New studio/house build including John’s small studio design

Hi Stuart, Yes the soffit angle was out of whack, maybe this happened when I rotated the room as I thought I always had them at close to if not at 30 degrees exactly. I am learning as I go but the intention after much reading has always been to have them set at 30 degrees. I have adjusted them so that they are now at 30 degrees as in the pic below. I'm hoping to not have to move the 2400mm sliding doors to the outside of the studio nor reduce their opening width. I will probably need to look at custom sized sliding doors between the CR and LR to make sure that I can get at least a 1200mm opening to load between the rooms. There is 1600mm between the soffits now when set at 30 degrees and I did make them a little less wide. I'm assuming that is ok. I also updated the fresh air part of the HVAC to be separate runs and placed the air in and air out at opposite ends for the CR as suggested to maximise airflow. It's been a long time coming! I'm going to be concentrating on getting the conduit and slab right now and also placing entry points in the outer leaf for the HVAC, power and ethernet. After the outer leaf is complete then the rest of the house build will most likely get finished before the inner leaf is tackled.

Hi, A quick update the slab prep with conduit has started.

Just checking here, Ben: is that conduit well weighted down and held firmly in place? If not, it can float right out of the concrete... You might also want to plug the ends of the conduit with bits of newspaper or something similar, to keep water, dirt, and splashed concrete out... - Stuart -

Hi Stuart, Thanks for the heads up. The conduit was weighted and tied down. When I checked after work I could not shake it or move it at all really. I am assuming that the builders will cap the conduit before pouring but I will check and request that today. The pour is scheduled for this Friday and will keep posting progress. Thanks, Ben

Hi Stuart, The conduit was covered with gaff tape prior to the pour to make sure that no concrete got in. I also talked to a local HVAC supplier on the weekend and he has suggested a Mitsubishi SEZ-KD35VA http://www.mitsubishielectric.com.au/1118.htm ducted system with a bulkhead unit fixed under the floor of the house and placed outside of the outer leaf and to the rear of the LR/CR (i.e. at the end where I have been planning HVAC would be anyway). This unit would also have a fresh air intake duct to supply fresh air into the system. The amount of fresh air would be balanced to ensure that the system recycles some cooled air for energy efficiency while also introducing a sufficient amount of fresh air at each pass. This balancing would occur during installation and then later it would be re-checked after the inner leaf is complete. This is instead of having a split in each room and a separate fresh/stale air system. The published sound pressure levels for the Mitsubishi SEZ-KD35VA seem to be good at 23db at low power and 33db for high power during cooling and heating. To prepare for the above system to be installed, the HVAC supplier has proposed that two besser blocks are left out at the rear of the outer leaf. These blocks would be toward the top of the wall, one to the far left and the other to the far right. A block is 390mm wide and 200mm tall and each gap would have 2 x 150mm diameter acoustically lined ducts passing through them (one to the CR and the other to LR) and into the air gap that runs between the inner and outer leafs. Currently I only have a 100mm air gap down the side walls, but, the HVAC installer suggested using 70mm structural pine rather than 90mm to get an extra 40mm and I am hoping to reduce the width of each room by a further 60mm to get the required 150mm wide air gap. I rechecked http://www.bobgolds.com/Mode/RoomModes.htm with this slight change in width and the results were unchanged from my earlier long post. The HVAC supplier also proposed that the ducts snake through several 90 degree turns to decrease any noise and that silencer boxes can be still be added inside the inner leaf if the snaking of the ducts does not negate all noise. He seems to think that silencer boxes will not be required. However, I want to get this right. At this stage I don't know what speed the incoming air will travelling at when it enters the CR and LR and don't want to hear any air noise when I'm soloing recorded tracks or setting up mics for recording! So I am still planning to connect the incoming and outgoing ducting to silencer boxes that will be located within the inner leaf of each room. So the suggested Mitsubishi bulkhead unit would have 6 connections if I am thinking correctly about what was communicated by the HVAC supplier: 2 outputs sending air via ducting to the LR and CR 2 inputs returning air via ducting from the LR and CR, and 1 fresh air intake to supply fresh air into the whole system 1 output that connects to the external compressor unit (also outside of the outer leaf and located at the side of the house). I will still place the air in and air out registers on opposite sides of each room and also at opposite ends of each room to maximise air flow through out. This solution was quoted as being quite a bit cheaper than installing 2 daikin ururu sarara's and a separate passive/active fresh/stale air system and the units quoted operating sound levels ranging from 23db-33db seem to be quite acceptable (especially given that the bulkhead unit can be mounted outside of the outer leaf along with the compressor). Also, given that I will not be able to start the inner leaf build until after the house builders have handed over this solution also appeals as it does seem simpler, i.e., all I would need to do now as part of the house build and outer leaf build is to leave out 2 besser blocks at the rear of the outer leaf. Then once the builders have core filled the outer leaf walls and the outer leaf sliding door and window are in then I can have 2 besser blocks loosely placed back in the gaps and slide them back out when I start on the inner leaf build and the HVAC is ready to be installed. I am also hoping to use the 2 outer leaf openings to get the power and ethernet runs through the outer leaf, into the air gap and then through to the inner leaf. Please note that I decided to not use extra conduit to get from the air gap into the inside of the inner leaf. Rather I have accepted that I will punch through the CR inner leaf once for power and once for ethernet and then seal as carefully as possible. I'll also punch through the LR inner leaf once to get power in. Once all cabling is inside the inner leafs then it will run inside the framing and all points and lights etc will be surface mounted. I hope that I do not lose too much isolation and end up regretting this decision. Stuart does the above HVAC solution sound ok to you? I will modify the sketch up file to reflect the above and post soon. If I do go this way then the biggest issue that I can see is making sure that the outer leaf is sealed carefully twice and also that the 4 places where each duct punches through the inner leaf wall are also carefully sealed. Can I also ask how I would go about sealing these two besser block gaps acoustically after the HVAC ducting, power and ethernet have been installed?

