So with all that out of the way, onwards to the future plans. We have an attached double garage, mainly single skin brick with a flat roof which was ripe for conversion. We decided to convert the garage and move all my AV equipment and study ‘stuff’ in there, and with that we would gain some more usable space in the house. Therefore the ‘lounge’ will become a proper lounge without a huge oversized set-up. We have now had planning permission granted to extend into the attic, and also to increase the ground floor, but we will probably do that in a couple of year’s time. Until then, we are converting the garage space.
THE PLAN.
I intend to keep using my current equipment which is all a few years old now. I intend to upgrade to 4K, and Atmos/DTS:X in the near future so will wire up for that eventuality. Therefore it all has to fit in the new conversion, as well as a study!
Room:
I will be converting the garage to a full ‘room in a room’ construction to maximise sound isolation. This will be done by the builders who have been working here for awhile on other projects so they know what I am like! This conversion will be complicated enough for me to understand so having people who are willing to listen to what is needed and learn how to do things will be a bonus. I know it’s impossible to fully ‘soundproof’ a room, and that it is best to think of it as isolation, and that this seems to be the best way to obtain the most isolation. I have done a lot of research into this over the last year or two planning it all so it gets done properly. There is a book by Rod Gervais called ‘Home Recording Studio, Build It Like The Pros’ which seems to be the bible on this sort of stuff which has been a major help. Other sites like thesoundproofingcompany.com and AVSforum in the USA have been a treasure trove of info, as well as gearslutz and johnlsayers which is mainly about studio building. The same principles apply if you are trying to build a home cinema to contain sound, and to also keep the outside world out too.
The garage is just over 5m x 5m and is currently attached to the house on the side, with a utility room extension directly behind it. The utility built about a year ago, but it is still ongoing, we just need to get it tiled and kitted out. The access to the garage is through here. The part of the house the garage is attached to on the side is our bedroom, so this will be the main reason to keep it a sound isolated as possible from this room.
A ‘room in a room’ construction basically means new ‘inner walls’ and a totally independent ceiling all within the garage itself. This will be totally decoupled from the original garage walls and roof. The idea is that a 2-leaf system will be in play here with the original wall the outer leaf, and the new independent wall inside, the inner leaf. The idea is that you have a MASS-SPRING-MASS system. The mass will be the original brick layer outer skin as the outer leaf, and then the new inner layer of OSB/plasterboard as the inner leaf. The spring part is the air gap between the 2 layers. The larger the better, within reason! This gap will be filled with some Rockwool RWA45, which is 45kg/m2 in density. You can go higher but I have read that this is best for low frequency isolation.
Soundproof wall pic I found online and plan to base room on:
The single skin wall is brick which we will batten out with 25mm studs on DPC strips. Then we will have a breather membrane (Tyvek Supro) attached to the studs all round the walls. The floor will have a DPC sheet laid on it as it is just a concrete base, and then the new walls/floor will go on this. Next to the breather membrane we will build a frame out of 4x2’s just so we can fit the 100mm Rockwool insulation. Then I plan to have a1-2” gap, and then build another stud frame with 4x2’s for the inner leaf. This frame will be as decoupled as possible from the outer leaf, and will form the shell of the room. Then we will layer on a vapour barrier (Dupont Airguard) around the walls and ceiling. This will enable the room to breathe, while being totally air sealed.
Then we will be planning on using 1 layer of 22mm OSB, and then 2 layers of 15mm plasterboard for the walls and ceiling. I will be using a sound dampening compound called Green Glue between the layers on the walls and ceiling. Green Glue isn’t a glue, it’s there to attenuate and damp the vibrations as the sound travels through the wall layers. It is best to use 2 tubes per sheet of material/plasterboard, but as I am doing 3 layers, I have read that 1 tube per sheet is best, as it will be used on 2 layers etc. This is hopefully going to be right as it will be very expensive otherwise as Green Glue costs quite a bit! One layer will go on, with a 1/4 “ gap around the edges connecting to the floor and ceiling, and the corners. This will be filled with a 10mm foam backer rod and then sealed with acoustic caulk. The idea is that the walls don’t really touch the ceiling or floor and vice versa. This will be done for all 3 layers.
