Multiple Room Home Studio Build - Mesa, AZ

I appreciate your response, but I can't fully agree. Just because I have not made provisions for soffit mounting does not mean I've not been planning. As far as HVAC, I have provisions for cooling and heat, and I studied as well as met with several local studio owners who employ the same type of room design in their studios (size included), and 3 of them do not have fresh air or exhaust provisions. Their mini split systems handle cooling, and they open doors during breaks and between sessions. A 3.5 ton 4 zone mini split should help keep people comfortable. As for oxygen... I picked several studio owner's brains on this one, and I just don't think I'll have enough people in the room to have to worry about people turning blue in the face and passing out. In fact, I worked 12' under ground for several years in a sealed pyramid for 12-14 hours a day with 4-5 people in the room with me, and never had any issues. I will be supplementing the control room with central air, so that will be feeding fresh oxygen into the room during long hours in there. I've never, EVER, had a session run where we did not open doors or take breaks every hour or two tops. Stopping the build is not an option. My builder and my helpers are here for a limited time, and will not be available to me again once they're gone, nor will I be able to hire the work out. I won't go into all of the details, but I was forced to retreat from my previous studio due to unethical behavior from a partner. During that time, I purchased a house and was givin a design & build deadline. I had 2 months to purchase a house, finish my studio design plans, and we had to start putting hammers to nails. I'm not looking for perfect, but we're going for pretty damn good. So I was hoping that this forum would help me find answers and solutions to some of the roadblocks and questions I may have along the way. I've got to make proactive decisions, not run away from or sleep on them since my help is only available for a limited time. Once they're gone, I'll need to have most of the work done if I want to continue to work in this industry. I was basically forced into designing and building my own facility, and quitting is not an option. It's been a very rough 8 months finishing projects from other studios.

I had some time this afternoon to look more into John's soffit design... A couple of questions. I assume this is being placed up against a room that is already drywalled? Is there a minimum amount of airspace behind the speaker (where the soffit ports are drilled), as well as in the cavity behind the port that is filled with loose insulation? Do the speakers need to sit on a neoprene pad? Sorry if I'm asking the obvious, but I assume this can be placed at the corners of the room, and placed at 90 degrees from the listening position? I don't think it's too late to integrate these plans into the room design. I just didn't think that I'd ever soffit mount "near fields", but after reading through more threads -- I see how beneficial it is, and really isn't too hard to design into the room as long as the front wall has space, which in my case, I do! Is the image I attached the most current design without the use of concrete?

I assume this is being placed up against a room that is already drywalled?

The inner-leaf drywall? Yes. Correct. Well, that's a qualified "yes", as this a bit confusing. Technically, the front panel of the soffit becomes the new inner-leaf, since that's the hard, rigid, massive surface that the sound waves encounter at the front of the room, except for the bottom part, where the hangers are.... so it gets complicated. But yes, normally you complete the inner-leaf, then add the soffit unit in front of that, firmly anchored to it.

Is there a minimum amount of airspace behind the speaker (where the soffit ports are drilled)

You only really need enough space there to allow good air flow, and for the cables: XLR connectors are long, and need space at the back to allow for that. So there is no specific requirement to have a certain gap due to acoustic reasons: just practical ones: cooling airflow and cable entry.

as well as in the cavity behind the port that is filled with loose insulation?

The entire front panel is a continuous, unbroken surface, so the depth of the speaker plus te spaces that you need behind that will also define the depth of that cavity at the top, as well as the hanger cavity at the bottom. Those all sit behind the front panel, whose depth is defined by the speaker plus gaps.

Do the speakers need to sit on a neoprene pad?

