John Sayers' Recording Studio Design Forum Archive

For Father's Day, I bought myself a damned near mint condition 1988 Delta UniSaw with a bunch of accessories.

Wow! Nice! As in REALLY nice! You certainly must really appreciate your fathering skills, to deserve a gift like that!

- Stuart -

Dang, i bought myself wood putty.

Dang, i bought myself wood putty.

Equally as cool and necessary

Greg

I thought I'd give you guys an update. I finally found some time to start my soffit design. It's far from done but here's the start: - I've blocked out the speaker mounting itself as it is closely based on Stuart's proprietary design and out of respect for him, I won't share it.
- I looked through old and new speakers to see which ones I could see myself using in the future and found maximum width, height and depth measurements. Then based off of the acoustic axis I luckily only had to adjust the lowest platform supports. This would allow me to mount some tall 3 way speakers like the Focal Trio6 BE, Genelec 1238A, or the Neumann KH 420. Now, I'm not sure if this is a good thing or bad thing, but my wooden soffit face would have to go all the way down there. It would leave only a small absorption panel for the reflections. I'm only really contemplating this because I don't know if I will EVER get tall speakers like those. Here, you can see how low the speaker bottoms will be in order to have the acoustic axis at the correct height! - The support platforms will be a weird shape, so I decided to split it in half (you can see the cut line in the middle of it) so that I will be able to install one half at a time.
- Against Stuarts recommendation (only because I physically can't pull it off, even though his idea is brilliant), I decided to make my speaker mounting module have a single flat 1" MDF sheet that would literally just slide in on top of the support platform and using T-Nuts and ready rod, it would bolt down.
- If I change the speaker models, I will have to add new platform support 2x4's to the framing on which the support platform would sit. Really though, this isn't too big of a job.
- The front mass will consist of 1" OSB or MDF, then 1/8" of steel, then 1" of nice looking hard wood or 3/4" of MDF and a 1/4" veneer.
- I still need to sort out hangers and where I will have a ventilation port. Unfortunately, my HVAC duct work is on the sides of the room so I won't have my return ducts sucking up heat directly above the speakers.

In other news, I'm continually checking Kijiji for a used 8" jointer. Nothing good as popped up yet for a decent price. I'm really going to need one to build nice treatment though!

Greg

- I've blocked out the speaker mounting itself as it is closely based on Stuart's proprietary design and out of respect for him, I won't share it.

Thanks! Appreciated.

like the Focal Trio6 BE, Genelec 1238A, or the Neumann KH 420.

Those are all very nice speakers. Frank is using the Trio in his place (I'm sure you've seen the thread! ) so you can get an idea of how those can perform. I have no personal experience with the 1238A, so I can't comment on it, but I did use KH420's for a design I did for the Netherlands a few years ago, and I can recommend those too.

Not sure if you are actually thinking of going with any of those, but that's my US$ 0.02!

based off of the acoustic axis ... soffit face would have to go all the way down there. It would leave only a small absorption panel for the reflections.

For large speakers like those, with very smooth response in the vertical axis, you could probably raise the acoustic axis a little if you needed to. Maybe an inch or two. Assuming you don't have the mix position too close to the speakers, you would still have your head very much in the clean, clear, smooth, even area, even if you are a bit "off-axis". You could easily set them up so your head is maybe 5°, or maybe even up to 10°, below the true acoustic axis, and you'd hear no difference at all. For smaller speakers, the vertical dispersion often isn't that good, so it's important to be on-axis, but larger speakers (especially great one like these three) often are better in that aspect.

- The support platforms will be a weird shape, so I decided to split it in half (you can see the cut line in the middle of it) so that I will be able to install one half at a time.

Yup. That's what I often do. Also, if you make it from two layers, you can split each layer in a different place, so the joints don't line up, then glue-and-screw to make a nice solid, firm, rigid base.

- The front mass will consist of 1" OSB or MDF, then 1/8" of steel, then 1" of nice looking hard wood or 3/4" of MDF and a 1/4" veneer.

