As part of one the assignments I did at college, we learned how to assess how suitable a room could be on an acoustic level, which would give us an idea of how we could record and mix in the room examined.
We were given a chart with a total of 6 rooms, divided into small and large and then told to pick one large and one small from the list to be evaluated. In addition to this our lecturer had recorded a snare drum in each of the rooms listed, each of which sounded different due to the layout and size of the room.
|Little rooms||Big rooms|
|Studio 1 vocal booth.||Studio 1 live room|
|Project room.||Performance space|
|Studio 1 drum booth.||Empty Room next to Lecture Theatre|
Our task consisted of two parts, the first was to analyse the room, to work out its frequency response, and second was to use that knowledge to apply a reverb effect to an anechoic snare (i.e. a snare recorded with a minimum of room ambience present.)
I chose to use the Studio 1’s Drum booth for my small room, and the Empty room next to the Lecture theatre. (Pictured below.)
In order to recreate the snare recorded in these two rooms, I needed to first gather some information about the size and layout, because if rooms dimensions included one or more symmetrical walls, floor or ceilings, or a figure which divides into a multiple of the wall sides will cause axial modes, and standing waves.
Axial modes are caused by sound waves bouncing off the surfaces in the room, and at certain angles, (axis) select frequencies will resonate causing standing waves. In addition to this, each of these frequencies has integer harmonics that also resonate.
The lowest of these harmonics is called the fundamental frequency, which causes the standing wave because its wavelength exactly fits the distance between the two walls, and as the integer harmonic frequencies do at their multiple (example 2nd Harmonic will become a problem because it will fit exactly twice within the room.)