Recording Tips
SO, YOU HAVE A RENTAL PROPERTY, A SMALL SPACE, A TEMPORARY LOCATION, OR A MULTIPURPOSE ROOM THAT DOUBLES AS A MUSIC SPACE. BUT…. IT SOUNDS LESS THAN PERFECT FOR RECORDING?
Unfortunately, the expensive part of setting up a professional recording studio isn't the gear, but rather the physical space! This is especially true in today’s climate. Living spaces seem to be getting smaller, while real estate prices climb through the roof and out of everyone’s grasp. Meanwhile, recording technology is getting cheaper and far more powerful. This has given rise to a situation where there’s greater access to recording setups than ever, while there’s less and less room to work in.
However, there are many things that can be done to at least improve your working environment, sonically – even if they are temporary measures. Ideally, you'll want to spend as little money as possible and do as much as you can yourself. Also, you may want to make things portable or able to be dismantled and reinstalled somewhere else, should you ever need to move from your current location.
Obviously, most high-end studios are purpose-built from the ground up. A small fortune is usually spent on the design alone, before construction even starts. Thus, the most limiting factor of setting up a studio in any preexisting structure is that you can’t change the space’s dimensions. Doubly so if it’s not even your structure to alter!
In a perfect scenario, a recording space will have no parallel surfaces for nasty standing waves to accumulate; the room will be isolated from the outside world, both to keep certain sounds in and others out. Surfaces will be carefully chosen to minimise excessive and unbalanced frequency reflection, yet provide a natural sounding environment.
SOUNDPROOFING VS. ACOUSTIC TREATMENT
A vital starting point is to clarify the critical difference between these two terms – which, despite being related, are not interchangeable. Soundproofing refers to isolating the recording space from the outside world. Acoustic treatment, on the other hand, refers to dealing with the reflective sonic properties inside the room – walls, ceilings, floor surfaces and the like.
Soundproofing is by far the most difficult and expensive part of studio building, and even with a large budget can be very challenging. To achieve even a 50-to-60 percent reduction in sound transference is hard work. True, 100 percent soundproofing is almost impossible, unless you happen to have a vacant underground military facility at your disposal.
To even partially soundproof a room in a rental property, a lot of care would need to be taken to avoid doing damage to the property. To boot, you'd probably end up breaking a few laws and lose a whole lot of money. Still, a lot can be achieved with innovation, experimentation and lots of research.
SOUNDPROOFING
The main two issues to be dealt with are the mass and thickness of the walls, floor and ceiling, and air gaps. Thin walls and ceilings will allow sound to transfer easily in both directions. Doors and windows are also your enemies, as they do very little to keep sound in or out.
In a high-budget scenario, the best thing to do would be to build an entire room inside a room. This is not for the faint-hearted, and not a cheap or portable solution. There are several companies that market prefab soundproof booths which can be dismantled and relocated. Once again, however, they're not cheap.
A medium-budget solution is to at least improve the doors and windows to seal gaps and increase their mass.
Replacing the existing door is a great start. Most internal doors are not solid timber – they're basically a timber frame with a cardboard core, which is useless for sound isolation. Rather than potentially damaging the existing door, try your hand at building a studio door. That way, you can put the original door back on when needed.
There are lots of tutorials and door plans available online. You can often start with an existing solid-core door from any hardware shop, or source a secondhand one. In simple terms, you want to add mass to the door. Basic methods include adding a layer of gyprock or plywood to the door on the outer side. The main thing to watch is the increase in weight – you may need to consult a tradesman on what’s possible and safe.
Once you’ve improved the door itself, you'll need to make it as airtight as possible. Door and window sealant kits are readily available – often sold as weather-stripping tape. Adhesive rubber strips can be attached to the door frame to close gaps. Specially designed door sweeps – which effectively seal the gap between the door and floor in the closed position – are also available. The style you want will depend on the floor surface – carpeted floors will require a different solution to one made of
timber, for example.