Photo of plasterboard caulking etc:
We were going to keep the original garage flat roof but after inspection it was leaking badly, and the height was far too low. It also had a steel beam running down the middle which the joists were resting on so this needed to go. We had to change our plans and put in a new roof, which would give us a bit more headroom for the independent ceiling etc. This will be a ‘warm’ roof construction with 120mm Celotex insulation, and an EPDM waterproof covering. The EPDM will need a thin layer of plywood which is a compromise I will mention later with regards to sound isolation. The Celotex will be next to useless for sound isolation, so the ‘deck’ on the the roof joists will be beefed up. We will be having a top deck of 22mm OSB, and then 2 more layers of the same 22mm OSB in between the joists. These will all have Green Glue between, and all joints and edges will be sealed with acoustic caulk. The deck is on all new joists, which will have to be bolted/ attached via a wall-plate to the brick skin etc. We plan on using 9x3’s to span the garage. Originally we had 5x2’s but they only held up the chipboard and felt.
The new independent room ceiling joists will be running ‘in-between’ the actual roof joist to give us some headroom, but they will not touch the roof joists at all. They will be resting on the inner leaf stud frame, which will be beefed up at appropriate places. The roof joists, and ceiling joists are all going at 400mm centres, and the wall studs are going to be at 600m centres.
Pic of independent stud ceiling:
The floor will have 50mm of insulation as it’s the largest I can get away with to keep the height of the room manageable as it will be quite cramped in there once it’s all done. This will be laid on the DPM, and then I plan on 2 layers of 22mm OSB as the floor, again with Green Glue between the layers of OSB. The floor will again be kept ¼” away for the walls, the edge filled with backer rod and caulked. I am not laying down a rubber mat under the plywood as the floor will have a timber frame for the plywood to be screwed onto, so it will be coupled to the concrete floor anyway.
The whole room will be sealed at every opportunity, with any holes for cables sealed up as tightly as possible.
The doorway into the room will be a double door bank vault type construction. I plan on using a firedoor blank and then adding 2 layers of OSB to it, stepped in each time with the appropriate seals to make it as heavy as possible to help with the sound isolation. I will need to buy some norsound perimeter seals, as well as a couple of drop-down seals for the bottom of both doors. I will have one for the inner leaf, and another door for the outer leaf heading in from the utility room. This is where the walls will have to be coupled but it is only by a bit of framing to hide the gap so hopefully won’t compromise it too much.
What I plan to follow, but with 2 doors, one on each leaf:
I have had to have a window in there, first for a bit of light to the study, and also as an escape route in case of fire etc. Due to time constraints I have had to unfortunately put in a UPVC window which is rubbish for sound isolation. This is because the frame itself if hollow. We will try and fill it as much as we can, and I will aim for acoustic glass too. This is the one main compromise I think we will have, but as it is in the study area it may not be too problematic. The window looks out onto our side access with the next house over 10m away so it may be a non-issue in the end. Again we will have to couple the leaves a little here for the window reveal.
The original garage doors will be dismantled and taken away. We will block them up and make it look like there are garage doors there on the outside, so it will still look like a garage. Plan is to line the brick opening with DPC and then fit an outer stud frame that will have 3 layers of 22mm OSB with Green Glue between the layers. This will then have a breather membrane fitted on the outside with an air gap, battened out and then clad with some form of timber to resemble a garage door. Then we will basically count this as an extension of the single skin outer brick layer, and continue on the inside as with the rest of the room interior above. We might be able to fit some extra Celotex in the frame as I have some 100mm stuff left over from the utility room extension.