hey Ben, I've been away for a couple of months but just got back and read through your progress, and you're really nailing it! well done mate :D I remember the feeling of achievment once I had my slab down and it's a nice place to be. I know all the planing and prep can be tedious but it's the best way to go and you're doing it really well. looking forward to seeing the project as it moves forward :D cheers, steve

It's been a few more weeks and I thought I'd post a few pics of the outer leaf build underway. With any luck by the end of next week downstairs will be ready to be core filled and then on to the floated slab roof. The garage slab (above and behind the back wall) and some concrete work that joins the garage and the studio back wall also need to be completed before the actual house starts to take shape.

Oh yes .... been following this thread since the start. Great to see the structure underway ! Keep the cards, letters, picture coming. Nice to watch the dream become reality :)

Howdy, It has been a few weeks since I last posted and the house and studio build is still in progress. Below are a few updated pics that show the floated slab above the studio first being formed up, then after the pour and again with the form work removed. At the same time that the floated slab was poured the builders also poured the garage slab that can be seen in the pics below. You can also see two gaps that were left in the core filled outer leaf block work to allow for passive fresh air in and extracted stale air out. Once the house has been completed it will be quite easy to access this back wall of the studio from under the house. There will be plenty of headroom. This may be the last post for a few months now as the builders (at least at this point) are not working on the inner leaf, installing HVAC or completing the studio fit out. I am aiming to that work in conjunction with another specialist builder and with some help from friends and family after the actual house is complete. With any luck we may have a garage, the bearers and a floor down before the christmas break. A big shout out and many thanks again to Stuart for his knowledge and expertise that has been invaluable in getting me this far and also thanks everyone on the forums for their interest in both my little project and for posting and sharing their own knowledge and experiences too. Cheers, Ben

pics that show the floated slab above the studio

How is it floated? Not clear at all from the pics. Do you have any detailed pics of how you did that? It's always interesting to see that.