That's one way of doing it, yes. There are several methods for building a soffit, but only two are really used here on the forum. One method has the speaker firmly attached to the wall framing itself, very rigidly, with the speaker held rigidly in a tight-fitting box, then the front panel goes on a separate decoupled frame, leaving a tiny gap around where the speaker pokes through. So the speaker and box are on different mountings, decoupled. The other method (which I like more, personally) is to attach the front panel to the rest of the soffit, very firmly and rigidly, but then decouple just the speaker, with rubber mounts as you suggest. In this case, there is also a small gap between the speaker itself and the soffit panel, just like with the other method. In both cases, the key is to physically decouple the speaker from the panel, so that the speaker cannot transmit any vibrations into the panel, which would amplify them and transmit them into the room. There are various ways of doing that decoupling of the speaker, with rubber. As long as there are no hard connections, and the speaker is still held in place, that's what matters.

but I assume this can be placed at the corners of the room, and placed at 90 degrees from the listening position?

You still use the same basic listening geometry as for stand-mounted speakers: 30° toe-in, 1.2 meter height of the acoustic axis, 38% starting point for the mix position, speakers separated enough so that the acoustic axes are aimed just outside the engineers ears, intersecting about 20 cm behind his head at 60°, etc. None of that changes. It's the same as always, soffit or no soffit. The only difference is that the speaker is now surrounded with the "infinite baffle" that solves all of the usual artifacts, all at once. That baffle is then "blended" into the side walls, front wall, and ceiling, avoiding sharp discontinuities. And since the baffles are part of the RFZ system, that "blending" usually consists of a section of wall at a different angle, that joins the edge of the soffit to the side wall. That completes, the RFZ plan, in the horizontal plane. The angle of that "angled wall section" depends on the specific room, and needs to be ray-traced. There's no "one size fits all" angle that you can use: it has to be figured out for each room, since all rooms are different. The final out come is the cleanest, clearest, sharpest, tightest sound you ever heard from your speakers, since there are no artifacts to distort it.

I don't think it's too late to integrate these plans into the room design.

Great! :) Smart move.

I just didn't think that I'd ever soffit mount "near fields",

That's one of my pet peeves! Technically, there is no definition of what a "near field" monitor actually is! No definition for "far field monitor" either. Ask five manufacturers what the definition is, and you'll get 5 very different, totally contradictory, answers. If you don't believe, do a google search for "Definition of near field studio monitor", and see what you get... :) In reality, this is just marketing hype: anyone can build a speaker, slap it in a box that says "near field" on it, and nobody else can say that they are right or wrong. Yes, we all "know" what a near-field is, but there is no definition. My near-field monitor might be your far-field monitor, or vice-versa. It is all just marketing hype. In fact, "near-field" and "far-field" are far more related to the ROOM, than to the speaker. There actually are clear concepts in acoustics here, which I won't bore you with, but basically it is the room that defines what "near" an "far" mean, NOT the speaker. So you sure can mount a "near-field" speaker in a soffit! Just like you can mount ANY speaker in a soffit, provided that it has no side or rear ports, and that you have a method for rolling off the bass. (Most professional speakers come with built in, but if not then it is simple to add.) Just because your speakers came in a box that said "Near field" on the side does NOT mean that they can only be used close up, sitting just behind the meter bridge.! Myth. In fact, (gasp!) you could even use far-fields just behind the meter bridge, if you really wanted to. As long as they are far enough away from your ears that the sound fields from the various drivers have merged coherently by the time they reach your ears, then you can quite happily do that, and call it a "near field" if you really feel like it! :) Do you smell some marketing hype going on here? We mix engineers tend to just swallow this stuff that the manufacturers feed us without question, but when you look under the hood and see how they work, things get a lot clearer...!

but after reading through more threads -- I see how beneficial it is, and really isn't too hard to design into the room as long as the front wall has space, which in my case, I do!

Yep! Exactly! The benefits far outweigh the extra cost and complexity... IMHO.

Is the image I attached the most current design without the use of concrete?

