Ground Up Home Studio London Construction Thread

Ok so I've been working away juggling studio building with normal music work and holidays and made some progress!! I've painted all the walls and most of the ceiling to seal it and at this point decided against adding anything extra to the internal ceiling. I've still got some holes to fill but the timing of my friends availability to help framing has put the order of everything out a little, not ideal but should be fine (just means filling holes over the top of the wall plates before the joists go in). I've fitted the door although it still not finished as I've got to paint everything before fixing the stops and seals (its all been test fitted though). Turns out the super door is stupidly heavy!!!! My outer door is a 54mm solid core door with hardwood lipping to which I've added a layer of 18mm MDF with hardwood lipping which is then covered with lead sheet and finished with 9mm exterior plywood (its an exterior door). I got two drummer mates over to help fitting and its has super tricky but we got there in the end! I built a dolly/trolly at the correct height of the door frame so we could slide the door from the workbench onto the trolley and into the frame...That was easy but getting the hinges all at the correct height with approx 140KG to contend with was not!!!! I think a car jack might help next time. I routed in some grooves on the front of the door which has added a little detail and smartened it up a touch, in general the door isn't perfect but its solid, opens and closes well and should do its job! The framing has started and I've now got four almost finished walls! I hired a Paslode nail gun and got busy on new years day fitting the door and starting building. Next week I'm finishing all the little jobs and painting I have to do before getting the joists and starting putting in the cavity insulation. My current aim is get the walls fully plasterboarded by around Jan 25th. HVAC is well and truly on my mind and I've got a guy who is going to install a Mitsubishi Split system and I'm just figuring out my silencers for fresh air intake and exhaust now! ( I did a long reply to the last post on this thread which I lost!).

Some pics!

And some more

Last couple

Thanks for looking and please chip in with any thoughts! I'm working super hard on this and haven't got much time to post on here but will definitely try and update more regularly...its all a little full on but I'm actually enjoying most of it. Once I've got the door and frame finished and finally fitted the seals I'll be happier to proceed with everything else knowing the shell is airtight and doing its job well!

It's starting to look pretty good in there! Nice work

Turns out the super door is stupidly heavy!!!!

Yup! :) Mass is your friend, for isolation. You have high mass in your walls, so you will need it in your door to, to keep your isolation up to a good level. Just one comment about the hinges: Are you sure those are up to the task? You seem to have four hinges on there. Each has four screws. The door weighs 180 kg. That means each screw is supporting 11kg. That's not a light load. Have you considered adding a couple more hinges? Since you already have the door completely mounted, doing that and keeping the, aligned won't be too much of a problem. Also, are those screws long, and driven deep? It might all seem fine now, but after being opened and closed a few hundred times that door might start sagging, or pulling the hinge screws out, which would trash your seals and your isolation.

I hired a Paslode nail gun and got busy

Very smart move! Things go a lot quicker like that.

I'm working super hard on this and haven't got much time to post on here but will definitely try and update more regularly...

And your hard work shows! It's coming together nicely. I'm following your thread, actually, but not commenting much because you seem to be doing fine! I usually only comment on threads when I see something that catches my attention (like your hinges), or to answer a specific question, but otherwise I just enjoy following along, and seeing beautiful progress! :thu: - Stuart -