Windows are even more of an issue, as most only have six millimetres of glass and lots of air gaps. As much as natural light is lovely, it's likely that a window will be the weakest point in the room. The easiest method to fix this is to simply board the window up with a sheet of heavy plywood or similar. The least damaging way to do this is by inserting the covering sheet inside the window frame and lightly tacking it into place. Seal all the gaps with weather stripping first, then place some insulation either up against the glass before you put the sheet into place, or apply it to the glass-facing side of the board. This will largely reduce rattle and movement.
You could also try mounting another sheet of framed glass up against the window frame, if you’re wanting to maintain light and/or the view. The glass used in studio windows is usually at least ten millimetres thick, and is
very heavy and pricey.
There are also companies that make inserts from glass or acrylic for this purpose, They're often known as ‘storm windows’, and are designed to make the windows airtight and reduce sound transfer by up to 50 percent. They can easily be unscrewed when not required.
WALLS
The old trick of sticking egg cartons up on the wall as ‘soundproofing’ will mostly make your room look like a chook shed! The idea comes from the concept that an uneven surface will break up sound reflections, and thus provide a less reflective environment than shiny, flat surfaces. This is true, but will not actually aid in any way towards isolating your room.
The other common scenario (and I was guilty of this myself back in my early days), is to cover every surface in commercial acoustic tiles. The result will be a highly unnatural sounding room devoid of mid/high frequencies, that sucks the life out of virtually every sound made. Acoustic treatment has to be carefully planned and balanced to achieve a natural result.
A lightweight DIY room-in-a-room is simpler than you may think, and certainly worth considering. There are various ways to do this. One of the simplest methods is construct a room out of sheets of plywood, with minimal framework – kind of like a giant cubby house. Of course, if the walls are only ten-to-12 millimetres thick, you may find that they actually resonate and cause even more issues. You may need to use at least two or three layers of ply to make it viable.
A simple stud wall is relatively easy to construct out of lightweight radiata pine. It'll be most effective if you can leave a small air gap between the original wall and the ‘false’ wall, and also make the inner room free-standing so that sound is not transferred from mechanical connection. You can include a false ceiling to completely seal the room in. Once again, bringing in a tradesman, even just for advice, may be a good idea if you want to make sure it stays in place!
If you’re going to go to that amount of trouble, you may as well try setting the walls at a slight angle to each other to minimise standing waves. These occur when you have a frequency with a wavelength that matches the dimensions of two parallel walls. The result is that you end up with ‘nodes’ and ‘anti-nodes’ as the wave bounces between the two surfaces – points where the frequency is boosted in amplitude, and points where the frequency cancels itself out. This is obviously a nightmare when recording or monitoring low frequencies, as their wavelengths are often longer than the dimensions of a small room.
Another potential fix is to erect a series of acoustic baffles around the room. This is much easier than trying to build a permanent structure, though obviously not as effective. The baffles will work more like acoustic treatment than pure isolation – though it will assist, to some degree, with reducing sound transference.
Of course, don’t forget that if you do create an isolated booth, you’ll still need to bring in power, lighting and air. Once again, this is quite complex – especially getting fresh air in and out, not to mention temperature control. Heating is not an issue, though cooling is very difficult (unless it’s going to be a permanent setup).
A novel (pun intended) – though far more manageable – approach to buffering sound without actually having to build anything is to line the walls with bookcases and fill the shelves with books! Of course this won’t give you a fully enclosed room, but the weight of the books will have a dampening effect on the room, and provide the all important uneven surface which will scatter frequencies and flatten things out.
In the next article, we’ll look more closely at the much easier task of treating the room acoustically. A room inside a room is just the beginning, after all. It will still need to be treated in order to create an even, natural sounding space. Meanwhile, do some research into products and methods that people have used to transform spaces. Chances are that whatever your situation is, someone else has been there already!