Mix Room Design and Build UK

[sure90]

Hey!

I hope everyone here is healthy considering the current climate.

My wife and I have been refurbishing our 1970’s house for the last 2 years. Its now the time to start designing the studio with the intention of beginning the build once the Covid-19 lock down has been lifted.

The space destined for the studio was previously a internal double garage and was converted into a living room in the 80’s. I should note that there is a bedroom above this room.

I will be doing the majority of the design and construction work myself. However I would like the input and guidance of a professional throughout the design and build stages. How do I find someone who is amazing to chat to over email, Skype, exchanging SketchUp’s etc?

Objective
I’m a professional FOH Sound Engineer and I’m looking to build an AMAZING mix room whilst not disturbing other people in and out of the house when working late at night. I would also like the option to play a drum kit.

Location and SPL
The house is sat on a plot in-between 2 houses. The neighbour West of the studio is approx 20m away and the the neighbour East of the studio is approx 10m away.

To complete the below measurements I setup a 2x d&b E8 loudspeakers and 1x d&b E12-x sub. I run broadband pink noise at 99.5dBc inside the room.

Ambient Measurements (over 1 minute)
SPL West of the studio: 53dBc
SPL East of studio: 51dBc
SPL in bedroom above studio: 39.2dBc

Noise Measurements (over 1 minute)
SPL West of the studio 74dBc (Big Window)
SPL East of the studio 68.6dBc
SPL Bedroom above studio: 73.8dBc (A lot of resonance in the floor!)

Target reduction of leaked SPL Outside: 21dB
Target reduction of leaked SPL in above bedroom: 34.6dB

Current construction
Internal wall shared with house: 9” solid brick
External walls: 9” solid brick
Ceiling between studio and bedroom:
2x6” joists with 1/2” Plywood on bedroom floor and plasterboard and plaster on studio ceiling. The cavity is unfilled.
Studio Floor: 6” thick concrete

Dimensions
Length: 5.56m
Width: 4.7m
Height: 2.62m

Questions

Windows
There are two double glazed windows currently in the room. One of which, very large at 4.2m x 1.7m.
From an external perspective I cannot remove them. Although I am not opposed to loosing them inside.

My initial thought is to board the windows up from the inside and use a frosted film on the glass. Could this cause further resonant issues?

Doors
I’m playing with the idea of building a porch inside the entrance of the room. This would conceal the existing electrical consumer unit and make space for a heavy doors on each leaf. It also creates space for hvac silencers. Is this sensible from an acoustics perspective?


Floor
Am I right in thinking that its okay to bolt the the inner leaf framing directly to the concrete without risk of flanking?

Ceiling
Considering that the existing ceiling is an empty cavity, if I were to build my inner room in front of the existing ceiling, would that create further leafs? Do I need to remove the existing plaster board and open the cavity?

HVAC
I’m making contact with a UK company to help specify the necessary equipment. I need to figure out the design for the silencer boxes and placement.

I am planning to document the design and build process on this forum if you are interested!

Best, Jake.

[Gregwor]

Welcome and great first post!

You can see here that your room passes the 3 critical tests for your dimension ratios:

sure90 Room Modes.png

Its now the time to start designing the studio with the intention of beginning the build once the Covid-19 lock down has been lifted.

What is your budget?

However I would like the input and guidance of a professional throughout the design and build stages. How do I find someone who is amazing to chat to over email, Skype, exchanging SketchUp’s etc?

This forum is a self help place where you can probably find answers to 99% of your questions if you are willing to spend some time reading and taking notes (I find Google Drive is a great way to keep information you gather). If you want to pay someone to design your place or have a more 1 on 1 relationship, I can't stress enough that you should directly contact John Sayers via PM. If he can't do it, he will recommend someone who can. I would ignore any other people that reach out to you offering to help.

I would also like the option to play a drum kit.

Drums will hit ~110dBC. What is the loudest you would want those drums to be in the bedroom above you?

To complete the below measurements I setup a 2x d&b E8 loudspeakers and 1x d&b E12-x sub. I run broadband pink noise at 99.5dBc inside the room.

Thumbs up to the d&b rig. I have never mixed on a d&b rig that didn't slay.

2x6” joists with 1/2” Plywood on bedroom floor and plasterboard and plaster on studio ceiling. The cavity is unfilled.

I believe you're going to have to beef up the underside of that floor a LOT.

