John Sayers' Recording Studio Design Forum Archive

Hello studio gurus,

I am in the late planning stages of my first REAL build. I have one half of my large 2 car garage (set behind the house) available to me. The inside measurements of that side currently before my inner walls are 14' x 25'6" x 8'4" After nearly a year of serious research here and GS forums, as well as Rod's book, I believe I have most of this project figured out, including my HVAC, electrical, the additional braces my roof will need, roof venting, approximate room layout and construction technique. I could not however find a clear answer to last major question i need to finalize a print.

I have decided to go with a single large multi-purpose room. I am a big proponent of tracking when possible or reamping/DI on instruments so iso booths don't seem necessary and I would rather have a bigger room instead of separate live and CR.

This space will be primarily for mixing and tracking (in that order of importance). I work with everything from some modern country to pop to classic rock to ska/punk. So there will be some volume created here but neighbors are 100' away and very accepting due to my self-imposed "No live drums after 9" policy. Isolation is basically to allow me to mix at around 75-80db at night and keep the quiet neighborhood sounds out of my mics when tracking. With my garage the way I found it when I moved it I get readings of about 30-40db when traffic goes by and about 50 when my neighbor mows his lawn. And its easy enough to not record for that 45 min a week.

The first sketch up drawing is basically my garage as it stands. The foundation under the walls was poured separately from the car bays slightly decoupling my floor. Its at least 14" of solid concrete so other than a nice epoxy paint job... my floors are done. There are 2 normal lifting style panel garage doors, but studs will be bolted to the inside of the door on the studio side and plywood toe nailed in between these new studs and then 5/8 drywall glued/screwed to the plywood also between the studs. That will be tied in on either side to the existing walls essentially making the garage door a rigid part of the outer structure and obviously not opening so that the rails can be marked and removed for re-installing if we were to sell the house (not likely in the next 10-12 years). This will essentially cost me 8" of overall length, but I was given the condition of leaving the garage doors. (You can fight city hall, not your wife )

The sheeting you see is currently plywood and 5/8 drywall will be cut to fit between the studs of the existing walls. A free-standing room-in-room design will be built inside with double drywall in the inside of those studs and standard pink fluffy insulation between the 2 assemblies. The window at the back of the room will be removed, framed over, and treated as solid wall. My monitors will be placed on this end of the room, opposite the existing garage door, projecting the long way in the room.

The other side of the garage will basically remain untouched as I still need somewhere to park one vehicle and that back storage area for other standard "garage-type things". I realize that there may be some of a 3-leaf effect happening with the other side of the garage, but I am a little unclear as to what constitutes a leaf if it is still all part of the exterior structure. Worst case I'll open the non-studio garage door when I'm in the studio essentially eliminating that leaf. If someone could clear that up for me that would be nice, but it really won't change my plans to drastically.

My real dilemma lies in the design and shape of my inner ceiling. The roof over the studio and the center wall of the garage have already been built up to take the additional weight hanging between the roof joists and so I can safely remove the ties from the center to the outer wall. I can now utilize all of the space up to just below the existing roof, obviously minus the height required by the inner ceiling's joists. I know I don't want a flat 7.5' ceiling over the entire studio so I have 3 possible ideas on the issue.

Questions:

Option A: Should I keep the ceiling symmetrical and match the roof pitch from the center wall to make a peaked center ceiling? This would give me approx 8' at the edges and 10.5-11' in the center. I would definitely hang treatment in the peak even though it will be greater than an right angle.

Option B: Should I just match the existing roof all the way to the center wall? This would definitely break stereo symmetry above the listening position, but isn't that good for recording as well as that it would really give me a lot of additional volume with one wall at 8' high and the other at 13-14'.

Option C: Should I use a combination of the 2? What about ceiling type A for the first 1/3 or 1/2 or some fraction of the ceiling over the mix position for stereo imaging and ceiling type B at the back of the room where drums and amps will be tracked for the additional volume and asymmetry?