With any luck we may have a garage, the bearers and a floor down before the christmas break.

Hey! Christmas break is pretty much here, so I reckon it's time for an update! Don't be a stranger, now.... :) - Stuart -

Hi Stuart and fellow forum members, Sorry for the delay and happy new year to everyone. I hope everyone got to relax and had a great break over the holiday period! I did think that I had posted an update in the first week of 2015 discussing the floated slab ceiling, but, it seems as though it got eaten up? Anyway, below is another pic of the floated ceiling. Essentially, it consists Bondek (http://www.lysaght.com/product/lysaght-bondek), re-enforcing and concrete that was formed up prior to pouring. The concrete and Bondek form a single composite layer and the Bondek was supported from beneath with supports and formwork. The earlier pics show the re-enforcing and formwork from the outside and the pic below shows the metal bondek and supports from underneath prior to the slab being poured. The next picture shows the house progress as of the end of January 2015. The frame is up and the roof trusses are being delivered tomorrow. But, it has been wet for the last few weeks so progress has been slow. We are still hoping that we might be in toward the end of April. Once we are in I'll turn my attention to fitting out my little studio. Regarding the studio, over the last few weeks I decide to redraw a more accurate SketchUp file from scratch. This one is to scale give or take one or two millimetres. I have placed the Sketchup file in my Dropbox account and linked to it if anyone would like to look. If the link dies at some point please contact me and I'd be happy to share it. It is about 28.5MB https://www.dropbox.com/s/uqu9lcbfo56n03q/Latest%20studio.skp?dl=0 Stuart I was hoping to ask a few questions if I may. As you can see in the below images I am hoping to place my silencer boxes outside my outer leaf so that I can maximise my finished ceiling height. As before, one duct run will be active stale air out and the other passive fresh air in. But, I'm wondering: 1. Can I have HVAC duct runs that are after the silencer boxes and that are between 2-5 metres long. In other words, assuming the silencer boxes work correctly does it matter how long the duct run is after them, i.e., on the other side of the fan/outside world? 2. I am also showing Y branches in the two ducting runs. I hope this will be possible and will be talking to a local ventilation specialist shortly to check if this will be possible, i.e., that the Y branch will still allow for the desired air exchange between both rooms provided the extraction fan is powerful enough. If not I will run separate ducting to each each room, i.e., four independent runs instead of two linked runs. 3. Also what is the join between the ducting and the fresh air in register called that allows the ducting circumference to slowly expand to make sure that the fresh air is as slow as possible as it enters the room? If such a join does not exist I assume something has to be built and was wondering if anyone can post a plan that they have successfully used? I am aiming to use 4" (100mm) insulated ducting to and from all registers to maximise the amount of finished height in the room. So my understanding is that ideally this 100mm circumference should, as slowly as possible, open up to at least 200mm prior to exiting the air register and entering the room. Is that correct? Also is this expansion only true for the fresh air in duct runs and not the stale air out? I am assuming so. Also as depicted below I am hoping to minimise early reflections and have read a reasonable amount of RFZ posts on the forums. Please also note that I have opted for a flat internal ceiling and will add a ceiling cloud as a peaked and/or slanted ceiling will be too difficult to build now that the outer leaf is in place and also given the amount of height available. The air gap above and around all sides of the inner leaf build will remain at the initial 100mm. So along with the re-drawn SketchUp file I also created a 2D reflection map (also attached below) to help me to understand the reflections that will come from my Adam A7X monitors once they are soffit mounted. They will sit about 1200mm from the floor and will not be centred within the soffit. This 2D "ray trace" only shows reflections from the left speaker (i.e. not the right that will be a mirror image) and is based on 10 degree intervals. It seems to indicate that broadband absorbers on the side walls should help to absorb reflections occurring at approx 600mm and 800mm from the listening position. With any luck the correct amount of absorption on the rear wall will minimise the reflection off the back wall that is shown cutting through the listening position at around 100mm. Note also that the CR rooms dimensions seem to indicate that the ideal listening position will be at approx 47-48% of the CR rooms length. This 2D drawing resulted in me adding two proposed 12 degree slanted broadband absorbers that will start at the end of the soffits and extend back roughly halfway down the CR walls. These will hopefully negate early reflections and provided they do I can cope with the loss of floorspace. I also aim to add a thickish (195mm) amount of treatment to the rear wall (and 20 degree bass traps) to absorb as much of the sound that hits the rear walls, again to avoid reflections. Finally I am proposing a and a ceiling cloud (also set at 12 degrees). These additions are based on the above 2D drawing, reading the forums and in particular this post where John suggests an RFZ solution for a room tat has almost identical dimensions to the CR that I will be building: http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=1636&p=11892&hilit=rfz#p11892 4. Stuart I was also wondering if the ceiling cloud should extend all the way to the front wall of the CR? and if so the slanted side walls will mean that a single rectangular cloud will not be able to extend completely out to the sides. Does this mean that the cloud should be more of a trapezium shape when looking at it from above? Also, ideally how far past the listening position should a ceiling cloud extend? Below are some further images from the updated SketchUp file. Thanks and kind regards, Ben