My initial thought is to board the windows up from the inside and use a frosted film on the glass. Could this cause further resonant issues?

If you put insulation in the cavity and ensure that your MSM design is not compromised, you should be fine. You may have to have a 3 leaf type design here as the existing glass may have little surface density. If this is the case, you just have to have an extra beefy "middle" leaf.

I’m playing with the idea of building a porch inside the entrance of the room. This would conceal the existing electrical consumer unit and make space for a heavy doors on each leaf. It also creates space for hvac silencers. Is this sensible from an acoustics perspective?

I totally get why you wanted to do that, however, I dislike how it eats into valuable bass trapping real estate and makes your room asymmetrical. I would toy with the idea of chopping off that entire end of your room and use it for storage and HVAC. I'm just not sure if it will make your room more of a square which is a bad idea. I'm sure some other cats will chime in with some ideas for layout as well.

Am I right in thinking that its okay to bolt the the inner leaf framing directly to the concrete without risk of flanking?

Building directly on the slab will limit your isolation to ~70dB but I'm sure that's no big deal in your situation.

Considering that the existing ceiling is an empty cavity, if I were to build my inner room in front of the existing ceiling, would that create further leafs? Do I need to remove the existing plaster board and open the cavity?

Yes, that will make a 3rd leaf. You need to remove the existing ceiling sheathing, seal and beef up the underside of the flooring above, then building your inner leaf under the joists.

I’m making contact with a UK company to help specify the necessary equipment. I need to figure out the design for the silencer boxes and placement.

I can tell you from personal experience that run of the mill HVAC people simply do not understand studio design/construction. This one is up to you/us/your designer to nail down and then you just go and buy the supplies from them. Are you thinking a ducted forced air design or a ductless mini split design?

I am planning to document the design and build process on this forum if you are interested!

It really would be a shame if you didn't! I hope you don't disappear as I'm excited to see your build come to life!

Greg

[sure90]

What is your budget?

For the build I've got £10k allocated.

This forum is a self help place where you can probably find answers to 99% of your questions if you are willing to spend some time reading and taking notes (I find Google Drive is a great way to keep information you gather). If you want to pay someone to design your place or have a more 1 on 1 relationship, I can't stress enough that you should directly contact John Sayers via PM. If he can't do it, he will recommend someone who can. I would ignore any other people that reach out to you offering to help.

This is great, and is deffo giving me the confidence to get stuck in.

Thumbs up to the d&b rig. I have never mixed on a d&b rig that didn't slay.

I believe you're going to have to beef up the underside of that floor a LOT.

Yep. I'm going to take out the existing plasterboard, and bulk out the existing plywood like this...

Screenshot 2020-04-23 at 20.56.49.png

If you put insulation in the cavity and ensure that your MSM design is not compromised, you should be fine. You may have to have a 3 leaf type design here as the existing glass may have little surface density. If this is the case, you just have to have an extra beefy "middle" leaf.

Perfect. I can do that. I will draw it up.

I totally get why you wanted to do that, however, I dislike how it eats into valuable bass trapping real estate and makes your room asymmetrical. I would toy with the idea of chopping off that entire end of your room and use it for storage and HVAC. I'm just not sure if it will make your room more of a square which is a bad idea. I'm sure some other cats will chime in with some ideas for layout as well.

This is gold! This has inspired me to play with a few ideas for layouts.

If I do something like this...

Screenshot 2020-04-24 at 20.07.42.jpg

Then I get a result like this...

Screenshot 2020-04-24 at 19.36.50.jpg

Plus buys me lots of space for my HVAC silencer boxes. I can easily hide the inner leaf boxes between leafs and the outer leaf silencers up in the ceiling of the "machine" room.

I like the idea of keeping the control room clean, getting computers etc out into the machine room. Whats the best way of routing cables between the two leafs if the floor is already a concrete slab?

Building directly on the slab will limit your isolation to ~70dB but I'm sure that's no big deal in your situation.

Easy.

Your MSM calculator is fantastic. Its aligning pretty well with my measurements too. I should be able to achieve my goal. I'm planning to Green Glue between every layer too.

Ceiling prediction (isolation from upstairs bedroom)

Ceiling.jpg

Wall Prediction

Walls.jpg

Code: Select all

I can tell you from personal experience that run of the mill HVAC people simply do not understand studio design/construction. This one is up to you/us/your designer to nail down and then you just go and buy the supplies from them. Are you thinking a ducted forced air design or a ductless mini split design?