I would also like some advice on what type of treatment should be used in the higher ceiling, if option B is recommended for any part of the room.

The second sketch up drawing (forgive the sloppiness) is option C but illustrates both designs. You can also see how I was hoping to be able to use some of the additional volume for treatment as well.


Thanks in advance for taking the time to respond to this.
There is so much knowledge here in this community and I am grateful for whatever insight you can give.

Jacob

Welcome Jacob, and what a great first post!

There are 2 normal lifting style panel garage doors, but studs will be bolted to the inside of the door on the studio side and plywood toe nailed in between these new studs and then 5/8 drywall glued/screwed to the plywood also between the studs.

Why don't you build an inside out wall to cover your garage door? Leave a little space between the sheathing and your door for insulation. Of course, seal it all off with studs on the sides and top as well.

A free-standing room-in-room design will be built inside with double drywall in the inside of those studs and standard pink fluffy insulation between the 2 assemblies.

I see "standard pink fluffy insulation" written all the time. It's important to buy the correct pink fluffy insulation though. Most R value fiberglass insulation is manufactured to be as light weight as possible. It is often so light that it does not work for what we need acoustically.

Here are those densities:

Fibreglass in kg/m^3
High Freq = around 40 (others say 60-80)
Mid Freq = around 35
Low Freq = 20-25

Mineral Wool in kg/m^3
High Freq = around 65 (others say 90-120)
Mid Freq = around 55
Low Freq = around 30 (others say 40-45)

The other side of the garage will basically remain untouched as I still need somewhere to park one vehicle and that back storage area for other standard "garage-type things". I realize that there may be some of a 3-leaf effect happening with the other side of the garage, but I am a little unclear as to what constitutes a leaf if it is still all part of the exterior structure. Worst case I'll open the non-studio garage door when I'm in the studio essentially eliminating that leaf. If someone could clear that up for me that would be nice, but it really won't change my plans to drastically.

I'm guessing that the distance to the outside sheathing on your vehicle garage wall is so great, and that the sheathing is so light in comparison to your studio sheathing, that the effect is not worth worrying about.

Option C: Should I use a combination of the 2? What about ceiling type A for the first 1/3 or 1/2 or some fraction of the ceiling over the mix position for stereo imaging and ceiling type B at the back of the room where drums and amps will be tracked for the additional volume and asymmetry?

On this specific computer I don't have the newest SketchUp so I was unable to open your files tonight, but from what you described, I think Option C would be the best. Everything you mentioned about it - symmetry for the first half as well as maximum room volume - these are the important things.

I would also like some advice on what type of treatment should be used in the higher ceiling, if option B is recommended for any part of the room.

If it is a multipurpose room, you'll need variable acoustic devices.

Greg

Thank you so much for the quick reply.

Gregwor wrote: Welcome Jacob, and what a great first post!

Thanks Greg! I went as far as to even print out the rules for the forum and check them off as I went just to make sure I didn't forget anything.

Gregwor wrote: Why don't you build an inside out wall to cover your garage door? Leave a little space between the sheathing and your door for insulation. Of course, seal it all off with studs on the sides and top as well.

I think that is roughly what I was planning, however I was going to bolt the new wall directly to the garage door. I don't want to misinterpret... is the image below similar to what you are thinking?

Gregwor wrote: I see "standard pink fluffy insulation" written all the time. It's important to buy the correct pink fluffy insulation though. Most R value fiberglass insulation is manufactured to be as light weight as possible. It is often so light that it does not work for what we need acoustically.

This is why I love this site. I was under the impression that the insulation between my two independent wall assemblies was more about thermal insulation. Is it safe to assume that in that cavity I should primarily be concerned with low frequency?

Gregwor wrote: I'm guessing that the distance to the outside sheathing on your vehicle garage wall is so great, and that the sheathing is so light in comparison to your studio sheathing, that the effect is not worth worrying about.

That's what my guy was telling me, thank you for the affirmation.

