NeXT/Sun
A classic Internet audio format that grew up on NeXT, Sun, and DEC workstations.
Pro Audio Converter can convert audio files to and from NeXT/Sun (.au, .snd) via Core Audio.
This format is mainly used on NeXT, Sun, and DEC computers, and has become a standard for audio on the Internet. Audio can be stored as either Linear PCM or the more common μ-law.
Options for Linear PCM NeXT/Sun
Sample Rate — The number of samples of audio carried per second, measured in Hz or kHz (1000 Hz). 44.1 kHz is the sampling rate of audio CDs and 48.0 kHz is common for professional video. Higher sample rates result in higher quality audio with larger file sizes. Setting this to Auto creates an output file with the same sample rate as the input file. If the output file does not support the sample rate of the input file, Pro Audio Converter uses the greatest sample rate that is supported.
Bit Depth — The number of bits used to represent each sample. Increasing bit depth reduces quantization noise and improves the signal-to-noise ratio by about 6 dB per bit. 24-bit digital audio has a theoretical maximum S/N of 144 dB, compared to 96 dB for 16-bit. Audio CDs use 16 bits; 24-bit is common in professional audio and video.
Endianness — The byte order of each sample. Big Endian stores the most significant byte first; Little Endian stores the least significant byte first. By definition, NeXT/Sun files are always Big Endian.
Channels — The number of audio channels in the output file. Auto attempts to match the input file's channel count. You can also force Stereo (2 channels) or Mono (1 channel).
Quality — Good is optimized for the fastest encoding. Choose Better or Best (optimal for 24-bit sources) for higher quality. The tradeoff is between encoding speed and audio quality.