Sure. I was thinking a ducted system ventilation system with a heat exchanger. Something along these lines.. https://www.vent-axia.com/range/hr100rrs

Regarding AC, I'm thinking a mini split AC system. When it comes to routing the pipes from the air handling unit to the compressor/condenser externally.. how do I avoid loss of MSM integrity?

Thank you for the help! I'm working on my SketchUp. I will start sharing if the consensus is that the above layout is sensible!

[DanDan]

Hi 90. The budget will determine what level of Acoustician. (I'm at the low end!)
I am a Pro FOH and Recording Engineer. That website is down at the moment, so Mary Black No Frontiers would be the most UK centric thing to say.

Couple of points:-

Zoning/Planning? Will it be OK to change use of the space? Anybody could complain and shut you down if you do not have that right.
Drums are loud, and IMO numbers do not reflect that properly. Simply put though a neighbour will hear a detached drum beat at best, but often starting and stopping to get bits right or for practice.
Not musical, not easy to ignore. I play in a few bands. For home I had a few Yamaha rubber kits. (S/H great value kits)
I got fed up of the last one cramping my CR so I use Aerodrums now.

If you remove high volume late night requirements your isolation will relax a lot, this has big HVAC consequences.

I have had good success blocking off windows here with MDF. I have damped the void with fibre batt, wrapped in B&Q blackout blind material. This looks utterly 'normal' from the outside.

Modal Calculators are simplistic yokes. They presume hard boundaries, fully reflective down to LF. Concrete Brick.
Few to none include the change in acoustic dimensions which fibre treatment will cause. Sound travels much slower through fibre, so the acoustic dimensions are larger than the tape measure.
I have built a green field studio which passed all 4 qualifiers in ModeWiz. The final modal response even before treatment bore little resemblance to the predicted.

In the Prosumer context, I value LF response over any attempt at LF symmetry, which is a tad oxymoronic anyway.
There are bigger issues. e.g. We often sit a half width and half height. At least a double whammy with double nulling typically 70-80Hz.
I could make a case for the listener etc. to be offset....... HF symmetry is easy.

[sure90]

Update!

HVAC

Firstly, huge thanks to Gregwor and John Steel for their help on this subject. When it finally clicked it was like a revolution ha ha.

Silencer Positioning
The Inner leaf silencers will be mounted directly to the leaf within the cavity and green glued.

The Outer leaf silencers will be mounted directly to the outer leaf plasterboard and green-glued.

The silencers will be built with 2 layers of 18mm plywood with green glue in-between.

I’m planning to use this 25mm duct foam for the inside of the silencers:
https://www.customaudiodirect.co.uk/duc ... oam-class0

I'm planning to connect the silencers with a flexible duct connector like this... https://www.ductstore.co.uk/acatalog/Fa ... ctors.html

Vent Positioning
Outgoing stale air extraction pulled out from top right corner near mix position.

Incoming fresh air diffuser above A/C split. I’m planning to loose this ducting within the bass trapping.

HVAC Calculations
I’m planning to use a A/C split so require 30% fresh air ventilation.
Room size: 1,341.96 Cubic ft (38m3)
30% fresh air: 402.58 Cubic ft (11.4m3)
7 Air Changes Per Hour: 2,818.116 Cubic ft (79.8m3)
CFM: 46.97 (79.8m3/h)
Minimum CSA required within silencers: 0.16 ft (48.77mm)

Static Pressure
Silencers: 0.14882 .wg
Louvers and filtration 0.10 .wg
150mm Ducting 0.08 w.g
Total static pressure 0.33 .wg

I’m looking at this fan: https://www.justfans.co.uk/acoustic-box ... -1540.html

Filter for incoming incoming fresh air: https://www.justfans.co.uk/filter-box-w ... -2257.html

Inner Leaf Silencer 180mm.jpg

Inner Leaf Silencer 180mm Open.jpg

Outer Leaf Silencer 130mm.jpg

Outer Leaf Silencer 130mm Open.jpg

Doors
My plan is to build two sets of super doors. Is it over the top to screw and glue two of these together? They are 30kg solid plywood fire doors.

https://www.howdens.com/joinery/doors/h ... y-25306489

I’m on the hunt for the door seals.

