The dynamic range that can be represented by a 32-bit (floating point) file is 1528 dB. The largest number which can be represented is ~3.4 x 10 38, and the smallest number is ~1.2 x 10 -38. More info is available regarding this format (called IEEE-754).
The first bit indicates a positive or negative value, the next 8 bits indicate the exponent, and the last 23 bits indicate the mantissa. The formatting and encoding of the 32-bit word is not intuitive–it has been optimized for computers to be able to perform common math functions on it rather than for human-readability. This difference is significant because much larger and smaller numbers can be represented compared to a fixed-point representation. This is fundamentally different than fixed point, because numbers in these WAV files are stored with “scientific notation”, using decimal points and exponents (for example “1.4563 x 10 6“ instead of “1456300”). Presently 24-bit, 48 kHz WAV files are the most widely-used files in the professional audio community.Ĭompared to fixed-point files (16- or 24-bit), 32-bit float files store numbers in a floating-point format.
For an increase of 50% in storage space compared to 16-bit files the dynamic range captured goes from 96 dB up to 144 dB, a substantial increase in performance. Each audio sample consumes 24 bits of space of digital storage, and at a 48 kHz sample rate, this means that 24 x 48,000 = 1,152,000 bits per second are needed for a single channel, 24-bit, 48 kHz file. Just like for 16-bit files, audio recorders and DAW software call the largest signal in a 24-bit WAV file 0 dBFS. The dynamic range of a 24-bit (fixed point) file is (0 dB – (-144.5 dB)) = 144.5 dB A 16 bit number in binary form represents integers from 0 to 65535 (216).ĭoing the same math with 24-bit files to calculate the noise level and the maximum levels results in the following:ĭB noise = 20 x log (1/16777216) = -144.5 dBĭB max = 20 x log (16777216/16777216) = 0 dB These numbers are “fixed-point”, because they are whole numbers (no decimal point). Traditional 16-bit WAV files store uncompressed audio samples, where each sample is represented by a binary number with 16 digits (binary digit = “bit”). This paper discusses the differences between 16-bit fixed point, 24-bit fixed point, and 32-bit floating point files. To understand the nuts and bolts of 32-bit files, keep reading. Audio levels in the 32-bit float WAV file can be adjusted up or down after recording with most major DAW software with no added noise or distortion.
There is in fact so much headroom that from a fidelity standpoint, it doesn’t matter where gains are set while recording. The primary benefit of these files is their ability to record signals exceeding 0 dBFS. For ultra-high-dynamic-range recording, 32-bit float is an ideal recording format. The MixPre II models introduce the ability to record 32-bit floating point WAV files.
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