Digital Sound & Music: Concepts, Applications, & Science, Chapter 4, last updated 6/25/2013
horn outside the building, and that sound gets picked up on the microphone inside the studio.
That recording is now unusable, and you have to ask the musician to attempt to repeat his perfect
One strategy for allowing appropriate windows and doors into the building without
compromising the acoustic isolation of the studio is to build a room inside of a room. This can be
as small as a freestanding booth inside of a room, or you can build an entire recording studio as a
room within a larger room within a building. The booth or studio needs to be isolated as much as
possible from any vibrations of the larger room. This is sometimes called floating the room in a
way that no surface of the booth or the studio physically touches any of the surfaces of the larger
room that come in contact with the outside world. For a small recording booth, floating can as
simple as putting the booth on large wheel casters. Floating an entire studio involves a
complicated system of floor supports that can absorb vibration. Figure 4.38 shows an example of
a floating isolation booth that can be used for recording within a larger room.
Figure 4.38 A small floating isolation booth. Photo courtesy of WhisperRoom Inc.
The other isolation concern when recording is isolating the microphones from one
another and from the room acoustics. For example, if you're recording two musicians, each
playing a guitar, you want to record in a way that allows you to mix the balance between the two
instruments later. If you have both signals recording from the same microphone, you can't adjust