Sony PCM-D50 Operating Instructions Manual page 43

Item
LIMITER
7)
(Preventing distortion)
LCF
7)
(Low Cut Filter function)
SBM
7)8)
(Super Bit Mapping
function)
7) In digital recording, this function does not work.
8) The setting cannot be executed when the quantifying bit number is set to 24 bit in "REC MODE."
Options (Default settings are underlined.)
The recorder always reserves audio for the digital limiter, which is 20dB
lower than audio processed in the normal circuit. This compensates for
clipping that happens during digital processing if audio is over-input.
When the LIMITER switch is set to "ON," the digital limiter circuit operates.
The following are the times required for recovery:
150ms The recorder recovers from the affects of the digital limiter circuit
within approximately 150ms.
1 sec The recorder recovers from the affects of the digital limiter circuit
within approximately one second.
1 min The recorder recovers from the affects of the digital limiter circuit
within approximately one minute.
Notes
The limiter circuit functions to keep the signal level below the maximum input

level. When a loud sound is input suddenly, the excess part of the sound is
automatically set within the range of the maximum input level in order to prevent
distortion.
The limiter circuit of the recorder does not compensate for clipping when audio

over 12dB is input. In this case, sound may be distorted.
When the setting is "ON," the peak value with the limiter circuit in operation

appears if the maximum peak value exceeds 0 dB.
When the LOW CUT FILTER switch is set to "ON," the low cut filter is
activated so that audio under the following frequencies is filtered and is not
recorded. This function reduces noise caused by the flow of air-conditioning
equipment, outdoor air, etc.
75 Hz Audio under 75 Hz frequency is not recorded.
150 Hz Audio under 150 Hz frequency is not recorded.
Super Bit Mapping reduces noise when the quantifying bit number is set to
16 bit in "REC MODE."
ON The super Bit Mapping functions to reduce noise.
OFF The super Bit Mapping does not function.
Note
Super Bit Mapping significantly increases the dynamic range acoustically by

reducing noise that is particularly easy to hear within the human audible band. In
order to improve the audio quality when converting 20-bit data into 16 bit, the top
4-bit amount of information within the lower data, which is usually thrown away, is
integrated into the 16-bit data.
Continued on the next page
43