PG Music Home Forums General Discussion Recording, Mixing, Performance and Production Seeking Room Preparation Advise

Hello all

I'm planning on converting a concrete utility room into an office for three purposes.

1. Office
2. Small workbench to fix computers
3. Recording studio.

I would like your suggestions please. The walls are double skinned breeze blocks so its very sound proof and dry but cold during winter. Heating through the winter has been a challenge. Its all concrete with a tall ceiling. I found keeping an oil radiator on constant med/low 6am-10pm warms the room up nicely but it doesn't hold the heat. I've had quotes and what's been suggested is raise the floor an inch with wood, insulate and carpet. For the walls - to fix plaster sound board 12.5mm thick but its going to make a narrow room even narrower. I need to make a decision on what to do to the walls?

1. Just paint speckled course walls + Acoustic Foam
2. Plaster walls + Acoustic Foam
3. Fix plaster sound board + Acoustic Foam

I've wondered tonight if adding acoustic foam to the walls on their own might help with heat retention as well as provide much needed acoustic treatment? What do you think?

This is my current office which I'm pulling out of to save money showing workstation size.




Utility room 5.3m length x 2m wide includes concrete shelf of 1.4m length
Sink and old kitchen top/cupboards will be removed and my desk will go on the right side of the wall where you see the washing machine and tumble dryer.

Paul, the acoustic foam will do very little to nothing for heat retention. What is on the other side of the block walls?

Gaps between solid surfaces are what help for heat retention. This is where putting up sheetrock, gypsum board, etc. (not sure what it's called in UK) with a gap between it and the block would be helpful for thermal insulation purposes.

Don't bother with the sound board if it's just the sawdust based type like they sell here in the US because it's designed to go in between relatively acoustic transparent surfaces. Here in the US it's often used between adjacent living spaces for 'stick construction'. You don't have that issue with the block walls.

That is a pretty narrow space. Monitoring using your monitors will be problematic because of the room modes that will be present at fairly significant levels due to the small size.

Type in your dimensions here to see what I'm talking about:
http://amroc.andymel.eu/?l=200&w=390&h=350&r60=0.6 I took a guess at your height, and used 390cm (didn't include the high shelf, but you can run one of these simulations adding in the additional length. That website also gives direction on absorption amounts needed to tame modes. Modal density is pretty thick with those dimensions.

I would suggest investment in some very nice monitoring headphones now and begin getting used to mixing on them in your current space.

I don't see any microphones in your current room, are you doing any mic recording? These modes will also affect recordings.

-Scott

Paul

There are two threads here that might also provide some useful information

Building Isolation booth in Home Music Studio

Best Acoustic Panels for a Home Music Studio

Thank you VideoTrack

Yes it is small but I reckon I could pull it off. The primary reason for moving office back home is to save my business money. The second is to use what I have to record again because since I've had an office across the other side of my city I've never recorded music since moving there.

You might want to investigate foam board insulation for the walls:
http://www.homedepot.com/b/Building-Materials-Insulation-Rigid-Insulation/N-5yc1vZbaxx


Foam board insulation is flammable and code here says we have to cover it. I have it in my basement and it really helped. If you also have to cover it you can use paneling. I used 1/2" (31.75mm) foam board and it worked.

For the ceiling You might want to investigate 2"x6" (50.8mm) studs, 6" (152.4mm) fiberglass insulation covered with dry wall:
http://www.homedepot.com/p/Owens-Corning-R-19-Kraft-Faced-Insulation-Continuous-Roll-15-in-x-39-2-ft-RF40/202585898

This should keep the room warmer.

FWIW I would solve the heat loss problem first then attack the acoustic problem second.

PS - I am assuming that all of the products that I mentioned are available in the UK.

Couple pics I took today to help give a sense of perspective and size. The inner walls you see are the inner of two walls with about an inch gap in between. Adding more insulation on the inside would make it very narrow I fear.

Would I be correct in saying the cold is mostly coming from the floor?

Paul what is on the other side of the walls and floor?

Paul the physics really don't support pulling it off because of where your head is relative to many of the room modes.

Do yourself a favor. Take your monitors from your current space and move them to the new room and place them where your plan shows. Take a chair and place it where you plan to sit while mixing. Play back the tones indicated by the web link I put above and rove your head in a .5m diameter and listen to the huge difference in level due to just moving your head. Start at the lowest tone and go up from there. You cannot fix those sensitivities without bass traps, which take up lots of room. Do this before you make any investment in raw construction materials and labor. Learning to monitor with headphones will be key for successful mixing in a room with these narrow dimensions.