Hi Ben, There are a few traces going either side of the listening position, indicating that that there will be early reflections. They are from 30-40 degrees off centre where there is still significant energy, so will cause you issues with localization. I would try making the angled section shorter but at a sharper angle. It can finish a fair bit in front of the listening position and still be effective. An easier (but less aesthetically pleasing) option is just to make the side walls absorptive. Your room is too short to have a true RFZ termination, so there is no real advantage in redirecting energy to the back wall. Colm

Hi Colm, Thanks for jumping in and providing advice. It is much appreciated. As suggested I flowed shorter angled walls (50% shorter) through both my 2d reflection sketch and also SketchUp. The shortening process resulted in a steeper 20 degree angle rather than the initial 12 degrees posted above. Those pics can be seen below. This shorter design does indeed seem to indicate an improvement on the reflection front and also will increase the amount of useable space a little bit which is great. The reflection in front of the listening position went away and the other two remained much the same. I am hoping that these remaining two reflections will have a minimal impact given that the rear wall will have 195mm of absorptive treatment and also the 20 degree angled walls would also be as absorptive as possible. 1. Can I please ask you to expand your phrase "An easier (but less aesthetically pleasing) option is just to make the side walls absorptive" a little more please. To clarify at this point I am planning to build sealed (air tight) side wall absorbers as outlined by John here (http://www.johnlsayers.com/HR/index1.htm). Assuming I get them right then they should function as absorbers. So I am wondering what the "easier" option is to make the side walls absorptive and what type of construction and materials you are alluding to? Also as you pointed out this is certainly not a large space and as a result I will be using laminated glass sliding doors to maximise internal space. So, on the right wall I will source and place an acoustic curtain that can be opened and closed to help with any reflections coming from the sliding door glass. Kind regards, Ben

As suggested I flowed shorter angled walls (50% shorter) through both my 2d reflection sketch and also SketchUp. The shortening process resulted in a steeper 20 degree angle rather than the initial 12 degrees posted above.

That sounds about right. I can seldom to it with less than about 15 or 16°.

This shorter design does indeed seem to indicate an improvement on the reflection front and also will increase the amount of useable space a little bit which is great.

Aren't you glad you came here now, and listened to us? :) 8)

The reflection in front of the listening position went away and the other two remained much the same. I am hoping that these remaining two reflections will have a minimal impact given that the rear wall will have 195mm of absorptive treatment and also the 20 degree angled walls would also be as absorptive as possible.