HVAC: With a ‘sealed’ and sound isolated room there is the small problem of getting air into the room. I have got a Daikin MHVR unit which will be mounted somewhere in the room (or outside) to provide fresh air into the room, and to extract the stale air. It is a heat recovery unit so will hopefully work well in here. The idea is that it will provide all the fresh air we will need in the room. I have made sure it will be up to the task to have enough flow and capacity to change the air in the room over 6 times an hour or so, as when the doors are shut it will be the only mode of ventilation, unless I open the window! This unit needs 8” vent piping to work, so this will eat into my room a lot so careful planning on where to position the vents will be needed. I will also need to penetrate the double wall construction for the intake and extract of air. This will of course need to be done with the minimal of bridging/coupling of the double leaf setup. My idea will be to make a couple of plywood ‘tunnels’ that go through the inner stud wall and then sit on the brick outer wall. They will be heavy in themselves so they will need supporting, and once they are ‘in the room’ they will have to be connected somehow so there will be a compromise in the soundproofing efforts here too unfortunately. I will have a good think once we get to building it how this can be minimised though. I originally planned for the unit t ogo inside the room, and maybe site it behind the screen, but it really is massive so I think it will have to be enclosed outside the room. This sort of makes it easier as the baffling to contain the noise can be partially installed outside the room to save space.
Baffling pic I found online:
The AV equipment, and server PC etc will all generate a lot of heat that I hope the MVHR unit will be able to extract well enough. I am not sure it will to be honest so I am planning on adding an A/C unit, probably a split unit but haven’t fully decided yet as they are quite costly. I will need to plan ahead though as I will need to put in the pipes and cabling in early on as these will also need to breach the sound isolation too. Normally the indoor unit connects to the outdoor unit and it all looks quite neat but I need to plan where it will be sited and how it all works.
Now before you say it, yes there are some compromises in the sound isolation parts of this build. With UK construction we have cavity walls with ties and insulation, so the walls that the garage is attached to the house with will be a cavity wall. This is the rear and side aspect of the garage, the rest is single skin. This is where I will have to make do with the side effects of a ‘triple leaf’ effect, and there isn’t anything I can do about that. The roof will equally have a small triple leaf, as the uppermost layer of OSB/plywood under the rubber membrane will be the third leaf. Even the ‘fake garage doors will count towards a third leaf so another compromise. Again this is unavoidable but hopefully this will be a minor issue in the end. I am not aiming for a totally isolated room, but aiming for the best we can get considering the current building we have to work within.
Electrical Considerations: As this was the garage, originally the whole house consumer unit was here. We are planning to further extend the bungalow by building into the roof space, and rear, so thinking ahead I had the consumer unit moved into the new utility room extension. This is directly behind the garage but we had to get ALL the wiring extended from the attic space into the new extension, and also fit ALL the possible future wiring into it as well. That took a lot of planning, and I am hoping I didn’t forget anything! What this meant was that I needed power for the garage, and I am planning on a little more than just having a 32A ring main in there. While all the electrical work was being done, I ‘upgraded’ our lounge power supply where the home cinema currently resides. I had an extra feed and consumer unit moved to the other side of the house where that room is located, and where the shed is too. The ‘old’ consumer unit was placed there and then I had 3 new dedicated circuits installed just for the AV equipment. I know there is a whole sub-set of fairy talk on power supply, dedicated circuits, size of circuit, and even what cable to use but as it was relatively easy to get done I thought what the hell and whacked in 3 lots of 6mm ring mains in to the room, each on its own RCD. The electrician at this point had already thought I was mad, but now just says ‘what do you need and where!’. This leads me to the garage, I am having the tails split and having a dedicated consumer unit installed in the new room. These cables to supply it will obviously be caulked and sealed so not to ruin the soundproofing efforts elsewhere. This consumer unit will now end up supplying the AV area with it’s own dedicated circuitry, and also my study with it’s own set of circuits. I will also need power for lighting, and other things like HVAC requirements so this will be good for that too. All the electrical work will be done by the electrician so can be signed off etc.
Now onto the more interesting part as it’s about what the room will look like etc! The garage will be split into the main cinema area, an AV equipment area, and a study. I am inclined to make the study more enclosed so I can keep my computer/server noise out of the main cinema room, but will see how much of a problem it is later.
Here is photo of the layout I sketched up on paper. It’s a work in progress at the moment as lots might change but the general idea should be there.
I really want to make it a dedicated home cinema so the idea is to have it as dark as possible, but unfortunately a black ceiling and walls might not be to my wife’s tastes, so dark colours it will be. It will be dark enough though!
