Hz: pitch and a tuning reference
A hertz is one cycle per second. A pure 440 Hz tone completes 440 cycles each second. With A4 = 440 Hz tuning, that frequency is the reference for the note A4. Music contains many notes and frequency components: a “432 Hz music” label does not mean the whole file is a single 432 Hz tone.
Retuning from A4 = 440 Hz to A4 = 432 Hz multiplies frequencies by 432/440, approximately 0.981818. That is about 31.77 cents lower; a semitone is 100 cents. A file need not contain reliable information about its original tuning. Not every recording starts at 440 Hz.
kHz: how many samples we store
44.1 kHz means 44,100 samples per second in each channel. At 48 kHz there are 48,000. This is sample rate, not the pitch of a note. A 440 Hz tone can be stored at either rate.
Proper sample-rate conversion preserves duration and pitch. Reinterpreting the same samples at another rate without resampling is different: playing 44,100 samples at 48,000 per second makes the audio faster and higher. Similar-looking numbers, very different results.
Increasing an old recording’s sample rate cannot restore missing detail. For a straightforward conversion, keep the source rate unless your project or playback device needs another one.
kb/s: how much data per second
320 kb/s means a nominal 320,000 bits per second. For compressed audio, bitrate helps estimate file size. One minute at a constant 320 kb/s is about 2.4 MB of data; at 192 kb/s it is about 1.44 MB. Headers and metadata add bytes. With variable bitrate, the result depends on the average rate.
A higher bitrate can reduce encoding losses, but cannot repair a poor source. Converting a 128 kb/s MP3 to 320 kb/s makes a larger file without recovering discarded information. A larger box still holds the same present.
16-bit and 24-bit: sample precision
For integer PCM, bit depth describes the number of possible sample levels. 16 bits provides 65,536 levels; 24 bits provides 16,777,216. Greater precision reduces quantisation error. It is not a volume control.
24-bit recording can be useful for capture and processing. Simply saving a finished 16-bit file as 24-bit adds no information by itself. Appropriate dithering is used when reducing bit depth. Floating-point formats are a separate subject and should not be treated as equivalent to integer PCM.
Listen: 432 Hz and 440 Hz
We created two separate sine tones: 4 seconds each, mono, 48 kHz, 16-bit PCM, equal amplitude and gentle fades at both ends. They illustrate frequency, not converter performance or music quality. Start with low playback volume.
Which setting fits your task?
- Smaller file: choose a suitable format and bitrate; keep the original.
- Different musical tuning: use pitch shifting. Keeping the tempo requires processing that preserves duration.
- Sound for a video project: match the project sample rate, often 48 kHz.
- Simple format conversion: leave tuning unchanged and avoid unnecessary conversions.
Our FLAC or MP3 guide explains lossy and lossless compression. Visit Perun Audio Converter for information about our tool. Choose the task first, then the settings. The numbers do not all need to go up.
Technical sources
Audacity: digital audio fundamentals · UNSW: note names and frequencies