Thanks for the advice!! I've added some extra hinges although I think the ones I originally used were fine no point it risking it! January wasn't so productive building wise but I'm back on it now until the wife goes into labour (any day now!). I've managed to finish sealing the shell with liberal amounts of silicone and more paint (mainly on the block and beam roof internally) and I've just fitted the noggins and put the joists up (not fixed yet as there a little damp). Now that I've effectively finished the outer shell I've done some very basic testing of the soundproofing for the outer leaf. The window and walls are performing well (25mm laminated glass) and the door is good but I've got a feeling the seals could be a little better. My rudimental testing method is simply to turn my boombox up full and measure at 1m inside with my phone app and then again outside by the door. I know the boombox can't create any real lowend and the phone is also not ideal but at this point its better than nothing! With the SPL of the boombox around 95dB SPL inside the outside measurements don't go above the relatively high ambient noise measured at 50dB SPL. The door seems to have more high frequency sound escaping compared to the window but still is attenuating massively. I'm super pleased but feel I can still squeeze more from the door. At this stage I'm not sure if further testing is required as I'm not going to do anything more to soundproof the outer shell (apart from tweak the door). I'm now about to add external connections which consist of one main entry/exit hole for power (including cicuits for external ventilation fans), one hole for AC, one hole for external audio connections and another for the sump pump/external light. I know this is more than recommended but I need to build redundancy into the building. My plan is seal the holes with putty like this: https://www.firesealsdirect.co.uk/non-setting-putty.html I've seen other people use rubber pads as well, any further recommendations? I'm now also considering the internal wall assembly. The leafs will consist of: 215mm dense concrete block, rendered externally painted internally. (already complete) 50mm gap 150mm stud (2x6) infilled with 150mm low density loft insulation roll. http://www.knaufinsulation.co.uk/media/809656/datasheet-earthwool-loft-roll-44.pdf Vapour barrier 2x 15mm Soundblock plasterboard http://www.builderdepot.co.uk/british-gypsum-soundbloc-tapered-edge-15mm-x-1200mm-x-2700mm.html Inner window 25mm laminated glass Inner door - superdoor maybe without lead (approx 100kg) I'd always planned on using Green Glue but budget wise things are getting tight and I'm really not convinced I need it. My aim is to achieve a TL of 55dB. I've measured a background ambience of 40dB SPL by my house very late at night and my speakers are capable of an ear splitting 115dB SPL. The studio building is approx 14m from the nearest house. I'd like to be able to play music at whatever level I like at whatever time (I generally work very quietly though!). Am I ok with this configuration if I get everything well sealed and working properly? I'm really after a little reassurance as I feel like I'm getting down to the nitty gritty (hoping to plasterboard towards the end of the week). Thanks for looking and I'll definitely upload a load more photos soon and add some more info regarding my plans for ventilation.

Ok so some more pictures! Including sealing the shell, the joists in place, infilled with fluffy insulation, AC first fix, ventilation holes drilled, vapour barrier and plasterboard!

And some more!

Sealing some holes with foam tape and acoustic/fire putty.

Here is the Hilti vacuumed onto the wall drilling two 160mm holes for the ventilation! I've chosen to place the silencers behind the speaker wall in the control room so the holes for the ventilation penetrations are close together but they're intakes/exhaust points will be separated sufficiently inside and out. I had the option to put one of the internal silencers in the rear bass trap but decided to maintain the volume of the bass trap and use up the wasted space behind the speaker wall. The ventilation will consist of two 150mm external CAB fans (200cfm) which I've calculated should provide around 7 full changes of air per hour with a velocity of under 300 FPM. The internal silencers will increase the ducting capacity from 150mm to 300mm. The space behind the speaker wall is very tight but I've managed to fit it all in in Sketchup! The grilles will be placed on opposite sides of the speaker walls (approx 3m apart).

Got some plasterboard up yesterday (Mark in the picture is my engineer friend helping me), all went in really well although the large sheets are a huge pain! I'm cutting the plasterboard with the Festool track saw and its super easy and accurate (my experiences of plasterboard before have been hit and miss!!). I'm waiting to get the electric first fix I've done signed off before moving on with the rest of the first layer of plasterboard. Made lots of progress in the last few weeks but going to slow down again as my wife is now 9 months pregnant and could go into labour any time! I have a few questions: Can I use basic plastic ducting to go through the hole in the wall (not flexible acoustic ducting) so I can maintain a duct size of 150mm? The flexible acoustic duct has an OD of over 160mm (couldn't drill a larger hole!) but the basic plastic ducting will fit. Will using the non acoustic ducting have much effect on isolation if its just in the space between the two walls? I'm planning on using a flexible duct connector to prevent bridging the two leafs. Again can I use basic plastic ducting going through the plasterboard leaf to link into the internal silencers?

Am I ok with this configuration if I get everything well sealed and working properly?