Nice! That's going to be nice and heavy. You'll need a couple of people to lift that into place, and some substantial fasteners to keep it there. Work safely! You don't want that lot falling on your toes....

You might want to consider beefing up your soffit framing a bit too.

But over all, it looks good!

- Stuart -

Stuart, thank you for the encouragement. Whenever I get your approval, I know things are going to be alright!

Two questions for you:

- Would you recommend using Green Glue between the beef up layers (wood, steel, wood)?

- I'm not sure how far below the speaker bottom I should be aiming to have the absorption panel. I've seen a lot of designs (by guys like John) where it is only a few inches. I'm just quite concerned with the reflective surface causing havoc. Any advice on this would be appreciated.

I'll try and get more done on the soffit design here, but I really have to concentrate on redesigning my entire HVAC system

Greg

- Would you recommend using Green Glue between the beef up layers (wood, steel, wood)?

You could, I guess, but I'm not sure how well GG will work with steel. Steel is pretty rigid, and the point of GG is to mostly to damp bending waves, which you won't get much of if the panels are very rigid. It might still be worthwhile, since your steel is "only" 1/8, but I'm really not sure. Talk to the folks at GG, and see if they would recommend it for this application.

- I'm not sure how far below the speaker bottom I should be aiming to have the absorption panel. I've seen a lot of designs (by guys like John) where it is only a few inches. I'm just quite concerned with the reflective surface causing havoc. Any advice on this would be appreciated.

Ideally, start the absorber box at desk surface height, or a little below. But for very large speakers, that isn't possible, so just get it as close as you can to that. The real purpose of that device is to deal with any high and mid range reflections coming off the back of the desk or console, so another option is to design your desk to minimize reflections, or to redirect them lower down, where they will hit the absorber. So angle any rear faces on your desk, or build angled "shields" on there (eg, if you have a large format console with a straight-up rear panel or dog box), to reflect more downwards. You only need a small angle, probably: you don't want to be sending stuff to the floor, where it could reflect back at places you didn't want it to go. If that rear side of the desk/console is not going to be visible, you could even put some absorption on that too. Another option, if you are not using a large console, is to make the desk minimal: build it so that it does not offer much surface area at all in the speaker direction, to minimize reflections. Use mostly rounded surfaces, rather than flat surfaces for the structure.

I'll try and get more done on the soffit design here, but I really have to concentrate on redesigning my entire HVAC system

Wrong! You have to concentrate on EVERYTHING! All at once.... While you juggle a thousand and sixty three parameters at all once, and keep mental track of every single one, and how it affects each of the other thousand and sixty two parameters, in all possible combinations. (Think of Carl Sagan: "Billions and billions of stars...")

- Stuart -

So, if some of you don't know, I joined this forum around Christmas. I had done a lot of research online and like other new forum members, I had soaked up a bunch of wrong information. That, or maybe just a quote here and there that was correct, but was left with too many unanswered questions. I posted a few questions on here just like everyone else does and Stuart let me know that I was in over my head with unrealistic timelines. Within a few days, I realized that I could use the search feature to answer my questions. As you all know, once your search results pop up, you end up reading 15 page threads that lead to more questions and more searches. The questions keep coming up and luckily, with some pen, paper, an organized folder system on my computer and saving a ton of pictures, I have a lot of answers. Then, after downloading, and still making my way through the Master Handbook of Acoustics: http://www.roletech.net/books/HandbookAcoustics.pdf I'm still only scratching the surface of acoustics. However, compared to everyone else around my part of the world, it seems I have a GREAT grasp on it. I love this world of acoustics and plan to continue studying everyday. I enjoy helping people as it challenges me to solve new problems and therefore pushes me to keep learning.

