In earlier parts to this series I have spoken a little about acoustics but I wanted to go over the two areas that I (and others) need to cover when embarking on a studio build.
- Sound proofing - that is keeping sound out of the building to prevent audio contamination of recorded material, and keeping sound in to prevent annoying those around the studio.
- Acoustic treatment - to enable a good sounding space for good recording and mixing.
As already outlined in this episode the sound proofing consisted of a combination of various materials. The walls were made of a double skin consisting of a brick outer, a wooden stud wall, an air gap between them and then the stud was packed with Xtratherm insulation material. On top of this was placed plasterboard before plastering. The ceiling is also a wooden frame that sits on top of the stud walls and is covered in 50cm of Earthwool insulation.
The floor is a 24" bed of concrete and laid onto that is an acoustic membrane and then a solid wood floor.
The glass in the building is triple glazed and all sits in sealed aluminium frames, when out a locking mechanism creates a complete seal.
In terms of attenuation from the inside the sound from the road (which is the largest contributor of outside sound) measures from around 70-80dB to around 15-20dB. This is more than sufficient to reduce any extraneous noise coming in. Conversely when I set the volume of the studio monitoring to a volume that means no mere mortal could stay in the room for any length of time, when going outside the studio, from around 4 metres there is no evidence of sound from the building.
I'm pleased that both attenuation boxes have been ticked. The first because a studio with sound bleed coming in would be useless for any kind of tracking and secondly noise pollution is one factor that is pertinent to most planning applications, it's probably also the fastest way to upset your neighbours.
As I'm a songwriter and composer tracking in the studio is mainly limited to voice and acoustic guitar, so the space needs to work for them.
One mistake that some make about acoustic treatment in recording studios is that they think all reflections are bad, then try and create some kind of anechoic chamber to record in. OK I'm exaggerating but you get the point. Reflections aren't bad, uncontrolled reflections are the issue and those are what one is trying to deal with in a studio. You can listen to studio designer Andy Munro talking about this in our interview with him.
As the space is a mutli-purpose room, the acoustics need to work both for recording and mixing so I going to drop the C bomb - compromise. Often seen as a bad word by purists but in reality the choice for most home studio builds.
At the lounge end of the room are the pallet walls, made up of hundreds of pieces of reclaimed pallet timber and running across the full length of the end wall and one third of one of the long walls. Whilst aesthetics were a primary consideration I also asked the builder not to sand and resize them creating a large diffuser. It works well and this can be heard when recording acoustic guitar, as moving the guitar around in that space can create a lot of different results which give a nice open guitar sound with few nasty reflections. It also works well for vocal recording as well. Vocals are always recorded using the SE Reflection Filter to add an extra line of defence and this works very well.
As it's a multi-purpose space the decision was made to have the mix position firing across the room rather than down it. The room is just over 3m wide. This allows for the speakers to sit 0.5m away from the centre of the flat wall and not the corners, The mix position is about 1.5m from the rear wall and then there is a further 1.5m behind the mix position.
Acoustic treatment consists of a number of things.
- Hybracoustic SQM 1 - Acoustic panels combining the function of absorption and reflection of sound through the use of acoustic foam and the front of the plywood dispersion plate. Designed for any room where is a problem with reverb and other adverse acoustic in the medium-high frequencies.
- GIK Acoustics 242 Acoustic Panels - designed with a rigid absorptive core and are broadband meaning they deal with the entire frequency range. The 242 Acoustic Panel has a built-in air gap which not only increases low end absorption, but allows the panel to hang truly flush on the wall using an integrated wire on the back.
- GIK Acoustics 244 Bass Trap - absorbs up to 50% more low end (below 60Hz) and retains 75% more high end (from 400Hz and above) versus the broadband FULL RANGE option. This is mounted using their Cloud Mounting Brackets which provides a 4″ air gap to absorb lower frequencies.
The combination of these units creates a nice neutral sound when mixing and helps to reduce any extraneous reflections which can affect mixing. I don't mix at loud volumes which can also help in keeping reflections under control.
The final part of the acoustic treatment consists of the brilliant Sonarworks software and microphone. I used in mainly out of curiosity to see how good the room sounded and what issues there were. Set-up takes around 30 minutes and is idiot proof, the software walks you through every single step of the process. Once completed I found that the room had a couple of minor issues in the low mids and in the highs creating some issue with pan positioning when mixing. The nice thing is you can flip between the original and 'fixed' sound to hear the difference.
I'll be honest I didn't spend weeks measuring stuff and calculating the room as some might do - I'm just not bright enough for that kind of physics and I tended to know from the size of the room and the position what kind of issues would be present. I'd also been greatly encouraged by discussions I had with respected studio designers who were far more down to earth about the whole thing than you find by those who spend all day in forums giving their advice on the matter. You may want to take a more scientific approach to your design, that will of course depend on how critical you need the end result to be, as I've already stated as a multipurpose space compromises were always inevitable.
What I've ended up with is a room that sounds great when recorded and is helping me to turn out mixes that I'm getting great feedback on. I've also had several people already visit who all think the room sounds great - more of that in a later episode.
My parting advice is that with some common sense thinking about the construction, plus taking advantage of some great products now available at remarkable prices, it's not hard to build a reasonable sounding studio for recording and mixing at home.