I think John has probably updated his designs many times since then, but the basic principle is the same. Take a look around the forum, and you'll see many variations in the way they are actually built, but the underlying concepts are the same. - Stuart -

Thanks for that last reply, Stuart! Will be implementing all of your tips in the build. I'm still considering at least a couple of exhaust fans in the live room and vocal booth to expunge old musty air. I'm still pretty certain that we'll not spend more than 2 hours without a break or listen back in the control room (fresh air fed). I've talked to a couple more people, and everyone so far seems to think that fresh air inlet for my studio should not be mandatory, but would be useful for keeping the air "clean" in the rooms without fresh air ventilation during sessions with larger groups (4-5 people in the live room simultaneously.) My thinking was by installing exhaust outlets in the room, with quit boxes for the ducting & fan noise, I could create a negative air pressure in the live room and iso booth, and positive air pressure coming in from the rest of the house when the studio doors are left in their default open position when the tracking areas are not in use. Once the old air is out, and fresh air is in, the doors can be closed and tracking can resume. Mini splits will keep the environments dehumidified and comfortable when tracking. While I know fresh supply, and exhaust are important, and I'm not trying to be lazy. But, I want to be realistic with my room's needs -- as well as keep people comfortable and safe. I've run sessions full time for 7 years now, and have never been locked into a single room for more than a couple of hours. I don't ever have more than 5-6 people in the live room when tracking. I'd appreciate your input on this subject, keeping in mind -- I do not mind keeping doors open when not tracking. In fact, I prefer it. With respect & gratitude, Nick ps attached are some progress reports of work done! Only two walls and a ceiling left for framing, and then next 4 weeks I'll be dealing with electrician, audio cable runs, final gap seals, and insulation installation. This is also the time that I can make exhaust and intake provisions if absolutely necessary for my space.

Here are some progress photos! Descriptions attached to photos. All we have left before drywall is putting the clips & hat channel up on two of the rooms, putty pad installation, need to finish insulation and replacing the crappy labels on my cables. Monday is the big day, and I must say that I'm thrilled about it! ps Sorry the last image is rotated. I wish a module was installed in the forum so that we could "edit" photos :)

Sorry this thread has lost momentum. There hasn't been much participation or interest in this thread so I stopped posting frequent updates & questions. For anyone interested -- here's an update of the build process. I'm just under 4 months in, as seen in the video. https://www.youtube.com/watch?v=mY-VjjS7m68 Next up are doors, windows, and recessed lighting soffits.

Captions attached to images.

Here are a few shots of drywall delivery

Looking good! :) - Stuart -

Here's a photo of the live room -> vocal booth window construction. Following John's instructions except plan on butting some foam type of foam/rubber up against the glass in between the window cleats and the glass. The glass will sit on 1/4" thick cork, and oriented in a "\ /" shape. The glass starts about midway through the stud, and extends out to flush with the drywall, or a little past it. I tried to find the best compromise of maintaining airgap and keeping the window from protruding out into the room too far. The bottom sills of each window (except for the control room) is extended a bit to act as a shelf and accommodate a light, microphones or amp heads. To seal the gap created by the shims, on top of a heavy layer of liquid nail between the top and sill and bottom plate for the opening, I plan on using backerrod to fill the inner most part of the gap between the wall and window framing and then filling that space with expanding door & window foam up to about 1/4" from the drywall surface, and then I'll use acoustic caulk to seal the last bit. Any problems Glass thicknesses will be 3/4" and 1/2". I plan to put the 3/4" on the vocal booth side, since it's technically rated for higher isolation, and I really want that room quiet in comparison to my expectations for the live room. We'll glaze the edges and caulk both inside and outside between the glass and cleats. The glass sealing order goes like this correct? Cleat -> 1/4" rubber/closed cell foam -> Glass (sitting on cork) -> 1/4" rubber/closed cell foam -> cleat then seal with caulking around all edges on both sides? Am I missing anything at this point in terms of sealing the window?

Here are a few more photos of the progress... Control room doors without seals on them. Solid core 1 3/4". I'll likely beef them up soon with some MDF on the inside along with some insulation wrapped in fabric. Using the "Type K" trunk seal for the doors. - Door leading into recording studios - Temporary threshold to keep cabling safe. Some photos of the window openings: - Angles at the top of the frame protrude to help block light glare from the soffet lighting mounted in the ceiling.

