SMF·PODCASTLE
Can a prompt replace Podcastle?
Audio & video editing — podcast recording, cleanup and publishing
Exhibit tracking slip
Verdict
The hard problem in a remote podcast is not editing, it is that the host has a treated room and a good microphone and the guest has a laptop in a kitchen. Fixing that means dereverberation, noise removal, spectral matching and per-track loudness normalisation, and open tools exist for every step. Assembling them into a pipeline that reliably improves a bad track rather than making it sound underwater is where the days go, and it is genuinely worth the days.
Exhibit A — The prompt
Received on31.07.2026Build a local multi-track podcast restoration tool. The goal is making separately recorded speakers sound like they are in the same room.
Project: one track per speaker, imported as separate files, plus optional music and effect tracks. Preserve originals untouched in a read-only folder; every operation is non-destructive and produces a new rendered result.
Analysis first, before any processing. For each track, measure and display: integrated loudness in LUFS, true peak, noise floor during silence, estimated reverberation time, and a spectral average. Show the tracks side by side, because the whole job is closing the gap between them and the user needs to see the gap. Never process a track that does not need it.
Restoration chain per track, each step toggleable with its parameters visible:
1. High-pass filter to remove rumble below the voice range.
2. Noise removal using a noise profile learned from a silent region the user selects, rather than a fixed profile. Apply spectral subtraction conservatively — over-aggressive removal produces the watery artefact that is worse than the noise.
3. Dereverberation, applied only where the measured reverberation time warrants it, with a clear before-and-after preview because this is the step most likely to damage a track.
4. Spectral matching: derive a corrective EQ curve that moves this track's spectral average toward a reference track the user nominates, limited to a maximum of a few dB per band so a bad microphone is improved rather than impersonated.
5. De-esser and a gentle compressor with visible thresholds.
6. Per-track loudness normalisation to a common target before mixing.
Comparison is a first-class control, not a feature: an A/B toggle that switches instantly between processed and original at matched loudness. Matched loudness matters — louder always sounds better, and an unmatched A/B makes every processing chain seem like an improvement.
Assembly: place tracks on a timeline with intro and outro slots, crossfades, and a music bed that ducks under speech automatically. Silence detection with a suggested-cut list the user approves rather than applies automatically.
Export: the mixed episode normalised to -16 LUFS for stereo podcast delivery, each cleaned stem separately, and a project manifest recording every setting so an episode can be re-rendered.
Out of scope: recording remote guests, any voice cloning or synthesis, transcription, collaborative editing, and cloud rendering.
Opening prefills the prompt — press enter to run it.
Exhibit B — What you lose
- B.1 the remote recording studio that captures each guest locally in the first place
- B.2 the AI voice and revoice features
- B.3 collaborative editing with a co-host
- B.4 cloud rendering, so long episodes occupy your own machine
Prior art
Exhibit C — Why people still pay: audio infrastructure, distribution, and production polish
Because the best fix happens at recording time, and a browser studio that records each participant's own microphone locally avoids the problem this build is trying to repair afterwards.
Questions
Can I import my Podcastle projects?
Finished audio downloads, and raw tracks if you recorded them there. Project structure, edits and settings do not export, so a project in progress should be finished where it is. Starting fresh with the raw stems is the clean path.
How much can this actually rescue a bad recording?
Noise and rumble, a lot. Reverb, some — a heavily echoey room improves but never sounds treated. Clipping and a microphone that was too far away, almost nothing. The analysis step exists so you know which of those you are dealing with before spending an hour on it.
What does it cost to run?
Nothing. Everything runs locally with open tools, so unlimited episodes cost only processing time — roughly real time for the full chain on a modern machine, which for a one-hour two-track episode is a coffee break.
What is the one thing that does not survive the rebuild?
Recording well in the first place. Podcastle records each participant's own microphone in their own browser, so the source material is already clean. Restoration after the fact is always a worse position than capture done right, however good the processing chain.
Related tools
Receipt