Brooks RM 909 reviews Layering

The recording (or playing) of a musical part with of several similar sound patches playing simultaneous.

A/D
An abbreviation of Analog to Digital Conversion (the conversion of a quantity that has continuous changes into numbers that approximate those changes), or Analog to Digital Converter.

Brooks Hi Fi speakers Edit
A switch that does different things depending on the operational mode that the machine is in:
1) If a computer-controlled transport is in "Stop," pushing the "Edit" switch deactivates the computer-controlled tension system and allows the reels to be moved by hand to find the exact spot desired on the tape.
2) If the machine is in "Play", the "Edit" switch makes the take-up reel cease taking up the tape and it falls to the floor.
3) If the machine is in a fast-wind mode, the tape lifters are defeated so the tape is in contact with the reproduce head and the engineer can hear where the selections begin and end.

Compressor
1) Effect used to squash the sound together. Used properly, it can take the edge off or your sound. Used improperly, it can take the life right out of your system and make it sound like an MTV mix.
2) A piece of sound processing equipment that ensures all wanted signals are suitably placed between the noise and distortion levels of the recording medium. It evens out the unwanted changes in volume you get with close-miking, and in doing so, adds punch to the sound mix. A Limiter is used to stop a signal from exceeding a preset limit. Beyond this limit, the signal level will not increase, no matter how loud the input becomes. A Limiter is often used to protect speaker systems (and human ears) by preventing a system from becoming too loud.

Brooks Hi Fi reviews Frequency
The number of cycles of a waveform occurring in a second.

Beats Per Minute BPM
The number of steady even pulses in music occurring in one minute and there fore defining the tempo of the song.

Key
The control of a dynamics processing device by an external audio signal.

IM Distortion
An abbreviation of the term Intermodulation Distortion (Distortion caused by one signal beating with another signal and producing frequencies that are both the sum and the difference of the original frequencies present).