Equipment rack in separate area: The AV area will be where I will keep all the equipment. I plan on having it all stored in a Middle Atlantic rack, but these are expensive, so I am going to use my ‘old’ racks for now and build the opening so I can ‘upgrade’ later. These racks are open glass ones, with a metal frame that can be stacked, so will hopefully leave enough airflow around all the components. The AV stuff will be on show in the ‘foyer’ part of the room but will not be distracting or have any glare onto the screen. I will hopefully have this area closed off to avoid any noise coming out from it as I might out my server pc and/or my HTPC in there. The heat will need to be extracted somehow but it will be large enough to passively cool down some of the components. I will see what I can do with the extra run for the HVAC but it will need to be cool in there as amp and pre-pro’s tend to run hot!
Wiring: I will of course have to get all sorts of wiring in from the AV area to the stage and PJ area for speakers, amps, video, D-Box, tactile transducers and everything else that entails with this mad hobby. I have had a LOT of Cat6 cabling run from the loft already into this room to facilitate multi-room video if I go that route in the future, and for network access too. I have also run some coax for SKY/Freesat etc. Also thoguth about HDMI runs which will go into the loft in case I move some equipment up there in the future for another Node 0 area for the rest of the house when we extend. I have done as much wiring as I can think of now as when it’s in I won’t be able to add anything later due to the sound isolation construction, hope I haven’t forgotten anything!
Room size: The final home cinema part of the room will be just over 3m wide and around 5m long, and just over 2m in height, so it will be cosy in there. The length will be eaten up with the stage and screen so it will feel a lot smaller once everything is packed in there.
Screen area: I intend to upgrade my screen and go for the full AT effect with all the speakers behind it. I also want to have a TV there for an easy life when the PJ isn’t needed, so the screen will have to be a retractable one. I am moving towards a SeymourAV AT screen but haven’t bought one yet. The screen will be just under 3m wide, with a 2.35 AR as I am aiming for a CIH screen for my anamorphic lens etc.
Stage: I plan on building a raised platform/stage behind the screen for the LCR speakers, and the subs to sit on. This will have the effect of making the room look more like a dedicated room and will help with the isolation. The problem we have is that I like bass. Lots of bass. If a film has bass, I like to FEEL it. Unfortunately this is that hardest part to contain if you are truly trying to isolate a room. Once the walls and floor are done, I will have a stage constructed out of 6x2 timber (maybe 4x2?) and then it will have 2 layers of 22mm OSB with green glue between the layers as it’s top. It will be lined with plastic and filled with dry play sand. The whole stage will be sat on a rubber mat to keep it decoupled as much as possible from the floor. It will also not touch the walls either, so will be built a few inches away. This means I will have a small channel for wires/cables to run behind it too. The idea is that the subs/speakers energy will have to move all that weight/sand first before being transferred to the concrete sub base of the garage floor. Concrete is a good sound conductor so this will hopefully minimise it to some extent. I don’t envisage it stopping it all, but some reduction in the LF transfer to the rest of the house is better than nothing.
Diagram of what I intend to do with the stage or something similar:
The rear wall of the stage area will have some absorption panels on it. The retractable screen will hopefully be installed so that it drops just in front of the stage. I like the idea that all you can see is the screen, with all equipment out of sight. Hopefully with the stage the screen can drop to just around stage height and so it will block all the speakers and TV etc.
Room Acoustics: I hope to incorporate some acoustic treatment into the room, and I will be re-using some foam from the previous room etc. Once the room is built I can work on that.
Seating: I have my 2 D-Box seats, which are each 2 seaters, and they both electrically recline too. The will be placed side by side near the rear of the room. I am considering a riser for them, in case I want to put in another row for the rare occasion we have more people. I am not sure that I will have the space though, as this would mean the viewing distance becomes quite small for the front row. I will probably put in a small riser and see what fits nearer the time. I will also fill the riser with sand as I will be wiring up for some rear subs if I get some more later. The D-Box seats will need power, and also some Cat5/6 ethernet for the signal to be relayed from the HEMC processor unit.
