Convert WAV to MP3
WAV files carry uncompressed PCM audio - typically 10 MB per minute at CD quality, more for 24-bit or higher sample rates. Wave decodes the PCM samples and re-encodes to MP3 at 192 kbps VBR through libmp3lame, shrinking the file by 8x while preserving everything a consumer playback chain can reproduce. Audio codecs explained walks through where WAV, MP3, and the rest each fit.
What actually changes
A WAV file is a RIFF container wrapping raw PCM samples. Bit depth is usually 16-bit (CD-quality standard from 1982) or 24-bit (studio-quality, common on modern DAW exports); sample rate is usually 44.1 kHz (CD), 48 kHz (video / broadcast), or 96 / 192 kHz (audiophile / archival). At the top end that means 5.5 MB per minute (16-bit 44.1 kHz stereo) up to 34 MB per minute (24-bit 96 kHz stereo) - enormous compared to the compressed formats consumer devices actually play from.
Because the source is uncompressed, the decode step is trivial - the PCM samples in the file ARE the audio. Wave hands them straight to libmp3lame, which encodes to MP3 at 192 kbps VBR (LAME -q:a 2). That falls inside the transparent-to-trained-listeners range for essentially all music and voice content: nothing audible is lost, but the file typically drops 8-12x in size. A 60-minute WAV at 24-bit 48 kHz that started at 830 MB lands as an 85 MB MP3 with visually indistinguishable audio.
WAV was co-designed by Microsoft and IBM in 1991 as part of the RIFF family (WAV for audio, AVI for video). It became the de-facto interchange format for the professional audio world - every DAW reads and writes WAV, every mastering house delivers WAV, every soundtrack composer's handoff to picture is a WAV. Its dominance is inertia at this point: FLAC would compress the same content losslessly to 60% of the size, but WAV's zero-cost decode and universal tool support keeps it in the workflow. MP3 is the delivery format at the end of that chain - the version people actually listen to.
A common surprise on WAV files: 32-bit float. Modern DAWs (Reaper, Pro Tools, Logic) frequently export 32-bit float WAV for headroom during mastering. LAME decodes those correctly through its internal float pipeline, but the extra dynamic-range headroom past 24-bit is invisible on any consumer playback gear (which caps at 16-bit output anyway). The MP3 sounds identical whether the source was 16-bit, 24-bit, or 32-bit float.
Three steps.
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Step 1
Drop the .wav file onto the card.
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Step 2
Wave inspects the source - PCM is always a decode-and-re-encode path.
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Step 3
Convert. Save the MP3.
Answers, specifically.
How much smaller is the MP3?
Roughly 8-12x smaller for typical WAV sources. A 60-minute 16-bit 44.1 kHz WAV that started at 630 MB becomes an 85 MB MP3. Higher-sample-rate WAV sources shrink even more.
Will the MP3 sound worse than the WAV?
Not on any consumer playback chain. LAME's 192 kbps VBR encode falls inside the transparent-to-trained-listeners range for music, voice, and film audio. Critical listening on studio monitors with tonally dense material is the only scenario where the difference is even theoretical.
Does 24-bit or 32-bit float WAV convert cleanly?
Yes. LAME works in float internally, so bit-depth conversion is transparent. The extra dynamic-range headroom past 16-bit isn't audible on any consumer speaker or headphones, but nothing audible is lost.
Multi-channel WAV (5.1, 7.1, ambisonic)?
Downmixed to stereo before the MP3 encode. WAV doesn't carry Dolby-style downmix metadata, so Wave uses the standard SMPTE fold (L, R = L + 0.707*C + 0.707*Ls; symmetrically for R). Dialogue stays anchored, effects preserve their approximate stereo positions.
What about broadcast WAV (BWF) with metadata?
Wave decodes the audio normally. BWF's bext chunk metadata (timecode, description, originator) doesn't map to ID3 through the current pipeline; the MP3 gets standard tags only.
Sample rates other than 44.1 or 48 kHz?
All standard rates decode: 22.05, 32, 44.1, 48, 88.2, 96, 176.4, 192 kHz. LAME resamples internally to the target MP3 sample rate (usually 44.1 or 48 kHz output depending on source).
How fast is a WAV to MP3 conversion?
Very fast - no video decode, and PCM decoding is essentially free. A 60-minute WAV finishes in about 15-25 seconds on a modern laptop.