2:1 Rule Of Ambience:
What is the 2:1 rule of ambience? The 2:1 rule of ambience states that a cardioid microphone must be positioned twice as far from a sound source than an omnidirectional microphone in order to capture equal amounts of room ambience.
What is the 3:1 microphone rule? The 3:1 rule of thumb states when two mics are capturing a source (or multiple sources in one space), the mics should be separated by a distance 3 times that of the shortest mic-to-source distance. Another 3:1 rule says a distant-mic should be at least 3 times further from a source than a close-mic.
10 dB Rule:
What is the 10 dB rule of microphones? The 10 dB rule is a general rule of thumb that states the following: when multiple microphones in close proximity capture the same sound source, it's best to have at least a 10 dB signal difference between the dedicated mic and the auxiliary mics in order to minimize phase issues.
12th Fret-12 Inch Rule:
What is the 12th fret-12 inch rule of microphones? The 12th fret-12 inch rule states that it's best to start miking a guitar (or a similar stringed instrument) with a directional mic distanced 12 inches from and pointing at the guitar's 12th fret. From there, slight movements will likely get the mic to its sweet spot for close-miking the guitar.
94 dB SPL:
What does 94 dB SPL mean and what is its significance to microphones? 94 dB SPL is 94 dB stronger than the threshold of human hearing and is equal to a sound pressure level of 1 Pascal (variance in atmospheric pressure). The 94 dB SPL (or 1 Pa) tone at 1,000 Hz is a common tone for testing a microphone's output sensitivity.