Gregwor wrote: On this specific computer I don't have the newest SketchUp so I was unable to open your files tonight, but from what you described, I think Option C would be the best. Everything you mentioned about it - symmetry for the first half as well as maximum room volume - these are the important things.

Excellent! Would you have a recommendation for a ratio of Option 1:Option 2? If I am sitting .375 of the entire room length from the front wall I obviously need the symmetrical ceiling over and slightly behind my head, but how far should I go before I change to the other ceiling? I have a feeling that 50% is not good, because I've learned perfect multiples are rarely good in studio construction. Or is this a case that doesn't matter as much?

Gregwor wrote: If it is a multipurpose room, you'll need variable acoustic devices.

I had to do a little research as to what you meant, but I found a thread where you and Stuart were discussing this and he had even posted some pictures. I was actually starting to work on some plans for very similar type treatments. Would you still treat the front of the room in a more traditional/static fashion and keep these variable treatments reserved mainly for the rear tracking area of the room? Or variable throughout?
One idea I had was to actually use a winch type mechanism to change the angle of a slotted diffusor over a large trap at the top of the slanted rear ceiling, like lowering a chandelier. Hopefully someone can tell me whether or not this is nonsense before I get to carried away with the design for it You can see a sketch of it in the other image here.


Thanks again for your input, I really do appreciate it and I will do my best to not ask questions that are easily looked up here. Although I must admit that I often feel as though EVERYTHING I could ever possibly ask has been discussed on here, but the sheer volume of information makes finding it a daunting task.

Jacob

I went as far as to even print out the rules for the forum and check them off as I went just to make sure I didn't forget anything.

I think that is roughly what I was planning, however I was going to bolt the new wall directly to the garage door. I don't want to misinterpret... is the image below similar to what you are thinking?

Yes that's what I was thinking. Depending on how thick/heavy your door is, you may need to leave a fair gap for your insulation to live though.

Is it safe to assume that in that cavity I should primarily be concerned with low frequency?

Well, you can calculate the frequency, but yes, aim for low frequencies.

Excellent! Would you have a recommendation for a ratio of Option 1:Option 2? If I am sitting .375 of the entire room length from the front wall I obviously need the symmetrical ceiling over and slightly behind my head, but how far should I go before I change to the other ceiling? I have a feeling that 50% is not good, because I've learned perfect multiples are rarely good in studio construction. Or is this a case that doesn't matter as much?

You're probably good to open it up after your listening position. The way in which you are opening it up should not apply to the 50% fear you mention.

Would you still treat the front of the room in a more traditional/static fashion and keep these variable treatments reserved mainly for the rear tracking area of the room? Or variable throughout?

Correct. The front half of the room in a mixing room is pretty static in the sense of material and angles and such. The rear part can more easily be changed. Something you could maybe implement is some diffusion at the center portion of your front wall during tracking sessions as it would be far from your instruments.

One idea I had was to actually use a winch type mechanism to change the angle of a slotted diffusor over a large trap at the top of the slanted rear ceiling, like lowering a chandelier. Hopefully someone can tell me whether or not this is nonsense before I get to carried away with the design for it You can see a sketch of it in the other image here.

I would suggest you read the master handbook of acoustics to get a better grasp on the concepts of acoustic treatment devices. The reason I say that is because your slotted device is not a true diffuser.

Thanks again for your input, I really do appreciate it and I will do my best to not ask questions that are easily looked up here. Although I must admit that I often feel as though EVERYTHING I could ever possibly ask has been discussed on here, but the sheer volume of information makes finding it a daunting task.

The search feature works quite well, but don't be afraid to ask on your thread here again. I feel that a lot of the old information is sparse. Information on things such as silencer boxes from years prior seem to be very outdated. In the last 8 months or so I think a lot more detailed information has been provided.

Greg

Gregwor wrote: Yes that's what I was thinking. Depending on how thick/heavy your door is, you may need to leave a fair gap for your insulation to live though.

