Cabling and phantom power
Signal processing and special effects
PC card and CD-R recorders
Hard disk recorders
Improving audio digitization
Analysis and Delivery
Preparing files for analysis and delivery
LPC in acoustic analysis
Audio Technology / Recording / Microphones / Cabling and phantom power...
Cabling is a common cause of recording problems. In order to avoid noise
(60 Hz hum) and phase problems, it is recommended to use professional
quality balanced XLR (two conductors for the signal with neither connected
to the shield) cables to connect the microphone to the pre-amplifier PHOTO>>.
If the pre-amplifier does not have balanced XLR inputs, one should use
a balanced to unbalanced transformer (Ebtech Line shifter PHOTO>>,
CP8201 In-Line Transformer). The transformers primary side matches
the impedance of the microphone and is balanced, while the secondary side
is unbalanced and has high impedance that matches most unbalanced pre-amplifier
inputs. Condenser microphones require a 48 V phantom power. While some
microphones, such as AKG C1000 can work from an internal battery source,
others require an external phantom power supply, which many good pre-amplifiers
and mixing consoles come equipped with.