This all leads me to let you guys know that thanks to this great forum and the wonderful Master Handbook of Acoustics, today I was hired as a consultant by an insurance company for the rebuild of a friends commercial recording studio that flooded a few months ago. The insurance company will only build it back to the way it was. If the owner wants to change or improve something, he has to pay for it. Apparently the project manager called around to all of the "acoustic companies" (I quoted them in disgust like that because all they do is sell the same old 2" thick 703 or equivalent panels with adhesive spray on them to hold on G of M fabric and they sell them in every scenario claiming that they will "sound proof" rooms). Every company told the project manager that they new a guy who knows a guy that knows this other guy who might know how to build a studio. My friend owns this flooded commercial studio that was built in 1983 and was built poorly. It is built as you'd expect if you were building a studio in 1983 and didn't have John Sayer's Recording Studio Design Forum at your disposal. No HVAC in the tracking rooms, no room in a room design. 8 Layers of drywall, maybe homasote, maybe press board, for sure a bunch of Asbestos crap, etc on an interleaved ceiling built of dimensional lumber 2x8's. Glass that feels like 1/8" plastic for control room windows. Here's a picture after the restoration company cut out the drywall everywhere that was ruined from a frozen water pipe above. Unfortunately the studio owner is concerned that the building may be torn down before he wants to move out due to it's age and the fact that the area is slowly getting a face lift. Therefore, he doesn't want to dump too much of his personal money into really fixing it up awesome. There is a store above him that strangely doesn't cause too too much noise above him even though the interleaved ceiling construction leads me to believe it is worse than he's letting on. Anyway, he is happy with the isolation he had and therefore I'm going to improve on what he had by making sure 703 is used everywhere and extreme amounts of sealing will happen. Instead of a mish mash of material is used on the ceiling, I'm going to have the company install 8 layers (because that's how many came down and that's what they're able to do on insurance $$$$) of 5/8" drywall, sealing every layer and applying Green Glue. I insisted that we get an engineers stamp for the joists and luckily there's room for probably 2x12 LVL stud if we need it to cover the span of 13' that it has to run. They will actually build a semi-decoupled wall in front of the control room wall (it will flank around all the corners) so it won't be great, but slightly better than it was. Also, on the studio owner's dime, we will install some silencer boxes and pipe in some fresh air into and stale air out of his tracking area. The CFM won't be enough for the room, but unless a MAJOR reno was done, it will be a million times better than what it has been since 1983. Imagine cutting albums all those years for 14 hour days with ZERO fresh air in the tracking room. He said they'd put 10 fans in there for lunch breaks but it wouldn't really help. Duh!

And in other news, I'm hired by 3 other home project studios in my area to help them either improve or build their spaces. One has been underway for a few months already. I'm so happy to be able to help people do things the correct way. So, thanks again to everyone who helps answer questions and contributes to this wonderful website.

Okay, time to work on some records then maybe work on my design some more!

Greg

One thing leads to another.

Control room size

Good things:
- I'm going to move the skinny part of my inner leaf (the front of my control room) over to where the frost wall is in the basement. I realized that there is no reason in losing that space.
- The LVL stud for my ceiling skeleton is long enough to accommodate this change (it gives me about an extra foot of width)
- This will help tremendously for achieving a larger RFZ sphere.

Bad things:
- This eats up room for HVAC silencer boxes and so now I'm redesigning all of those. Not going good, but it's going.

Noggins hurt my noggin

All bad things:
- 3 out of the 5 super heavy doors in my design are screwed for having reinforcing noggins. 2 of them will have jack posts (I have them drawn as round, but in reality they are square) and the 3rd one will be in the the corner up on a platform. I'll worry about that one when the live room design starts taking shape. See picture of the control room and ISO room issue here: These two will have the hinges on the crappy jack post side of the jamb

Question: How should I go about reinforcing these?

Thoughts I had:
- Steel square HSS tubing for a king stud (anchoring this to the concrete could be a pain as I don't really want a platform sticking out at the bottom due to me not having flooring - I am just applying epoxy to the concrete)

- It seems that strong wood flexes. It seems that hard wood is brittle. I was hoping to maybe just use some awesome wood that would be sturdy enough to not need the noggin situation.

- Cut a 4x4 to fit perfectly into the space between my outer king stud and the jack post then strap my king stud assembly to the jack post using some hanger strap.

- Maybe I'm over thinking the importance of the noggin reinforcement.