If the inside out wall is mounted directly to the garage door wouldn't that make it part of the same leaf and therefore negligible?

Gregwor wrote: You're probably good to open it up after your listening position. The way in which you are opening it up should not apply to the 50% fear you mention.

Cool, then the ceiling can change at whatever stud/joint near the middle of the room I fancy.

Gregwor wrote: Something you could maybe implement is some diffusion at the center portion of your front wall during tracking sessions as it would be far from your instruments.

That makes perfect sense. In contrast the the absorbtion that would normally be up there that would really liven on the room.

Gregwor wrote: I would suggest you read the master handbook of acoustics to get a better grasp on the concepts of acoustic treatment devices. The reason I say that is because your slotted device is not a true diffuser.

I realize what's in that sketch is nonsense, I just made some random rectangles on that shape for effect. I was actually thinking about putting a large panel of a qd type possible with some normal traps between. My real question was if having a "damper" style treatment over the large trap at the peak would be considered a useful variable device.

I had already planned on hinging several different panels around the rear of the room simply for getting different color for different mics on different sources. I plan on color-coding the different sides so that I can easily flip them all back to their "mixing" positions when I want accuracy.

I did decide to the book though yesterday. Very informative, not too far thru it yet. I wish I had paid more attention to logarithms back in Calc.

Gregwor wrote: The search feature works quite well, but don't be afraid to ask on your thread here again. I feel that a lot of the old information is sparse. Information on things such as silencer boxes from years prior seem to be very outdated. In the last 8 months or so I think a lot more detailed information has been provided.

I do have one question at the moment that I seem to never see a definitive answer to: When using corner traps, is there a single best way to construct them? Air gaps vs solid 703 (or equiv) vs 703 with lighter behind it vs alternating layers? I fear I know the answer... measure... that just seems so far away and I want to start drawing prints and material lists now.

But I did just get home to my first measurement microphone in the mail today!!!! So I will be learning REW for the next several days.

As always thanks for the help!

Jacob

whitejacob6 wrote:Option A: Should I keep the ceiling symmetrical and match the roof pitch from the center wall to make a peaked center ceiling? This would give me approx 8' at the edges and 10.5-11' in the center. I would definitely hang treatment in the peak even though it will be greater than an right angle.

Jacob PM'd me at Facebook and asked for my advice here. But Greg is giving fine advice so I don't have much else to offer! And I don't have Sketchup so I can't even look at the layout. I do agree with having a peaked ceiling, and I was going to suggest treating the area under the peak. But you already know that needs to be done. I wish I had more of use to offer!

--Ethan

It's really good to see you back on the forum, Ethan! It's been way too long!

- Stuart -

Thanks Stuart. I've been off doing other things. Mostly arguing with audiophile idiots on Facebook. But also made a second edition of my Audio Expert book, and still help out at RealTraps though just part time. I also got back to electronics, and designed this device to prove that expensive RCA wires are bullshit:

The Null Tester

Mostly arguing with audiophile idiots on Facebook

Wow! You must be a REAL sucker for punishment, Ethan! Some of those guys are worse than conspiracy theorists in their extreme babbling insanity. I've tried to explain to them a few times in a few places how electricity works, but there's just no getting through. They really are convinced that there's some ethereal property to their wizardly wiring that cannot be measured in any electrical way... even though the entire purpose of those wires is to convey electrical signals.

and designed this device to prove that expensive RCA wires are bullshit:

What? You mean that US$ 10,000 wires made from pixie dust and unicorn hair won't make my stereo sound any better? Oh NO!!! I'm devastated!!!

Kudos for convincingly putting to death one of the most persistent (and most stupid!) myths in the audiophile industry, that has been around for many, many years. To anyone with a grain of common sense, and a basic understanding of logic, your video absolutely kills it. I'll bet that you didn't win many new friends among the manufacturers and vendors of magical products... You've probably been black-listed in many places now... And I'll bet YouTube has already received more than one complaint about your "hate speech" video, that must be removed from the internet, because it upsets their delicate sensibilities (not to mention their large stream of cash that flows very liberally from the terminally gullible)... It really would not surprise me that many have complained. How dare you refer to their bullshit, as "bullshit"!