I've looked at that weblink of yours but don't understand what I'm seeing?

http://amroc.andymel.eu/?l=530&w=200&h=300&r60=0.6

Bottom line is - this room is being converted into an office - but I will use it for mixing & recording also. So pulling it off has to be because that's where my computer will be. Because I have mixing headphones also I do have the best of both worlds surely?

Exactly what is on the other side of the three walls? Are they open to air, outside or another room, or back-filled with earth etc?

Concrete has a thermal conductivity similar to glass

W/(m K)

Concrete, dense 1.0 - 1.8
Glass, window 0.96
Plaster light 0.2
Cork, re-granulated 0.044
Styrofoam 0.033

I think you really need to make the small space sacrifice and get something on those walls, or be prepared to keep the heater running.

You'll need to do yourself a favor too with acoustics.

Paul,

The display that you see, once you type in your dimensions, are the acoustic 'modes' of the room, or in other words, the natural frequencies of the room itself. Another way to think about it is these are the standing waves that will happen in the room, unique to the dimensions of the room.

The issue you will experience is that your listening position is right in the middle of the most narrow dimension and nearly at the center of the longest dimension, where the standing waves will have a 'nodes' or points which will have very weak bass response.

The strength of acoustic cavity modes generally weakens with larger rooms and as the modes go higher in frequency.

To see nodes, look at the wikipedia article on room modes:
https://en.wikipedia.org/wiki/Room_modes

The nodes are those points where the amplitude is near zero - for the axial modes (those that look like the top picture in the article) you have a node. On the graph in the calculator website, the primary axial modes are the 32Hz - which is the primary axial mode from the long dimension (your's won't be this exactly because the high-shelf wall is not the full 530cm to the door. That primary axial mode will be somewhere between 32 Hz and 44 Hz (44 being the result if you consider the shelf not being there) and it will not be as strong. The 57 Hz mode is the floor to ceiling mode, if your ceiling is 300cm from the floor. Your listening height while sitting is probably going to be something like 125 cm or so, correct? Since you're listening height is not right at the middle, you are actually going to hear a bit of boost at 57 Hz or nearby in frequency.

But the modes between 80 and 90 Hz, the fact that there are two strong modes adjacent to each other, the first axial mode (1,0,0) of the 200 cm dimension and the 2nd axial mode (0,2,0) of the long dimension, that's going to really give you grief while monitoring and recording with a mic if you have the mic anywhere in that general vicinity of the room.

Something that you could possibly do with this room is use the 'high shelf' area for a bass trap. Many ways to go about this, but I'm thinking you might have a potential boon with this area. Several things you could try:

1. Hang a heavy curtain across the opening to the shelf area, while at the same time use open-face fiberglass batting (is this mineral-wool in the UK?) lightly stacked in the space. Use the type where the fiberglass fibers are not covered with paper or plastic.

The blanket will function as a sort of barrier that is moveable and the primarily axial modes of the long and floor-to ceiling dimensions will work against this barrier and even the oblique modes in the room will work against that curtain. The mineral wool will act as a general broad band absorber.

2. You can also do a bit more construction effort and make more of a door, hung at an angle and again using the whole space with mineral wool lightly stacked in there and get more absorption of the floor/ceiling and oblique modes. Have a google search look for home constructed bass traps for ideas.

However this is not going to fix the issue that I believe the physics to reveal as your main issue, the primary and secondary axial modes of the 200 cm dimension at 84 and roughly double that, are going to give you grief while monitoring and somewhat while recording if your sources have significant content that low.

To make it work for you, I will again suggest that you are going to have the most success learning to mix using a good set of headphones and reference recordings to compare against using those headphones.

The other issue with such small dimensions is that you will need to acoustically treat the walls that make up the small dimension otherwise comb-filtering will occur in your recordings. At least treat one wall with some acoustic wedge type material designed for acoustic treatment that is 3" deep at least.

http://www.acousticfields.com/comb-filtering-relate-room-acoustics/

Actually, you might want to spend some time on that site above - they have some decent videos that will help explain your challenges.

watch the video on that site called "Your room doesn't care what you want" to start.


-Scott