Strip music beds from interview audio, hit -16 LUFS for Apple Podcasts and Spotify in one pass, and verify true-peak before you push the upload button.
Network-grade podcast audio used to mean a $60/month plugin bundle and an audio engineer on retainer. SignalKey gets you the loudness checks, voice isolation and true-peak headroom verification independent podcasters need — without the subscription.
Every tool below is free, no signup, no watermark. Click any card to open it.
Pass / fail against Apple Podcasts (-16 LUFS), Spotify (-14 LUFS) and Amazon (-16 LUFS). True-peak warning at -1 dBTP.
Pull a clean voice track out of an interview that recorded over background music. Works for archival recordings too.
When the vocal isolation isn't enough, the 4-stem split lets you mute drums, bass or music separately for forensic clean-up.
Diagnose room rumble, AC hiss or fluorescent buzz before they end up in the master. Real-time mic input.
Verify your reference tone (e.g. test signals or musical interludes) is at concert pitch.
How a self-publishing podcaster uses SignalKey on a typical episode.
Open Spectrum Analyzer with your USB mic. Watch for low-end rumble (HVAC) and high-end hiss (fluorescents). Move the mic, kill the offending source, then start recording.
An interview was recorded over a coffee-shop playlist. Drop it into Vocal Remover — voice stem cleans up dramatically. If it isn't enough, jump to Stem Splitter for forensic separation.
Bounce the rough cut. LUFS Meter says -19 LUFS — too quiet for Apple Podcasts (target -16). Push the master limiter up 3 dB, re-check. True-peak still safe at -1.4 dBTP.
Re-run the analyser on the export. Apple Podcasts green at -16.0 LUFS. Spotify green at -14 (close enough for podcast normalisation). True-peak under -1 dBTP. Push to your host.
“Used to send every episode to a freelance engineer for loudness. Now I check it myself and ship before lunch.”
— Independent podcaster workflowApple Podcasts targets -16 LUFS integrated. Spotify, YouTube and Amazon all sit between -14 and -16. The LUFS Meter shows pass/fail for each service in one pane.
Drop a track and see the full analysis pass — BPM, key, Camelot, stems, MIDI, LUFS — in one go.