Right. They are also at fairly large off-axis angles from the speakers, so they will be lowish frequencies, which are less ray-like than high frequencies. So it looks like your plan is coming together nicely! - Stuart -

Ben, what are you using to draw your HVAC ducting? Is that something within Sketchup? or is it an addon module?

Hi JCBigler, The ducting and registers are all from the SketchUp 3D warehouse. Rather than search within the app I found it a lot faster to find components by going directly to https://3dwarehouse.sketchup.com in my browser and searching and downloading from there. From memory I found the ducting and registers by searching for "HVAC" only. There really are a lot of components generated by users out there which I really appreciate as they help me to get to a more complete drawing much faster than if I had to draw them from scratch myself! I hope the above helps. Thanks, Ben

Hi Stuart, Thanks again! I have been learning a lot and the time to build the house is certainly providing time for my ideas and understanding of the inner leaf build to mature. Also my SketchUp ability is improving too especially compared to the day I first downloaded the app many months ago! At this point I am about 99% sure that the latest drawings of the inner leaf will be the ones that I will implement. I am happy that the shorter and steeper angles side walls will give me a bit more internal space and will also be more effective absorbers. Yes, I am well beyond pleased that I learnt about John's forum site and have benefitted infinitely from it. I tip my hat also to your extensive and timely advice both directly in my thread and also across the whole forum. In my day job (when not playing music) I do a lot of web design and development and thus have spent the odd few hours on the web. I have researched topics using forums and I can confidently say that John Sayers' Recording Studio Design Forum, its community and the wealth of expert information is beyond any other community forum that I have come across. Stackexchange's forum also comes to mind. But when it comes to a genuine, international, community based forum, focussed on a single technically advanced topic then the amount of detail, accuracy, helpfulness and timely information is second to none imho! As for the build it is progressing nicely now. There are two pics below and we are hoping that the house build will be complete in about 12 more weeks. The external cladding and external lockup should be just about done by the end of this coming working week and then the focus will turn to the internal fit out. I can't wait to get in and start preparing and rolling out my inner leaf build! It seems like it has been a long time coming, but, it is coming soon! Thanks again, Ben

really looking good there Ben :D and hey, you not only get a new studio, but you've got a new house added to it :wink:

Hi everyone, It has been a while since I posted anything. By way of an update, we are hoping that our build will be complete and we will be in 2-4 weeks. As soon as we are in I'll post some shots and start prepping and planning for the inner leaf build. It's been a long time coming! Ciao, Ben

Woo hooo!!! Ben is still alive and kicking! :thu: :yahoo: I was starting to wonder what happened to your build, so I'm REALL gald to see that it is moving forward! - Stuart -

Hi Stuart, Thanks! and yes I have been quiet for quite a few months but i'm most definitely alive and have just been going to work, saving hard and waiting until the day that we can move in and I can get cracking on the inner leaf build. I will most likely have to finish the yard over the next 2-3 months due to building code stuff/requirements before I can finish the studio. But, over this time I will be reviewing my plans, cleaning the studio space, sealing the inside of the outer leaf with a waterproofing paint product (any suggestions of what to use?), I hope to also build my silencer boxes, go back over my inner leaf materials build list, double check the HVAC requirements and the installer/supplier I have been talking to and also lock in a builder to work alongside me throughout the inner leaf build. I have a few builders in mind that I have met throughout the house build that have been very professional and easy going. Here's a pic from today. The studio is to the right of the downstairs door and the window that you can see downstairs is the outer leaf window from the final plans. Although the final part of the build has not started yet it is much closer to finishing than it was when I started this thread :roll: Cheers, Ben

I just love seeing things move forward with studios. And your place is looking quite a bit different than it did in the last photos!

sealing the inside of the outer leaf with a waterproofing paint product (any suggestions of what to use?)