I think you should be good with that. Theoretically, it will give you what you are looking for.

my speakers are capable of an ear splitting 115dB SPL.

Here's hoping you won't be running them at anything near that level! Your studio should be calibrated for 85 dB, and that's the level that most people mix at, or lower, wit occasional boosts to maybe 100 dB for checking some aspects of the mix.

Ok so some more pictures! Including sealing the shell, the joists in place, infilled with fluffy insulation,

It all looks good to me, so far.

I've chosen to place the silencers behind the speaker wall

Hmmmm.... do you have a diagram of hos that is going to work? How are you going to run the ducts from those holes to the places they need to be?

and use up the wasted space behind the speaker wall.

What "wasted space"? That's a little curious... normally, the space inside soffits is used for bass trapping, and also for the actual speaker enclosure. More details, please.... This is the first thing I've seen in your build that has me concerned...

The ventilation will consist of two 150mm external CAB fans

Why two? Is one alone not capable of carrying the load? Or are you talking about one on the supply duct and one on the exhaust? If that's the case, then you can skip one of those. Trying to load balance those to fans would not be fun, and you don't need two anyway: just put one on the exhaust duct, to suck the stale air out of the room. The pressure differential will automatically draw the same amount of fresh air in through the other duct.

I've calculated should provide around 7 full changes of air per hour with a velocity of under 300 FPM. The internal silencers will increase the ducting capacity from 150mm to 300mm.

Sounds good. Is your 300 FPM speed for the air in the 150mm duct, or the 300mm duct? How mig are your registers (open area)?

The grilles will be placed on opposite sides of the speaker walls (approx 3m apart).

So how are you going to get air to circulate through the rear end of the room?

Can I use basic plastic ducting to go through the hole in the wall (not flexible acoustic ducting) so I can maintain a duct size of 150mm?

I would not use plastic. Use either flexduct, or round metal duct. You could use a length of 150mm metal duct for that penetration. After all, it is only connecting the two silencer boxes. But you should use a canvas sleeve or other method for decoupling the duct from the box at one end. You cannot have any solid connection between the leaves.

Will using the non acoustic ducting have much effect on isolation if its just in the space between the two walls?

Hmmmm..... sounds curious... I though you were talking about linking the outer-leaf silencer box to the inner-leaf silencer box.... Is that not what you are talking about? Confused.....

Again can I use basic plastic ducting going through the plasterboard leaf to link into the internal silencers?

OK, so it sounds like we are on the same page... The thing you need to look out for is to make sure that there are no hard mechanical connections between the leaves. Metal duct (or plastic duct) would create such a link, so you do need to decouple one end of that duct with a suitable resilient material. Canvas sleeves are common on HVAC systems for that purpose, usually between the AHU and the main duct, but you can get smaller ones too. Or you could use a short length of flex duct to accomplish the same thing. Provided that it is long enough to do a good job of decoupling, you could do that. - Stuart -

Ok so my design of the speaker wall/soffit doesn't include bass trapping. I thought long and hard about the design of the this aspect and I concluded that I'd like to use the space behind the speaker wall as a small machine room (one side of the speaker and the other side will be a small cupboard for leads and stuff, these will be accessed by small heavy well sealed doors. Behind the speakers I'm planning on putting the silencers for both intake/exhaust. Construction for the speaker wall will be two layers of 15mm plasterboard, one layer of 25m MDF and an 18mm layer of plywood on a 2x4 frame (with doors matching in mass). The voids left behind the speakers will be filled with fluffy insulation of some kind (to prevent any resonance in the cavity). The speakers will sit on isolation springs by AMC calculated to give a system isolation of approx 5hz. My reasoning for not using this space for bass trapping is simply based on my own personnel experience of large flush mounted monitoring. All the studios I've worked in consistently that have great sounding flush mounted monitors have had a heavy sealed walls (most solid concrete or blocks) and I've never encountered a studio with bass traps behind the speakers. Two rooms in particular have always provided excellent large monitoring: https://milocostudios.com/studios/the-red-room-london/ (Recording Architecture Design) https://uk.pinterest.com/pin/49187820903016734/Music Box Studio Kentish Town (Recording Architecture Design) And also Angelic Studios https://milocostudios.com/studios/angelic-studio/intro/ (Sam Toyoshima) I also been inspired by the Northward Acoustics approach to mounting ATC monitors in glass. My understanding is a very heavy/stiff sealed wall with the speakers 'floating' is a great approach. I'm sure the method with bass traps behind the wall is also great (there are lots of very satisfied builders on here!) but I think the approach I'm taking is valid and should work out great if I build it correctly. I'm just redoing the sketchup design AGAIN so will post up some images when I've tidied it up some more and made it look pretty. In terms of ventilation the velocity figure is based on the internal stage which is calculated around 12" ducting. I definitely like the idea of one fan!! I'm guessing just using one fan will have an impact on the static pressure calculation right? I'm also looking into building a shallow and wide duct to route the exhaust duct to the rear of the room on the ceiling if you believe having both at the front is a problem? I always planned having it like this but thought placing both grilles on the speaker walls would still be ok. Its a little more work to move the exhaust to the back but I know its the best idea! Thanks for the input Stuart, much appreciated!!!

