An audio converter for when the format is the problem
You usually reach for an audio converter because something will not play: a car stereo that ignores FLAC, an editor that will not import WMA, a phone full of voice memos in M4A that a website refuses. The common advice is a command-line tool or a full audio editor that exports one file at a time.
Any Sound Converter does the conversion as a batch. Drag in files or add a folder, push in the cartridge for the format you want, and press Convert. On the way in it accepts twelve audio types: lossless FLAC, WAV and AIFF; compressed MP3, M4A, AAC, WMA, OGG and Opus; AMR phone recordings; AC3 soundtracks; and MKA. On the way out there are nine cartridges, covering every one of those except the last three.
Hover a cartridge and it tells you what that format is for. MP3 plays on everything. FLAC is about half the size of WAV with nothing lost. M4A suits Apple devices. Opus gives the best quality for its size. If you are not sure, the defaults are sound choices and you can convert without opening a single setting.
How to convert M4A, FLAC or WMA to MP3 in bulk
By default, each new file lands beside its source with _converted added to the name, so nothing is overwritten. Title, artist, album and the other text tags are copied across to the new file. Cover art is not.
- Drag your audio onto the window, or use Add files or the folder button beside it.
- Push the MP3 cartridge into the rack.
- Under Bitrate, leave Best (variable) for high-quality variable bitrate, or pick a fixed 128 to 320 kbps.
- Choose where Save converted files puts the results, then press Convert.
Bit depth, sample rate and channels for lossless output
Pick WAV, AIFF or FLAC and the settings change to match. Bit depth offers 16-bit or 24-bit for all three, plus 32-bit float for WAV and AIFF. Sample rate stays as it was unless you choose 22.05, 44.1, 48, 88.2 or 96 kHz. Channels keeps the original layout or folds everything to stereo or mono, which is handy for spoken recordings that only need one channel.
Lossy formats have their own limits, and the app enforces them rather than letting a setting silently fail: M4A and AAC are always stereo at 44.1 or 48 kHz, and Opus always runs at 48 kHz.
Normalize audio volume so every track plays at the same loudness
Mix songs from different albums, or episodes recorded on different days, and some will be noticeably louder than others. Turn on Normalize loudness and every file is leveled to one target: -23 LUFS for broadcast, -16 LUFS for podcasts, or -14 LUFS for streaming, with peaks held below clipping. If you only want a fixed change instead, switch Normalize off and the Gain slider appears in its place for a fixed boost or cut of up to 12 dB.
Before converting, select a file to see its measured Loudness in LUFS, its True peak in dBTP and its loudness Range. A true peak marked May clip once it's compressed is your cue to leave Normalize on.
Trim, fade and listen before you convert
Select a file and switch between the Waveform and Spectrogram tabs. Drag the handles to cut silence or chatter from the start and end; the Starts, Ends and Keeps readouts show exactly what survives, and that trim belongs to that one file. Press play to hear it while the twin VU meters move.
Fade in and out is different: it is a batch setting, up to 30 seconds at each end, applied to every file in the run. Neither the trim nor the fades touch the source file.