You should use your Null Tester to also check the properties of (gasp!) US$ 10,000 speaker cables that you can use to hook up your US$ 80,000 power amplifier to your US$ 100,000 speakers, and also test the (Please No!) US$ 10,000 power cables that you can use to plug in said amplifier and only convey pure, clean electricity to it...

(I'm still waiting for one of those manufacturers to come up with a way to create half million dollar super-conducting quantum equalizer cables that require supplies of liquid nitrogen to cool the conductors to perfection... I'm sure they would claim that your null tester doesn't have the capability to detect such perfection, because it "only" goes to 110 dB... )

One question I've always wanted to ask the US$ 10,000 power cable folks, is this: "Assuming that your 3 foot US$ 10,000 power cable really does have perfect "whatever" capabilities that allow it to convey the power impeccably from the wall outlet to the equipment, with -5,000 dB of distortion... even if that is true, then what about the hundreds of miles of ordinary copper and aluminium cable on the OTHER side of the wall outlet, that goes all the way back to the power station that generated the power? Are you REALLY trying to tell me that your 3 feet of perfection can somehow overcome all of those those hundreds of miles of terribly imbalanced "whatever", including all the transformers, connections, and switch-gear along the way?"

I loved the video, Ethan. Excellent! Very useful. It probably won't have much effect on the True Believers, of course: there's no redemption for pure stupidity....

Maybe if you told the audiophiles that one of the chips you used is totally oxygen free, nitrogen free, carbon free, gluten free, cholesterol free, and even uranium free, and one of the capacitors even has several drops of purest snake oil inside it? Maybe that would convince them...

As the saying goes: you can't fix stupid.


- Stuart -

At last some common sense! I've had that same argument dozens of times. I was almost lynched once because in a pinch I used a piece of household Romex to make a power cable. My only reply... "What do you think is on the other side of the outlet?"

Where would you guys draw the line as far as mic cables, especially in the studio? (25' max no cross building 250'ers) I deal with control and feedback signals in an industrial setting all the time, so I know quality in low power signal cable makes a difference. Thoughts?
Side note my patch bay is wired mostly with extra Allen Bradley control cable.


Stuart, would you be willing to give me your take on a hinged "trap door" style diffuser over a bass trap like my poor ceiling sketchup drawing above? I noticed in a different thread you had some experience with variable acoustic devices.

Jacob

Where would you guys draw the line as far as mic cables, especially in the studio?

You mean as far as quality is concerned? I don't mind spending a bit extra to get good quality cables, simply because they wear better, are easier to solder, tougher, easier to work with, etc. Names like Belden, Canare, Mogami, etc. are all worth the extra expense, IMHO. Ditto Neutrik connectors. But you sure won't catch me paying hundreds of dollars per meter! Not even tens of dollars....

Stuart, would you be willing to give me your take on a hinged "trap door" style diffuser over a bass trap like my poor ceiling sketchup drawing above?

Sure! But which SketchUp is that? I guess I must have missed it...

- Stuart -

Soundman2020 wrote: Names like Belden, Canare, Mogami, etc. are all worth the extra expense, IMHO.

Great. I'm a fan of Belden and I think I can buy direct through work. Also I don't know if they make a cable of mic specs but I recently discovered the Lutze Cable brand. I love it for transmitting digital and analog encoder signals through large high voltage machinery without distortion. Makes sense it would work for mics...

Soundman2020 wrote: But you sure won't catch me paying hundreds of dollars per meter! Not even tens of dollars....

Yeah... some of the cables out there seem completely ridiculous to me.

Soundman2020 wrote: Sure! But which SketchUp is that? I guess I must have missed it...