Lighting: I have a 6 zone Lutron Grafik Eye unit I want to use, so I will wire in enough for these zones to be used. I love lighting effects and the way it can be dimmed so will have a few ‘scenes’ and zones set up for the room. Depending on final height of room I will have a soffit around the perimeter of the room to hide the downlights, and to possibly have a ropelight for extra uplighting. The size will depend on downlight depth etc. This soffit may or may not hold the ATMOS speakers, I haven’t decided on that part yet. I hope to have some lighting in the stage area too, and maybe on the riser, but we will see once the room gets nearer that time of construction.
Photo of lighting plan:
Soffit construction plan (I am not using clips but you get the idea):
Star ceiling: I am toying with the idea of one and will see if I can get one to fit. I see that you can buy them in ready-made panels and I think we may have a 2m x 3m ceiling to work with so it may work. I am planning on having power ready for it, and to build the soffit with it in mind. The bonus with a star ceiling is that I can get away with a black ceiling as that’s how they are designed and my wife actually likes the look of them which is good.
Projector: I will use my current JVC HD100 and lens as the main PJ, but I do have an Acer 3D PJ too which I will install as well. I intend to upgrade to a fancy 4K one in the future but with allthe changing standards of HDR, HLG, Dolby Vision etc I think I will wait awhile. Plus they are mega expensive at the moment. I think the JVC is absolutely brilliant and it has been in good use over time, I just changed over the bulb recently so it’s got a good lot of hours left on it just yet. I will try and see if I can build a box in the soffit for the PJ and try to hide it a little, but it may just end up being a glorified shelf. I am toying with a hush box as it does make some fan noise, but I don’t think I will have the space unfortunately. Once the room is ready I can decide on that, as it will need to be ventilated too.
Audio: I am going to wire up for ATMOS/DTS:X, and will plan on 4-6 ceiling speakers, and also wire up for wides as well as rear backs too in case I want to full monty when I upgrade my processor. At the moment the most we can have with ‘normal’ AVR’s is 4 heights, but in the future I am sure there will be provision for more. I definitely can’t afford the likes of Trinnov and Datasat but I can dream!
Video: I don’t have any 4K sources, or any way to watch them either but I am planning on upgrading at some point. I will use all my current 1080p gear for now.
List of my AV equipment going into the new room copied from my signature:
Denon AVP-A1HDA
JVC HD100 PJ with Schneider 2.35 Lens
Acer H9600BD 3D PJ with Prismasonic 2.35 Lens
8’-10' wide 2.35:1 screen planned
Lumagen Radiance XE Video Processor
Pioneer KRP-600A
D-Box seats x 2 with HEMC controller
Crowson Tactile Transducers for both seats with Crowson Amplifier
Parasound Halo JC-1 Monoblock Amplifier
Cinepro 2K63 Amplifier
Parasound Halo A23 x 2 Amplifiers
B&W 802D Mains
B&W HTM2D Centre
B&W SCMS Rears and Sides
SVS PB13Ultra x 2 Subwoofers
SVS ASEQ Subwoofer EQ
Oppo BDP93 Blu-ray player
Dune BD Prime 3
SKY HD 2Tb
Google Chromecast
Classe CDP-300 DVD/CD player
Parasound D3 DVD/CD player
PS3
XBOX 360
Nintendo Wii
HTPC with XBMC in progress!
Philips Pronto TSU9800 Remote Control
Server PC with approx 19TB storage
Mains: Isotek Titan x 2, Isotek Nova x 2, Power inspired AC regenerator AG1500 and AG500
Right, so I think that’s about it, hope I didn’t forget anything! Sorry for the long post, hope I haven’t bored you with my plans and inane ranting…….just trying to document my thoughts on here to see if it’s any help to others who might want to do a similar project.
I will post up some pics as and when they get done. Currently we are nearly done with the framing part and are nearly ready to start dividing the room up for the main room and study, and then we can start the plasterboarding. I will post up some construction pics up soon.
I am sure I will need some help from you all at some point too on how things need to be done so thanks in advance for my rants and stupid questions!
Thanks for reading this far…..
Cheers!
Ash