Questions:

I’ve planned for 400mm centres on the studs. Is this over the top? The wall and ceiling timbers will be 2x4.

I will house my computers, monitor amps etc in the machine room. Whats the best way to route cables into the control room without ruining the isolation?
I could potentially dig out concrete in the floor and install a drain pipe.

Next up I’m going to start designing the soffits. I’m looking at soffit mounting the ATC SCM45A.

Now for some sketch up drawings… Am I on the right path?

Inner and Outer Leafs 1.jpg

Inner and Outer Leafs 2.jpg

Inner and Outer Leafs 3.jpg

Inner and Outer Leafs 4.jpg

Inner and Outer Leafs 5.jpg

Inner and Outer Leafs - Ceiling Detail 1.jpg

Inner and Outer Leafs - Ceiling Detail 2.jpg

[Paulus87]

Hi,

It looks good so far, I would make your door framing a lot more beefy, especially if you're going to have 60kg+ doors hanging from them. Use 2 king studs, 1 jack stud each side and make the header bigger, maybe 2x 6x2 with a thin ply packer between. Also, use horizontal cripples either side of the door framing - 2 on the left evenly spaced and then just 1 on the right below your silencer box.

Eventhough you're planning to go 400mm OC for your ceiling joists, I would still use at least 6x2, 8x2 if you can. You can use the depth of the joists as part of an inside out ceiling if you're worried about losing height. That way you maintain your maximum height and you have a nice lot of depth for your treatment, without needing to add lots of extra framing. 2 birds, 1 stone...

I would also make your framing at the corners more solid, bolt the two end 4x2 of each frame together. You can use fat structural timber screws.

Your ventilation box locations look fine and should work fine like that, but Is there a reason you need to use ducting for your ventilation at all? I don't know what's on the other side of your external walls but with a bit of fiddling around it looks like you could just move your inlet silencer boxers to just above the mini split on the rear wall. Maybe your outer leaf box could go on the outside of the external wall and the inner leaf box could go in between your ceiling joists. Depending on what's on the other side of the front end of the room, you could do something similar with the outlet boxes. It would save messing around with lots of ducting.

Also, it's not clear in the image so sorry if this is already the case, but make sure there is a little overlap of your baffles inside your silencer boxes, so there is not a direct path straight through the box.

Other than that, looks like it's going to be a nice straight forward build.

Paul

[John Steel]

Great to see your progress and enthusiasm Jake!

My plan is to build two sets of super doors. Is it over the top to screw and glue two of these together? They are 30kg solid plywood fire doors.

Do you actually need that much mass in the doors? A 44mm solid core door blank has a surface density of approx 25 - 28 kg/m2 give or take and looking at your T/L goals I'd be surprised if you'd need to double up. Unless I've missed something, your doors only need to match the surface density of the partition that you're going to block up your window with. The door needs to be double or triple sealed in order to make it air tight, but I'm sure you know that already! Following this with interest - go for it Jake.

[Gregwor]

make sure there is a little overlap of your baffles inside your silencer boxes, so there is not a direct path straight through the box.

Yes, your baffles look a little short. They should overlap one another.

The silencers will be built with 2 layers of 18mm plywood with green glue in-between.

There is a problem I'm seeing with your silencers. You don't have "sleeves" on them to penetrate through the leaf sheathing. Feel free to use duct work to route the air wherever you need it but you should have a square or rectangular wooden sleeve that punches through the sheathing and then your duct work can connect to that.

lastly, in order to obtain our desired low velocity air, the cross sectional area of your sleeve that I mentioned above, along with any duct work run inside of your room, needs to be the same (or bigger) cross sectional area of the path inside your silencer box. That was the one calculation I didn't see you document (air velocity).

I'm glad to see your progress and excitement. You're doing great

Greg

[sure90]

Hey, sorry for the delay in my responses. I've been drawing the suggested changes.

It looks good so far, I would make your door framing a lot more beefy, especially if you're going to have 60kg+ doors hanging from them. Use 2 king studs, 1 jack stud each side and make the header bigger, maybe 2x 6x2 with a thin ply packer between. Also, use horizontal cripples either side of the door framing - 2 on the left evenly spaced and then just 1 on the right below your silencer box.

I've since done some more reading on framing. I forgot to add the noggins to my drawing.

