High Quality Signal Processing
The PCM-D1 recorder offers comprehensive signal processing features for location recording including a unique limiter function, a 200 Hz high pass filter and SBM (Super Bit Mapping) noise shaping. With the High Pass Filter enabled, audio below 200 Hz is filtered out and not recorded. This function can be used to reduce noise caused by external sources such as wind, the flow of air-conditioning equipment, etc. With the SBM function enabled (optionally used for 16-bit recording modes), Super Bit Mapping significantly increases the dynamic range acoustically by reducing noise that is particularly easy to hear within the human audible band. To improve the audio quality when converting 20-bit data into 16-bit, the top bits of information within the lower data (usually discarded when recording in 16-bit mode) are integrated into the 16-bit data track by shifting audible noise up into an inaudible higher frequency range.