Old Studio Rehab.

[BackEastDon]

20 years ago I built a small home studio in my attic. About 10 years ago, with kids in college, I sold off a bunch the gear worth money and took a job with an insane amount of travel. Last year I started dusting everything off, bought a new Mac and some gear and have been figuring it out all over again.

I live out in the country, no issues with noise abatement. The studio control room is 12.5 x 18 ft with the angled ceilings at both ends. I built the desk up tight the wall but pretty deep. Used a lot of mass, ton of insulation and cases of silicone. Its a quiet and in the right places, a good sounding room. Room currently has about 200 sq ft of fiberglass panels. Still with desk placement, I miscalculated the sweet spot and found myself alway rolling my chair back a bit.

I spent the morning searching to see if there was much to be found but came up with little. Though John's old post with the small studio design has a detail that corresponds to one of the ideas I have and subsequently part of the questions I have. The small studio design has soffit mounted speakers which seems kind of unusual for a small space. My main curiosity starts with how well does this work in a small space? What are the monitor choice considerations? How far back works for this sort of near midfield set up?

I'm posting a picture of the current desk and a quick sketchup capture image I made this afternoon. I resized both as suggested in one of the posts I read. I'm looking to move the console to the side window for tracking with rack space underneath and use a smaller desk further back but still keeping listening position in that 38% range. Aiming the monitors just slightly behind my head would give me a distance of 90 inches to the front wall strait ahead. Hope this give you enough info. Crossing my fingers I enclosed the images correctly.
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[gullfo]

it should work nicely since it will reshape the room ratios and provide a space for the LF trapping you need. the back slope ceiling will need some additional treatment, and you could also "soffit" the back wall as well to provide for more LF trapping.

[BackEastDon]

it should work nicely since it will reshape the room ratios and provide a space for the LF trapping you need. the back slope ceiling will need some additional treatment, and you could also "soffit" the back wall as well to provide for more LF trapping.

Thanks for the input. With the angled ceiling, it just seems like I am building a horn lens out of the front of the room.

The goal is to redo the rooms sound treatment overall. Back wall is fairly well treated already though this room is a sort of reverse live end, dead end due to the desk being up against the wall. I'm just regretting not putting up 2inch panels instead of 1inch fiberglass sandwiched with 1/2 inch soundstop fiberboard. I had a lot of leftover fiberglass so I bundled 6 together and wrapped them up in burlap and placed them each of the back corners. It is time to do something a bit more elegant. When the futon was in the back of the room and the sub was in the right place, the bass curve wasn't too far off.

With ever wider computer monitors, it has really wrecked havoc with the placement of everything. Sub is currently in the wrong place but I got tired of hitting my knee against it. Moving the desk will solve some some issues and likely create new ones but hoping it ends up better overall.

Plan is to continue to use my ancient little KRK's up close and begin to shop for larger monitors. This is why I asked about what considerations need to be made when choosing monitors for soffit mount ie front ports vs rear?. 9ft triangle is about what I am looking at. Option B would be to place the bigger monitors on stands and just build big wedge absorption traps for both front and back.

[BackEastDon]

As to bass in the room, here is a graph from 40-1khz of the average of 6 measurements within box area of old and new mix position. My little 4" KRK don't do low end so I grabbed an old pair of KRK ST6's from my video editing setup. These were placed about where I'd mount them with or without soffit. Keep in mind these are hyped at the bottom end. As I indicated, I've not moved the sub back to a better position so I'll work on that once I have the new desk moved up so this is without sub. Then I can see how monitor placement affects the response to see if I can't tweak placement a bit in this new configuration.

ST6 Average.jpg

[BackEastDon]

Took a little time to work on this.

After a lot of searching, reading and thinking (took a good bit of drubbing to), soffits are not making sense. It seemed like an interesting idea but probably one I'd rather not risk the time. money and possibility of getting it wrong.

I've torn out the old desk and built a new desk with a new rack to hold the console. The new furniture gives me more flexibility as to movement and monitor position either forward or back depending on where I end up with treatment. If you look at the sketchup above you'll see the soffit detail. Remove that angle and replace it with a 4ft W x 4ft H x 2ft deep absorber filled with low density fiberglass. I can't go completely across because I have two quad outlets but can treat the area above the outlet, probably go a bit less deep and put my amp rack there.

Rear of room with get the same except completely across the entire back. I'm losing guitar case storage. Think I'll survive.

As you can see in the picture, I'll need to build a window plug and I also have another window to my left. I previously built a wood extension for the outside window case and have a plug made with 2 inch 6lb rigid with a compress fiberboard backer that snugly fits. I'll probably extend this once I figure out how far out to come with the side treatment. Probably 6 inch Safe n Sound framed around the entire front to just behind the window which would leave a box cut out for the two plugs.

Still working out the physical design of the cloud but the flat part of the ceiling only covers 12.5ft x 8ft and then I have those two angled ceilings. From the listening position the front is 4ft away and back 8ft. Don't want the room entirely dead. Got a ways to go to figure out calculating slats and how they would affect the absorbers. (working on it).

The angled ceiling and the floor are all that remain to be decided on. Carpet, stay or goes? What to do with the two angled surface areas?

Studio_09.jpg

[gullfo]

you can think of the ceiling peak as a corner - span that with as deep as you can spare with a "corner trap" as the first part of adding a cloud system to the ceiling.

[BackEastDon]

you can think of the ceiling peak as a corner - span that with as deep as you can spare with a "corner trap" as the first part of adding a cloud system to the ceiling.

Thanks,

I was already thinking of extending up from the 4x4ft floor traps in front and back with a wedge of sorts which would also raise absorption up to 66 inches. That would take care of the lower transition. wall "corner" and the wall would look a bit taller that way. I hadn't thought of the tops of the ceiling. I'll have to figure out some sort of framing detail and attachment or could just angle the front and rear cloud so it extends out.

