PCRECORDING.COM - - Acoustics
Most of us cannot afford to acoustically treat our recording area like the pros do. In fact, most of us home recording types have dual duty spaces where we do our recording, e.g., they serve also as bedrooms, dens or offices. Whether we like it or not, our recording rooms will be acoustically active. As such, they become part of the instrumentation in that they affect the way we perceive sound. Therefore, like anything other instrument, you have to try to "tune" your room to achieve the best possible result. There are a number of different techniques one can use to significantly improve your recording room acoustics and limit their effects on your recording.
First, let's talk about speakers. At minimum you must try to use speakers that have a relatively flat response. Study your speaker manual and see just what its specifications are. If you do not have particularly flat speakers, at least learn where they are not flat and figure out a way to compensate when mixing down. If possible, your flat response should lie between 40 Hz and 16-18 kHz. If you can afford it, try to get some near-field monitor speakers. Talk to your music pro, listen to a bunch of them, and make a purchase with your budget and ears.
Speaker placement is critical to achieving a balanced sound during mixdown. Your pair of speakers should form two points of an equilateral triangle and your sitting position the third. In addition, the speakers should be equidistant from the sidewalls. The speaker should be at your ear level between 5-7 feet from you. In this way you ensure that you avoid phase problems due to differing distances from the speakers.
Room dimensions play a critical role in how a room acoustically acts. The size of the room is one factor that determines which frequencies may be enhanced or diminished. This is because some frequencies will resonate at elevated (louder) levels in what are called "standing waves."
Apply this formula: f1=1,130/2L = 565/L. 1,130 is the speed of sound in feet per second, L equals the length of your room.
For instance if your room is 12 feet long you would get a standing wave at 45 Hz. Multiples of this frequency will result in more standing waves though they diminish in volume and get closer together further up the frequency range. For instance, the next standing wave would occur at 90 Hz, the next after that at 135 Hz, and so forth. These standing waves, and each multiple of it, may affect your ability to accurately perceive your audio mix. That is unless you know they are there.