Thanks. It's called variable for ceiling. It's in the same post as the jpg about the garage door. For the record I know that what's in the drawing (looks like a large plate with some rectangles cut out) won't be a useful treatment. Its merely representative of the concept.

My logic is that changing the angle of something (possibly a long qd style diffuser) in relationship to the peak of the ceiling AND like a damper, changing the amount of air flow and direct exposure to the chunk style trap beyond it at the very peak should allow me to vary the sound and perceived size of the room. After all this is going to be a single mixing and tracking room.

Lowered to provide as much absorption as possible during mixing.
Raised to span across the trap to provide HF reflection during tracking for maximum liveliness.
Or anywhere in between depending on instrumentation and feel of the track.

In my head it seems like a great idea, but I don't have much hands on knowledge with acoustic treatment... Especially variable ones.

Jacob

Hello,

So it seems as usual life has a way of happening and studio construction is moving much slower than expected. I have my new service ran to the garage and my outer shell nearly done. I literally have hundreds of hours in to the planning and of course the slow pace has given me time to re-re-rethink things. Which may not be a bad thing...

I thought I had my HVAC system figured out, and while a separate air handler and ducting may be the best way to go, once I started construction on the gigantic silencers I would need, I started to revisit the mini-split. I also have recently found an excellent deal on the mitsubishi ductless line thru a local contractor I deal with thru work. My calculations given climate, gear, and max room capacity come up around 15k BTU.

So my question now is where would you recommend placing the cooling head in the room as well as the air intake/outlets. I have attached a sketchup of the approx shape of the room (the generic lump in the middle is the console/desk). Part of my thinks the front (south) wall so that it is close to my desk where the most heat will probably be. I am also considering the center of the north wall (with the door) which would put it very centrally located for even cooling. But I also thought about the top of the tall north wall because thats where the hot humid air is going to be. I see merit with all the locations and hence I differ to those who know more than me.

Keep in mind I can basically run my fresh air in/out from anywhere but the south wall. So not too much limitations there.

Thanks again in advance for all of your help.


Jacob

I don't have SketchUp on this computer right now but I can say there is no hard rule on where to put the condensor unit. Personally, I would put it on the rear wall and have my fresh air come in over top of the unit. Then, I would have the return air inlets at the front of the room. If that wasn't possible, I would go side to side.

Note: even though you can get away with way way smaller silencer boxes as you only have to pass ~30% of the amount of air in/out of your room, the size of these boxes REALLY matters when it comes to the amount of insertion loss you will achieve with them. The bigger the better. Having said that, make them as large as you possibly can. You can still get away with only having 3 baffles in the boxes but the impedance mismatch is what is going to make all the difference.

Greg

Topic review - Need feedback on possible ceiling designs
Author Message
Gregwor
Post subject: Re: Need feedback on possible ceiling designs Reply with quote
I don't have SketchUp on this computer right now but I can say there is no hard rule on where to put the condensor unit. Personally, I would put it on the rear wall and have my fresh air come in over top of the unit. Then, I would have the return air inlets at the front of the room. If that wasn't possible, I would go side to side.

Note: even though you can get away with way way smaller silencer boxes as you only have to pass ~30% of the amount of air in/out of your room, the size of these boxes REALLY matters when it comes to the amount of insertion loss you will achieve with them.

Thanks for the reply. My fresh air needed is a max of 90cfm. I can get this well under 300fps with 4" round ducting. My plan was to make the internal cross section of my silencers 4x4 square. Do you think that would be sufficient?

I was also contemplating a recovery unit, but if my exhaust is 25 ft away at the other end of the room I feel like that's not going to be possible. Any thoughts?

Finally someone had mentioned to me adding additional fans inside the room for circulation. The mini split i'm looking at has a cfm of about 600 cfm which is what I was originally designing my ducted system for, so I feel additional fans would be unnecessary. Am I on track there?

Thanks again for the help. I can't stress how much I appreciate it.

Jacob