Pretty much anything will do. Any good quality masonry sealant will be fine. - Stuart -

Howdy Stuart and fellow JLS studio forumists, Firstly, thanks Stuart I'll use a high quality masonry sealant that is known to be waterproof. It's been a while since my last post as the combination of work and landscaping the new house has been all consuming. On the upside this has given me the chance to think a bit more about the logistics of building the upcoming inner leaf and part of me now wishes that this was all done as part of building the house in the first place! Oh well live and learn I guess. I promise the inner leaf build is happening soon :horse: Anyway, I'm hoping to confirm that a small change to the way that I intend to build the inner leaf is ok. Given that I will be working inside a concrete bunker (concrete core filled best blocks, floated concrete slab ceiling and slab floor) I have been wondering how I can possibly build the inner leaf frames. Initially I thought I'd build one wall at a time on the floor, fix two layers of 16mm Frychek with green glue between and then stand the finished wall up one at a time to fix them to the slab. But, the long walls will be insanely heavy and I am not sure that this will be possible or practical. If I were to go this way I would have 200mm of concrete outer leaf, 100mm of air gap and then 102mm thick inner leaf (70mm studs + 2 x 16mm Frychek) built inside out with the Frychek facing the air gap. But, after reading the forums it does sound as though I could place the studs for the inner leaf inside the air gap and assuming this is ok I should be able to build a lot more easily and the overall finished dimensions of the final room will not change if I build as follows: a. Start by building an inner frame from 70mm x 35mm structural treated pine that is 30mm off the inside of the outer leaf, i.e, the inner leaf is still entirely de-coupled, both the walls and ceiling b. Once the frames are up and doors/windows are in I make sure they are all 100% sealed with acoustic caulk, run electrical, fibre and HVAC and fill the frame with mineral wool, but, I'm unsure what density I should use, more on that below in the questions list c. Next I cover the inside walls and ceiling with two layers of Frychek, separated by green glue and again careful caulk d. Once that is done I build another frame using 70mm x 35mm treated structural pine, fixed to the Frychek on the inside, fill the frame with mineral wool and cover that will material to finish By placing the inner leaf in the 100mm air gap the build would consist of 30mm air gap + 70mm frame + 32mm (2 x 16mm) Frychek + 70mm inner frame and this means that the inner leaf would be 202mm thick all up. This 202mm is exactly as thick as having a 100mm air gap + 70mm studs and 32mm of Frychek built inside out. So no loss of space inside the finished room and no need to stand heavy walls up. Plus there is the added bonus that HVAC, electrical and fibre runs can be done prior to the Frychek being added to the bit of the frame sitting in the air gap. But, I do have a few questions: 1. Is this approach ok? I understand that I would have to spend extra money on extra wood and most likely extra acoustic caulk too. I can live with that if the build is easier. But, I am a bit worried that the isolation will be compromised/worse than having a definitive 100mm air gap? Then again is the air gap measured as the distance form the inside of the outer leaf to the next consistently solid surface which would be the Frychek that makes up the outside of the inner leaf (i.e., the extra framing that is in the air gap is being dismissed in this assumption). 2. Is there any point in filling the studs that are sitting in the air gap with mineral wool? Will I get improved isolation by doing this? And if so what density should this mineral wool be to maximise isolation? Note that I if I place wool the first 100mm inside the outer leaf to improve isolation then I am planning to only be placing it in the 70mm studs so the last 30mm to the inside of the outer leaf would be all air to avoid any chance of bridging between the inner and outer leaf. 3. To avoid losing any finished length in the CR the wall that has the door to the LR would only be 102mm thick as seen in the attached pics. You will note that all the other inner leaf walls (and the ceiling that can't be seen) would use this 32mm of Frychek sandwiched between 70mm studs. Is this ok? It is this above approach that can be seen in the SketchUp pics below that hopefully represent the final plan. Note the 32mm of Frycheck sandwiched between 70mm studs and this composite inner-leaf is still sitting 30mm off the outer leaf so the two inner rooms are 100% de-coupled still: At this point I am cleaning up the space downstairs and preparing to seal and with any luck will start building in Jan - Feb 2016.