I'm guessing just using one fan will have an impact on the static pressure calculation right?

Nope! :) Total static pressure is what the fan has to fight against. It's sort of like the total resistance of the system, and is independent of the fan. When you choose the fan, you need to get one that can handle the static pressure that the system imposes on it. Hopefully, your static pressure is somewhere around 0.5 in. wg. - Stuart -

Ok so I'm back building again after the birth of my first child almost a month ago!! I have my first layer of plasterboard up!! Pictures to follow... At the moment I'm just about to tape and fill the ceiling plasterboard joints, seal all the perimeter joints after adding backer rod and mark all screw positions. The ceiling was particularly tricky and in the end I don't think my screw positions are quite careful enough so dodging them on the next layer is going to be a laborious task of marking each position. I can't wait to over this stage... The fresh air ducting is in and I managed to get it nice and snug in the holes through the walls using some left over self adhesive neoprene strips. I've used canvas sections to decouple the two leafs and they seem to perform as required so I'm happy with that particular challenge! I've not done any other calculations regarding fans and static pressure. If I just use one fan do I need to calculate the static pressure of both ducts and the entire control room? Figuring out the ventilation calculations seems more straightforward if using two fans but I'm interested to use just one! I'm just looking at design of the ventilation silencers at the moment, I've seen loads online which use a single layer of OSB or Plywood. I was under the impression that the box should be more substantial (like everything else!). I'm planning on building the internal ones with an outer layer of 18mm MDF (constructed using pocket hole screws) and then lining the box with 15mm plasterboard left over from the walls and glueing it together with the correct volume and necessary acoustic labyrinth and lining. How does that sound, something similar to this... https://www.gearslutz.com/board/attachments/studio-building-acoustics/254642d1316678134-hvac-baffle-box-silencer-hvac_decoupling.png I'm reworking my Sketchup model but rather short of time with changing nappies, building a studio and trying to work as well!!

Ventilation Details

More ventilation

Bad picture of first plasterboard layer!! Ready for some joint filling, backer rod and acoustic sealant!!

So, bukarin, how is it going? This threat is very interesting. Any update? Cheers

Hey!! The update is I really really need to do an update of this thread!!!! I'm in the studio working with the speakers flush mounted on springs, incredible isolation and brilliant quiet ventilation!! Few small teething problems to resolve and cosmetic finishing to do but been super busy making music. I'm looking to get the studio finished before xmas. I've got a ton of photos to upload as well as the test data for the room. So far the bottom end is within approx +/- 5dB from 32Hz to 150Hz with a very controlled decay of around 300ms. I'll be back!!

with the speakers flush mounted on springs, incredible isolation and brilliant quiet ventilation!!

Excellent! That's great news! I'm really glad to hear that it's all working out for you, and I'm dying to see those photos! :) (and also the REW data!)

So far the bottom end is within approx +/- 5dB from 32Hz to 150Hz with a very controlled decay of around 300ms.

For a home studio, that's REALLY good. Congratulations! - Stuart -