Inner Leaf Door Frame.jpg

Outer Leaf Door Frame.jpg

Eventhough you're planning to go 400mm OC for your ceiling joists, I would still use at least 6x2, 8x2 if you can. You can use the depth of the joists as part of an inside out ceiling if you're worried about losing height. That way you maintain your maximum height and you have a nice lot of depth for your treatment, without needing to add lots of extra framing. 2 birds, 1 stone...

I was back and forth about using 6x2. You are right. I'm still achieving a 2.44m ceiling height. (I need to add noggins to the joists too)

Ceiling Joist.jpg

I would also make your framing at the corners more solid, bolt the two end 4x2 of each frame together. You can use fat structural timber screws.

I was planning to bolt the inner leaf frames together and into the concrete slab floor.

Your ventilation box locations look fine and should work fine like that, but Is there a reason you need to use ducting for your ventilation at all? I don't know what's on the other side of your external walls but with a bit of fiddling around it looks like you could just move your inlet silencer boxers to just above the mini split on the rear wall. Maybe your outer leaf box could go on the outside of the external wall and the inner leaf box could go in between your ceiling joists. Depending on what's on the other side of the front end of the room, you could do something similar with the outlet boxes. It would save messing around with lots of ducting.

The back wall of the studio is not external. It backs onto the house. See below for my latest idea...

Also, it's not clear in the image so sorry if this is already the case, but make sure there is a little overlap of your baffles inside your silencer boxes, so there is not a direct path straight through the box.

I've redesigned them following Gregwors design.

Silencer Inside.jpg

Silencer Lid.jpg

Other than that, looks like it's going to be a nice straight forward build.

Thank you!

Do you actually need that much mass in the doors? A 44mm solid core door blank has a surface density of approx 25 - 28 kg/m2 give or take and looking at your T/L goals I'd be surprised if you'd need to double up. Unless I've missed something, your doors only need to match the surface density of the partition that you're going to block up your window with. The door needs to be double or triple sealed in order to make it air tight

You are right. One solid 44mm door per leaf will be ample.

There is a problem I'm seeing with your silencers. You don't have "sleeves" on them to penetrate through the leaf sheathing. Feel free to use duct work to route the air wherever you need it but you should have a square or rectangular wooden sleeve that punches through the sheathing and then your duct work can connect to that.

Ah yes! Very good flag.

Silencer Sleeve Inside Leaf.jpg

Silencer Sleeve Sleeves Coupled With Rubber.jpg

lastly, in order to obtain our desired low velocity air, the cross sectional area of your sleeve that I mentioned above, along with any duct work run inside of your room, needs to be the same (or bigger) cross sectional area of the path inside your silencer box. That was the one calculation I didn't see you document (air velocity).

What if I remove the duct work from within the room and mount the send and return diffusers on the wall. The A/C split will sit 1.37m from the fresh air diffuser.

Fresh Air to AC Split.jpg

I'm glad to see your progress and excitement. You're doing great

ha ha thank you! I'm probably going to start stripping the existing room in the next week and start ordering materials.

Few more questions

I'm still unsure about how to route cables between the control room and machine room. Whats the best way to penetrate the leafs?

I'm thinking about using 30mm MDF to build the silencers. It may seem like a silly question, but is it safe to push air through a device made from a material which contains formaldehyde?

Thank you all!

[John Steel]

Looking good Jake - nice sketchup work!

What if I remove the duct work from within the room and mount the send and return diffusers on the wall. The A/C split will sit 1.37m from the fresh air diffuser.

As I understand it, the supply register should ideally be directly above the mini-split condenser, so that the fresh air travels straight into it (most condensers have the intake along the top surface). This will mix the air as evenly as possible and help to avoid hot spots / regional variations in room temperature.

I'm still unsure about how to route cables between the control room and machine room. Whats the best way to penetrate the leafs?

I think the conventional wisdom on this amounts to using thick PVC cable conduit and bending it into an 'S' shape using a blow torch and bending spring, it's discussed in this thread on pages 6 & 7. http://johnlsayers.com/phpBB2/viewtopi ... t&start=75
As for the safety of formaldehyde content in MDF, I can't pretend to know enough about this to give a definitive answer, but your silencers will be lined with a class 'o' insulation foam which is designed to (amongst other things) remain inert and not react with gasses. I hope more experienced members will have some thoughts on this but if it was a common problem I'm sure someone here would have heard of it by now.
ATB John.