Javier Zumer has a cool post up on his blog about Using Shotgun Microphones Indoors.
I have been researching an idea that I have been hearing for a while:
It’s not a good idea to use a shotgun microphone indoor.
I want to check this question out and, eventually, make some tests. Here we go!
The main goal to these devices is to enhance the axis captation and to attenuate the sound coming form the sides. In other words, make the mic the more directional as possible in order to avoid unwanted noise and ambience.
To achieve this, the system cancels unwished side signals delaying them. So, the operating principle is based in phase cancellation. At first the system had a series of tubes with different sizes that allows the axis signals to arrive in the same time but forces the off-axis signals to arrive delayed. This idea, created by the prolific Harry Olson eventually evolved in the modern shotgun.