Greg

Gregwor wrote:Noggins hurt my noggin

All bad things:
- 3 out of the 5 super heavy doors in my design are screwed for having reinforcing noggins. 2 of them will have jack posts (I have them drawn as round, but in reality they are square) and the 3rd one will be in the the corner up on a platform. I'll worry about that one when the live room design starts taking shape. See picture of the control room and ISO room issue here:

Noggins Hurt My Noggin.jpg

These two will have the hinges on the crappy jack post side of the jamb

Question: How should I go about reinforcing these?

Thoughts I had:
- Steel square HSS tubing for a king stud (anchoring this to the concrete could be a pain as I don't really want a platform sticking out at the bottom due to me not having flooring - I am just applying epoxy to the concrete)

- It seems that strong wood flexes. It seems that hard wood is brittle. I was hoping to maybe just use some awesome wood that would be sturdy enough to not need the noggin situation.

- Cut a 4x4 to fit perfectly into the space between my outer king stud and the jack post then strap my king stud assembly to the jack post using some hanger strap.

- Maybe I'm over thinking the importance of the noggin reinforcement.

Greg

I'm struggling to visualise your door problem here. On the picture I can see simple openings for doors with timber lintels. That seems standard. But then you have what looks like metal columns in the wall. Do these have big hinges on and the whole wall opens?

I'm struggling to visualise your door problem here.

Do my arrows and text boxes help explain the issue better?

In other news, I'm re-designing the entire ISO room HVAC as after sitting down and doing the math, my idea to work around the mechanical contractors carnage won't work. Basically, I think I'm going to rotate the duct work 90 degrees. I will have to have both my supply and return inner leaf silencer boxes inside the room on the ceiling.

Pros:
- only two ceiling corners will be occupied by duct work instead of 3 in my initial design.
- less duct work = less cost
- no silencers above my ceiling joists means I will be able to maintain a good MSM gap

Cons:
- the large width of the silencer box hanging down right above the door in the room will make initial feelings entering the room claustrophobic.
- smaller room area.
- this new design will require me finding room outside of the room for outer leaf silencers.

I confirmed that I can in fact fit two of my inner and outer leaf silencers in the smaller space at the front of my control room. So, this means a drastic improvement in my control room footprint!

Once I get this HVAC sorted out, I'm going to call around and see what AHU will best suit my needs (and space). I really want to zone control my ISO room and control room.
I was looking into this one:

LG AHU

Concerns with it:
- Will the fan in it be able to handle the static pressure of the system? (I can't calculate that until I finish the duct work and silencer box design)
- It only has low, medium, and high settings. How will this fair with zoning and CFM/air velocity!?!?!?! I just imagine the electronic damper closing off my control room and it pounding on medium or high a ton of air into the ISO room with too much velocity. I'd prefer and variable speed unit for this reason alone.

Lastly, the home builder has told us that they expect possession date to be Sept 19th. So that's just 2 months away. The pressure is on for me to finish this basement design. I'll post more pics once I solidify more. Like Stuart said, it's a total juggling act in the design stage.

Greg

Okay, I'd like some other opinions for this as well please!

For my ISO room, as I stated in my previous post, I will have the inner leaf silencers inside the room. In this design, I will drop through my inside out ceiling into the silencers, and then they will attach to trunk with duct liner that hooks into my register plenums. Here it is: Concerns with this option #1:
- I will probably have to add a 4th baffle (acoustically this isn't bad, but it adds more cost and expense) in order to have the connection point to the trunk where it needs to be.
- I would like to move the silencer further into the room so that I have good tri-corner bass trapping, but then my silencer will probably be too long unless I go down to 2 baffles which isn't really an option in my opinion.

Now, the other option would be to extend my inner/outer leaf sleeve via normal duct and some flex duct along the length of the room and penetrate the inside out ceiling in the middle section of the room (where the register plenums are in the "1 Box Per" design picture above. From there, using Stuarts design, it would Y split and drive one long silencer box. The registers would shoot horizontally out the fronts of the silencer boxes, eliminating the need for any trunk with duct liner or $200 registers (yes, the ones I currently have in my design are expensive ass linear slot Nailor's).