Also wanted to confirm.... The gap between my 2 window frames in each opening is much larger than 1/4". I figured since I'll be covering the gap with rigid fiberglass, the gap would not be revealed anyways. Is this going to be a problem, or do I need to close that gap up to be more minimal?

Just have to finish the inside cleats, and order glass for the openings.

Anyone, or maybe Stuart around to help field some of my question perhaps? Also, more photos of the window frames ready for glass. I'll fill the gaps between the window cleats with rigid fiberglass covered in fabric next. I was thinking about putting a layer of silica gel inside the fabric of the bottom panel that will go between the cleats. Will that be okay? Live room to vocal booth Live room to vocal booth Live room to control room Live room to control room

Thought I'd bump this thread with a video update... http://www.youtube.com/watch?v=lJIdCZdwEAk

*bump* hoping for a reply.

Also wanted to confirm.... The gap between my 2 window frames in each opening is much larger than 1/4". I figured since I'll be covering the gap with rigid fiberglass, the gap would not be revealed anyways. Is this going to be a problem, or do I need to close that gap up to be more minimal?

Which gap are you referring to? The shim gap around the edges of each window, or the gap between the two windows across the cavity? The gap across the cavity can be done with fabric-wrapped insulation, and at some place in there you need to have some silica gel beads spread around (but hidden visually), to absorb any moisture that might make it's way into the gap. The gap around the perimeters of the widows absolutely must be sealed up, and with enough mass to equal that of the drywall / glass. One way to do that is with baker rod and caulk. Push the backer rod in deep, making sure to get a good seal all around, then caulk it deep, then another layer of backer rod and another layer of caulk. That should bring you up to roughly the same mass. Don't use expanding foam in there: it could push the backer rod right out as it expands, plus it sets hard and brittle, doesn't have much mass, and is closed-cell. But I'm concerned about something else I see in the last set of photos: It looks like you have your electrical boxes poking through holes in the drywall. Several of them! I hope you sealed each of those very carefully with putty pads? If not, that can pretty much destroy your isolation. The general rule is that you should have one single penetration for bringing the power feed conduit into your room, and then distribute it from there internally. And that single penetration has go be done very carefully too. So I'm hoping that those boxes are very carefully sealed and also well beefed up with putty pads at the back? Just checking... - Stuart -

Soundman2020 wrote:

Which gap are you referring to? The shim gap around the edges of each window, or the gap between the two windows across the cavity?

I was referring to the gap between the two windows across the cavity. I had planned on wrapping rigid fiberglass with fabric, and placing silicca gel between the fiberglass and the fabric. So it sounds like I'll be okay? I had seen some people only shaving about 1/4-1/2" gap between the two window frames and filling that gap with rubber. I was just making sure that the two window frames did not need to be air tight from the wall assembly itself. The gap around the edges of the window has backer rod, DAP door & window foam, and I was planning on topping it off with acoustic sealant before putting on the trim. Do I need to tear out the foam? As far as the outlets, I did putty pad all of the outlets, and also caulked between the outlet and the drywall as we were adding leafs. Those pads aren't cheap! :\ Hopefully I'll be alright? Good to hear from you Stuart! Hope you're staying cool this summer. Nick

The gap around the edges of the window has backer rod, DAP door & window foam, and I was planning on topping it off with acoustic sealant before putting on the trim. Do I need to tear out the foam?

If you can get it out easily, then I would do that, as it's not doing much for you. The end goal here is to have that gap filled with the same mass (surface density), as the rest of the wall, and that foam doesn't have much mass at all. Neither does the backer rod. Caulk is about twice as dense as drywall (the colored stuff at least: the transparent stuff is a bight lighter), so you need about half as much thickness as your drywall. so if you have two layers of 5/8" drywall on there, then you need at least 5/8" of caulk. The backer rod is to ensure that there are good seals even if the caulk has a tiny gap that you didn't notice, and also that the caulk doesn't drip out the back of the gap. And if you do it in two layers (rod, caulk, rod, caulk) then you have twice the number of seals, and even more mass.

