:

#15

shybird wrote:Source of the post Hi Jennifer thanks for the detailed reply! Very helpful. I've drawn up a new model with potential "superchunks" in the corners (see images below). These are basically double the width of what I see most people doing as superchunks. I figure with this size room they will be more effective at this size...

Looks good to me at the front. For the rear corners though, I'd tentatively design with the panels rather than superchunks, at least as a trial. Reason being the asymmetry at the rear of the room caused by the door being right in the corner. The panels will allow you to try out various schemes. I've personally observed sonic irregularities from asymmetrical bass trapping, so my first effort would be to straddle panels across the corner above the door, then mirror the same arrangement on the other side, and see if it is good enough. Maybe non corner straddling panels placed symmetrically on the door and mirrored on the other side would be sufficient in conjunction with other bass trapping on the rear wall?

endorka wrote:Source of the post Corners are very effective for these, so I think your plan of turning them on their side to make a larger span is good. I definitely would not build these as individual panels though. It would be far quicker, cheaper and effective to build them superchunk style. This is well within the remit of the amateur carpenter.

After building these I'd also put some in the ceiling / wall corners if required.

More superchunks or panels across these areas?

Since you have an abundance, the panels would be ideal. They'll also allow some trial and error testing.

If I did go the panel route and filled in the gap with some additional insulation, that would be similar to a superchunk correct?...just a different build structure?

Pretty much. There are various approaches to filling superchunks with insulation. For superchunks of these size I'd be inclined to face them with the rigid rockwool and fill behind with far less dense (and cheaper) fluffy insulation.

For the door, do you have Rod Gervais' book? He has excellent plans for augmenting a standard solid door. Stuart has written on this site on the subject too.

You're spot on about not worrying about having too many panels by the way. I have two slightly smaller rooms than yours, and I initially built something like 40 panels. Some now employed in the second room, on the stairwell landing, as gobos, you name it. I'm still building them as we speak :-)

Cheers,
Jennifer

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