Concerns with option #2:
- More MDF and duct liner as well as 8" duct and flex duct. However, I'm sure it will all be much cheaper than the trunk with duct liner and Nailor register.
- Extending the silencer outlet sleeves to ensure laminar air might look ugly as hell.
- Now the entire wall/ceiling corner will be silencer and prevent bass trapping usage.
- Bass traps in the corners will be slightly messed up in the corners due to the register openings.

I'd like anyone's opinion on these new dilemmas if possible please. Thanks for following and any ideas you guys have!

Also, for anyone reading this trying to learn, do not put your door far in the corner like it is in my design. This was unavoidable for me and I'm sure it will hinder the rooms acoustics as I won't be able to bass trap much there. I am building this room entirely inside out, so that will give me a few more inches in the corner for bass trap depth.

Greg

ISO HVAC:

No one has chimed in, but so far I think I'm going to stick with my original design. I realized I can just flip the trunk and register positions which will allow me to have only 3 baffles in the silencer boxes. Like this: And as usual, jumping around on my design, I tackled ray tracing... again.

I tried sliding my entire front wall assembly back into the room which would allow me to mount a sub into the front wall eventually and have it flush with the window wall. This didn't turn out good. I would have had to angle my speakers even further in and I'd be going in circles. The biggest reason I wanted to move the speakers further into the room would be to achieve a larger RFZ sphere around my head in the vertical plane. Extending the side walls out fixed my horizontal rays amazingly. Check it: So, after moving the front wall back to the way I had it, I re-designed the cloud. It's different than I ever imagined, but it seems to work well. I have over 2 feet of RFZ sphere around my head now. Check it: And a view from the back of the control room: The clouds are weird textures with transparent bottoms, but you get the idea. I think I'm going to add little wings to the sides of the cloud and back light them. This new cloud will allow a very large non-hard backed first section which will rule for bass trapping.

Please chime in about any and all of this stuff, friends!

Thanks for following and pointing out any awesome or horrible things I've come up with thus far.

Greg

Gregwor wrote: ISO HVAC:

No one has chimed in, but so far I think I'm going to stick with my original design. I realized I can just flip the trunk and register positions which will allow me to have only 3 baffles in the silencer boxes. Like this:

Hi Greg, struggling to see how flipping them like this allows you not to have a 4th baffle over the other design, but you seem to know what you're doing with it so all seems good.

Gregwor wrote:Do my arrows and text boxes help explain the issue better?

They do yes thanks. If the walls are fixed directly to the steel jack posts I wouldn't worry about additional noggins, those connections will probably be far more secure than the adjacent timber sections. If you're worried about the timber twisting with the door swinging on them, you could put some noggins in (rotate them 90degrees on edge if they fit and you won't need to rip them down.)

Gregwor wrote:So, after moving the front wall back to the way I had it, I re-designed the cloud. It's different than I ever imagined, but it seems to work well. I have over 2 feet of RFZ sphere around my head now. Check it:

I like it a lot. The angled bass trap at the front near the window is nice, you could probably get some nice long hangers or wave guides up there behind some thick absorption. Have you considered the facing on that section yet? Plastic strips or wood could be cool for not sucking the top end out, but you'll probably need to wait to measure the room first.

The RFZ looks good btw. You thought about your back wall yet?

Gregwor wrote:So, after moving the front wall back to the way I had it, I re-designed the cloud. It's different than I ever imagined, but it seems to work well. I have over 2 feet of RFZ sphere around my head now. Check it:

Oh quick note! I realised when playing on sketchup the other night, if you trace the vertical RFZ from a single speaker at the correct angle, it's a little different, especially when angled clouds come into play. This makes sense, the distance to your ears is greater from a speaker, than from the midpoint of the two speakers. This means the rfz falls closer to your head then it seems on a ray trace eminating from the mid point of the speakers.

If you want to ray trace using the speaker angle add the rays to the speaker component itself and the rotation axes will be relational to the speaker rotation, so you can still use the handy red, blue and green axes with your protractor tool