As far as the outlets, I did putty pad all of the outlets, and also caulked between the outlet and the drywall as we were adding leafs. Those pads aren't cheap! :\ Hopefully I'll be alright?

Sounds like you did it right. Not sure if you are using conduit or not, but if so then don't forget to seal the ends properly after all the wiring is in. And if you are not using conduit, then caulk the point where the wire comes through into the box, just to make sure...

Good to hear from you Stuart! Hope you're staying cool this summer.

:) Not where I am! It's mid winter here: temperatures are expected to hit freezing tonight, and it will be cold and rainy tomorrow... :( But thanks for the good wishes anyway! :) - Stuart -

Soundman2020 wrote:

:) Not where I am! It's mid winter here: temperatures are expected to hit freezing tonight, and it will be cold and rainy tomorrow... :(

d'oh.. I always forget that your seasons are reversed from ours in the states. I could use some of that freezing weather myself. 118F here on tomorrow! Can't wait to get the place painted and mini-splits running. Thankfully the 2 layers of insulation has prevented the rooms from exceeding 90F even during 115F days, often it doesn't even exceed 80F... Nice working weather! :)

Soundman2020 wrote:

If you can get it out easily, then I would do that, as it's not doing much for you. The end goal here is to have that gap filled with the same mass (surface density), as the rest of the wall, and that foam doesn't have much mass at all. Neither does the backer rod. Caulk is about twice as dense as drywall (the colored stuff at least: the transparent stuff is a bight lighter), so you need about half as much thickness as your drywall. so if you have two layers of 5/8" drywall on there, then you need at least 5/8" of caulk. The backer rod is to ensure that there are good seals even if the caulk has a tiny gap that you didn't notice, and also that the caulk doesn't drip out the back of the gap. And if you do it in two layers (rod, caulk, rod, caulk) then you have twice the number of seals, and even more mass.

Absolutely, I can trim back some of the foam, and get at least 5/8" of acoustic caulking in there, no problem! Thanks for catching that. I was actually a bit nervous about using that much foam knowing that it was lacking mass. I wasn't sure about the density of caulking vs drywall. Really good to know! I didn't run conduit. It was just going to be too expensive to run. That's also why I was forced to do away with single point of entry and running conduit on room side of the walls unfortunately. Hopefully putty pads on the cavity side, and caulking on the inside will not result in a ton of bleed. What do you recommend for sealing the holes around the back of the minisplits where the copper and drain pipes come into the rooms? As a side note regarding recessed lighting. A rep at Home Depot was pushing me to LED, and was insisting that I try their Cree LED's. Let me tell you all something... For a studio application, CREE LED's are no good! Hum central... It's LOUD! As I read in several threads and forums, many of these halogen replacement LED's hum due to the transformers inside of them. After some trial and error, I've finally found some luck with the Philips PAR30L Flood's (Model 420315). The color is pleasing, and best of all -- no hum! It even states "no hum" on the box, which was a bit hard for me to believe before hitting the register. I'd say they're quieter than a standard halogen filament burning, imo. Rock on! :D All the best, Nick

What do you recommend for sealing the holes around the back of the minisplits where the copper and drain pipes come into the rooms?

They didn't go through conduit either? If not, then I would first carefully seal all over with caulk, then shape putty pads around it to get some good mass built up again.

For a studio application, CREE LED's are no good! Hum central... It's LOUD!

Good to know!

I've finally found some luck with the Philips PAR30L Flood's (Model 420315).

I got some Philips units that turned out to be silent too, and also dimmable (not all LEDs can be dimmed, so if you plan to dim yours, check first). I am definitely NOT a fan of Philips in general, but that's all they had in the store in dimmable LEDs when I went in to buy them, and I must admit I am pleasantly surprised. Probably the first time in my life that I have not been disappointed by a Philips product! :) - Stuart -