In terms of pure physics, you still have to deal with standing waves, early reflections and all the same issues. In fact, in the tracking room these problems may be amplified (literally), as you may be dealing with loud sound sources like drum kits and guitar amps. Many people opt to simply deaden the room as much as possible to kill all those reflections, covering the room with acoustic foam, then adding “character” to the sound in the mix using effects. While this approach works for some styles of music, it may not be the best solution for rock and other “organic” genres where you want a more “live” sound.
Moreover, an oft overlooked fact is that the sound of the recording room dramatically affects the tone of the recorded instrument, including vocals. In fact, you can think of the room as being like a giant equalizer, where the early reflections in the room combine with the original sound source to produce the overall timbre of the instrument or voice. You can take away those early reflections as much as possible to get an acoustically “purer” sound, but in the process you lose much of what enlivens a sound in the natural environment and gives it character. And of course, it’s difficult to substantially change the basic timbre of an instrument in the mix.
So how to retain the character of early reflections, especially in a small room, without dealing with standing waves and other phasing problems? Some compromise is necessary. You can approach treatment of your tracking room a bit differently than a control room because after all, in the tracking room you aren’t striving for “accuracy” so much as “musicality” — you just want the instruments to sound good in the room. And luckily you can measure that without complex calculations or expensive instruments; all you need is ears. So, here are a few tips to help you achieve a good balance between “sonic character” and “acoustical problem.”
Don’t deaden everything. Don’t put foam all over the room. Leave some reflective surface on the walls, or cover two walls and leave each opposite wall mostly untreated. Same with the floor and ceiling: In most cases you want an absorptive ceiling and a reflective floor, so for best results, you want a wood or linoleum floor (not carpeting) and a drop ceiling or foam treated ceiling. If you have carpeting in your room, consider putting plywood down on the floor while recording; I’ve had good luck recording drums and guitar amps this way in small rooms, tacking up foam on the ceiling. Unless you’re deliberately going for a deader sound, live instruments tend not to sound great on padded carpeting.
Use bass traps. You’ll achieve a much more solid low end by the liberal use of bass traps. Many bass traps, such as Mini Traps from RealTraps, are slightly reflective in the high end so that they don’t completely deaden the room, yet they do an effective job of killing standing waves in the low end.
Build some baffles. Using baffles rather than treating all of the walls lets you adjust the location and number of baffles so that you can adjust the amount of “liveness” in the room, or on individual instruments. Put baffles around a drum kit, amp, or vocal mic for a deader, more close-miked sound; move them further away or eliminate them for more reflections. It’s a great exercise to move baffles around while listening, so that you can hear the dramatic effect they have on the timbre of the instrument or voice. And remember, vocalists can turn in a much more confident performance when the sound of the room meshes well with their voices.
If you’re in a small home studio where you track and mix in the same room, you can still employ many of these techniques. By using as many bass traps as you can and building moveable baffles, you can increase and change the reflections in the room when tracking, and deaden them when mixing. If you prefer a very dead room while mixing, treat one side of each baffle with foam and the reverse side with more reflective material. This gives maximum flexibility in changing the room’s character to suit the task at hand.
Recording live instruments in small rooms is always a challenge, but there’s no need to track in a lifeless room. Many classic recordings have been made in less than “acoustically perfect” rooms, gaining an unmistakable character of their own as a result. Even hallways, stairwells, tiled bathrooms, and other acoustic nightmares can work, depending what kind of sound you seek. So ditch the foam for awhile and feel free to experiment! That’s the only way to find out for sure if you can defy the laws of physics.