But, the long walls will be insanely heavy and I am not sure that this will be possible or practical.

Then do it in manageable sections! :) Instead of trying to raise the entire wall all at once, build it in several smaller sections, one at a time, and raise them, one at a time, then bolt the sections together through the framing (with caulk spread on the mating faces, to get a good seal). Done! :)

it does sound as though I could place the studs for the inner leaf inside the air gap

Yes, you could do it that way too. That's called "conventional construction", as opposed to "inside-out construction". The down side to doing it this way is that you then lose additional space inside the studio, because you have to hang acoustic treatment panels on top of the drywall, rather than having than having them built into the wall itself. Since those panels are thick, they take up a lot of space, poking out into the room.... but if you don't mind having that, then you can certainly build conventionally.

Start by building and inner frame from 70mm x 35mm

I would go for something more substantial than that: 90x40 would be better.

Is there any point in filling the studs that are sitting in the air gap with mineral wool? Will I get improved isolation by doing this?

Oh absolutely! For certain! Definitely! and also !Yes! It's not a matter of if you !should" do that: it's a matter of you MUST do that. You unquestionably must have insulation in the air cavity, as thick as possible, and ideally filling the entire cavity. The insulation is part of the isolation system: It damps resonances inside the wall cavity. Leaving that out could cost you anywhere up to 16 dB of isolation... Regardless of whether you build your walls conventionally or inside-out, the cavity MUST have insulation in it.

And if so what density should this mineral wool be to maximise isolation?

For the cavity, you need a density of around 30 kg/m3 if you are using fiberglass insulation, or about 50 kg/m3 if you are using mineral wool.

I am planning to only be placing it in the 70mm studs so the last 30mm to the inside of the outer leaf would be all air to avoid any chance of bridging between the inner and outer leaf.

Go the full depth of the cavity: you won't be bridging it if you put 100mm of wool in a 100mm cavity. You'd only bridge it if you stuff it in very tightly, but just laying it in to the correct depth won't be a problem, and WILL be a benefit. I did notice that on your design yo are planning to have the rear center wall done as a slot wall: I would not do that. Too much chance that you'd end up with reflections doing nasty things back there. Another thing I noticed is that the desk is not centered: That could potentially create issues with room symmetry, stereo imaging, soundstage..... I'd center it, to be safe. I also don't understand why you have TWO frames around the room now ? :shock: :?: What is the purpose of the second frame??? - Stuart -

Then do it in manageable sections! :) Instead of trying to raise the entire wall all at once, build it in several smaller sections, one at a time, and raise them, one at a time, then bolt the sections together through the framing (with caulk spread on the mating faces, to get a good seal). Done! :)

Yes I understand, but, I was hoping to lay the 2 layers of Frychek so no joins lined up. Between each small section there will be a vertical join running from floor to ceiling. I would caulk this, but I am assuming that this would be a bit weaker isolation-wise than laying the layers of Frychek so that no joins line up, i.e., first layer run horizontally and the second vertically separated by green glue too of course.

Yes, you could do it that way too. That's called "conventional construction", as opposed to "inside-out construction". The down side to doing it this way is that you then lose additional space inside the studio, because you have to hang acoustic treatment panels on top of the drywall, rather than having than having them built into the wall itself. Since those panels are thick, they take up a lot of space, poking out into the room.... but if you don't mind having that, then you can certainly build conventionally.