Based on early measurements and the room calculators (they track to an extent) I am starting to see trends in peaks at various speaker and mic placement. The consistent 90hz spike related to 12.5ft width is below Schroeder and still working on educating myself on how best to treat a pressure region below Schroeder.

Thinking at this point of building the front and rear traps first even if temporarily framed and measuring bass response before moving on to the side treatment. The way it measures now, I am not certain 6 inches along the sides will be enough but don't have enough knowledge and experience to predict.

[gullfo]

the advantage of the ceiling is that sound is 3D and you preserve floor space. for treating pressure you need to build pressure based traps, not porous (flow) absorbers.

[DanDan]

There are Absorption Data for 6" of various fibres at bobgolds.com Given figures like 1.3 in the 125 or 100Hz octave it seems your 90Hz should be amenable to simple fibre treatment.
Area is a a factor though.

[BackEastDon]

There are Absorption Data for 6" of various fibres at bobgolds.com Given figures like 1.3 in the 125 or 100Hz octave it seems your 90Hz should be amenable to simple fibre treatment.
Area is a a factor though.

I had initially looked through the Bob Gold site but there are but few 6 inch references and there is also the issue of trying to match what can be obtained relatively easily.

I instead started looking at GFR data and plugging that into the porous absorber calculator which I've have been advised isn't always accurate of real world results. The two products I compared that I can just pickup locally is OC EchoTouch R19 with a GFR #2900 and Rockwool Safe n Sound #10000. At least in the calculator, it seems to come up short.

Should I instead simply rely on the NRC specs when I can get those? I do get that the calculators are normal incidence (slowly starting to understand some of this). At least at a basic level.

I also have another question if I could be permitted two. My current plan is instead of deep wedge corner traps, build instead 4ft x 4ft x2ft box traps for each of the 4 corners as I can only extend up 4 ft before the ceiling transitions. Side wall treatment will go all the way forward into those angled corners. My goal is to get enough treatment to offset moving my desk and monitors out from the front walls. Larger bass traps means I cannot move the monitors back against the wall. Just want to know if I am on the right track with my thinking. Will enough absorption against both back and front offset the rear monitor reflections? I'm talking 2ft of pink fluffy at both ends.

[BackEastDon]

the advantage of the ceiling is that sound is 3D and you preserve floor space. for treating pressure you need to build pressure based traps, not porous (flow) absorbers.

And somehow I completely missed this post.

I've been reading a lot on both limp membrane and panel calculations including isothermal variants. I've entered the formula into a spreadsheet with each (coefficient?) so I can enter mass per sqft and depth for each type. Slowly identifying the material available and plugging those numbers in. Question becomes don't side wall modes need treatment mounted on those side walls? Then how to balance the need for broadband absorption and more targeted absorption in the limited side areas especially between mix position?

Then how much do I need to be effective? Minimum size I can build them in blocks? (for lack of a better term). Like if I wanted broadband at ear level, can these go below and above in 2ft x 4ft units mounted laterally. For clarity, isothermal membrane nearer the floor sideways with a broadband flow absorber above at ear level and another membrane trap above.

[DanDan]

Should I instead simply rely on the NRC specs when I can get those? I do get that the calculators are normal incidence (slowly starting to understand some of this). At least at a basic level.

Try Random incidence or even better, 65 degrees, it's more encouraging and gets somewhere closer to the Lab tests.

I am not sure if I follow your second question, but I will take a chance.
Big deep corner absorbers are always welcome.
Absorption between Speaker and Front Wall quite often causes a bigger problem than it attempts to solve.

[BackEastDon]

Should I instead simply rely on the NRC specs when I can get those? I do get that the calculators are normal incidence (slowly starting to understand some of this). At least at a basic level.

Try Random incidence or even better, 65 degrees, it's more encouraging and gets somewhere closer to the Lab tests.

I am not sure if I follow your second question, but I will take a chance.
Big deep corner absorbers are always welcome.
Absorption between Speaker and Front Wall quite often causes a bigger problem than it attempts to solve.

Perhaps more simply. Triangle shaped wedge in the corner vs big large square box absorber. Wedge, I could at least get a mid-nearfield speaker close to the wall. Big box absorber, I am out at the desk with both monitor pairs. It's one approach vs the other. I guess alternately, wedges up front and big boxes in back.

At the new desk position, bass response is not great. I lack the experience and intuition to know if the bigger bass absorbers will do enough to improve response. I have an old pair of 4 inch KRK that I've used forever up close. Low end is not a thing with these but with the desk away from the wall, well just not the same. Further back and I'm at mid point, further front, I might as well have stayed against the wall.

[gullfo]

it's a reasonable approach - front corners using wedges, large boxes in the back, big boxes on the main axial points, and smaller rectangular units on side walls for reflection control, and some big units overhead for clouds.

[BackEastDon]

it's a reasonable approach - front corners using wedges, large boxes in the back, big boxes on the main axial points, and smaller rectangular units on side walls for reflection control, and some big units overhead for clouds.

I've been spending time learning some of the "how to's" with treatment design so that I'd have at least a couple tools under my belt in re-orienting this room. I've also been a bit stuck in analysis paralysis. I read one of your posts that convinced me to just get it moving and try to do this a bit more progressively. You had said that you have never seen a room not improved by adding bass traps.

So I'll be heading out in the next couple days to pick up some R38 fiberglass and am going to just mock up the 4 corners and then measure while I adjust placement of the desk and monitors. Something is telling me I'll need to move the desk orientation forward but I feel I'll benefit from getting something in the corners first, then adjust.