Ok. Maybe I am missing something. Essentially the second frame you can now see is my attempt at trying to understand how a "conventional build" might look. Can I not add a second frame filled with mineral wool to act as acoustic treatment inside the final space? In other words a second "faux" frame rather than loosing space through using acoustic treatment panels that may or may not be thicker than 70mm but probably cost a lot more than 70mm wood and mineral wool? After all with an inside build it would be this framing and mineral wool (albeit covered in material) that you would see when inside the inner leaf and it is this approach that being used to facilitate absorption? So, unless I'm missing something (or am crazy!), I could change my initial 70mm frame to a 90mm frame and then build this 90mm frame first and it would sit 10mm off the inside of the outer leaf (this way the frame is in the air gap). Once the frame is up, windows and doors are also in and all has been caulked, I can then run all the ducting, power and data etc totally unobstructed. Next I fill the cavity with 100mm with 30 kg/m3 of fiberglass insulation or 50 kg/m3 of mineral wool. This layer is then covered with two sheets of green glue separated Frychek and at all stages from from through to drywall all joins get caulked. At this point I have what I assume is a "conventional inner leaf build". To complete the build I fix a second "faux" frame to the inside of the room and load this frame with absorption treatment at a density that is based on how the frequencies are behaving at that point in the build. Again unless I missing something technically or economically then this faux frame is pretty much the same depth and filled with the same treatment as an inside out build? I would then move on to building the soffits, bass traps and angled walls at this point and finish off in material/timber beading wherever mineral was showing. Assuming the above works then my thinking is that I lose no space inside the room, i.e., my calculations indicate that the interior dimensions stay the same as the load bearing frame sits in the 100mm air gap and the 32mm of drywall and 70mm "faux" frame equal the same depth that the inside-out construction would be. In other words for an inside-out build I would have 100mm air gap + 32mm drywall + 70mm studs = 202mm (or if 90mm stud then total = 222mm aka ritchie beanau's favourite number!) ... whereas for a conventional build I would have 90mm stud sitting 10mm off the inner leaf in all directions (this is the 100mm aigret space if I understand correctly) + 32mm drywall + 70mm "faux" frame = 202mm (or +20mm if the inside frame really had to be 90mm to house treatment). So if this works I get the benefit of a "beefy" thicker frame, I can run cables and duct after the 90mm frame is up without any obstruction, I can then fill the air gap cavity, I can avoid joins in drywall and I also don't have to stand up heavy nor small sections either. I hope all that makes sense. But, I am thinking that I must be missing something?

did notice that on your design yo are planning to have the rear center wall done as a slot wall: I would not do that. Too much chance that you'd end up with reflections doing nasty things back there.

Ok the rear wall will be filled with treatment only and covered with material to finish. I do a lot of web design work for a living outside of music and I could not resist seeing a different texture in the drawings so I re-used some elements from John's original file. I have read that slot resonators are tricky to tune well and I prefer simple over tricky so it is gone.

Another thing I noticed is that the desk is not centered: That could potentially create issues with room symmetry, stereo imaging, soundstage..... I'd center it, to be safe.

Yes, the desk is depicted off-centre visually, but, the chair and listening position is and it is that location that I based my initial RFZ planning on. The furniture desk that I have my eye on also has wheels so centring the actual furniture desk should be quite straight forward. The SketchUp drawing is this way as I was trying to see how much practical space could be at the side of the desk to allow gear to move between rooms. In the pic there is 1m to the right of the desk and this could increase to 1.2-1.3m if the desk was temporarily rolled all the way to left.

I also don't understand why you have TWO frames around the room now ? :shock: :?: What is the purpose of the second frame???

I hope this explained above. The second frame is what I called a "faux" frame above. Again, I must be thinking out of whack? I would not be surprised if this is case :roll: If building the inner leaf frame inside-out is the way to go, albeit in small sections, then that is what I'll do. I have attached a pic below that hopefully clarifies the inner leaf layers (90mm frame sitting within the 100mm air gap, 32mm drywall, 70mm "faux" frame) that I was thinking might work to make the build a bit easier. It is a bit hard to see but there is definitely no frame touching the outer leaf. ps ... I have cleaned out the space as of today and am vacuuming and cleaning this afternoon so I'm ready to seal the inside of the outer leaf :D Thanks yet again, Ben