BEATS WITH KEVHOW IT WORKS
What gets measured, how it’s graded, what to fix first, and the real DSP running underneath. In plain language.
WHY THIS EXISTS
Ears get less reliable over time. After a few hours on a mix, ears adjust and stop being a reliable judge. Signal Check runs the same loudness, dynamics, stereo, frequency, and true-peak checks a mastering engineer would reach for by hand, so a read doesn’t depend on how tired the ears doing the listening are.
THE 5 READS
Five reads cover a mix. Each one has a headline number and a second, closer look underneath it.
- Loudness. Integrated level in LUFS against streaming and genre targets, so the number means something instead of just being big or small. The loudest section gets its own reading, because that’s the part a limiter and a streaming platform react to first.
- Dynamics. How much a mix breathes versus how flat it’s been pushed. Crest factor covers the whole track. PSR covers the loud parts, which is where dynamics get crushed.
- Stereo. Width and mono compatibility, so a wide master doesn’t collapse or phase out in mono playback. The low end is checked separately, since bass spread wide in stereo is bass that thins out on a phone speaker.
- Frequency. Band-by-band tonal balance against a genre tilt: too much bass, not enough top, or graded as balanced. Ringing resonances in the 2 kHz to 5 kHz range get their own test, with the frequency of the worst offender.
- True peak. Clipping risk, and how often a track rides right at the ceiling. You get the count of clipped samples, not just a yes or no.
- LEVEL has loudness, dynamics and clipping. TONE has the frequency balance and the resonance test. SPACE has stereo. COMPARE puts your track next to a reference. REPORT has mastering readiness and the one-sheet. Keys 1 to 5 switch between them.
- The transport strip sits above every view: play, loop, the stereo, mid and side monitor, what you’re graded as, the #1 fix, and integrated LUFS. Momentary and short-term LUFS read live while the track plays.
- On a phone, the same sections sit in a row of tabs, with a SUMMARY tab at the end.
- Three charts, one at a time. FIELD shows where each frequency sits between left and right. A bigger dot means that band carries more of the track.
- MONO FOLD shows how many dB each band loses when the mix sums to mono. PHASE shows correlation band by band, from -1 to +1.
- Drop in a track you’re chasing and it runs through the same engine as yours. The shelf holds your last three references, so you can switch between them.
- The delta spectrum plots your balance minus the reference’s across 30 bands. Each track gets read against its own average first, so a louder file doesn’t push every band up.
- A checklist for the context you picked: true peak, dynamics, mono compatibility and clipping. Under it, your sub, low-mids and mids sit next to the range released records land in.
GRADED IN CONTEXT
Every check runs in a context. There are two: Mastered and Reference. Mastered is the default. It grades your track as a finished release, against the genre you pick.
Reference turns grading off. It describes what a track is doing instead of scoring it, which is how you read a release you admire without holding it to your own targets.
THE DIAGNOSIS
Every analysis ends with a sentence. On a phone, you get a shape too.
- Five axes, the same five reads: loudness, balance, stereo, dynamics, peaks.
- A bigger shape means fewer problems. A point turns red where a reading needs a fix, so one look tells you where the track is weak.
- It lives in the SUMMARY tab on a phone. The desktop views leave it out.
- Signal Check ranks the hard problems (clipping, true peak and phase) by how far past the line each one sits. The worst one goes to the top as one plain sentence: the #1 FIX box in the strip on desktop, the SUMMARY tab on a phone.
- A track with six things flagged still has one place to start.
SHOW THE RECEIPTS
- Open the receipts and each measured value sits next to the line it’s read against. Integrated loudness gets checked against Spotify’s -14 LUFS, the loudest section against its target zone. True peak, clipped samples, PSR, crest factor, and stereo or mono are in there too.
- You get to see why a reading was called red, rather than taking the grade on faith.
- Change something, bounce it, run it again. Signal Check keeps your last check and shows the before and after: old value, arrow, new value. It tracks integrated loudness, the loudest section, true peak, crest factor, PSR and clipped samples, and lists the ones that moved.
- That’s how you find out whether the fix landed, before you commit to it.
The receipts and the re-check sit in the phone layout’s SUMMARY tab, under DETAILS. On desktop, each view prints your number next to its target, and the REPORT view lines them all up on one sheet.
THE SCIENCE
- Gated integrated loudness in LUFS, K-weighted per
ITU-R BS.1770-4, the same standard streaming platforms use for normalization. - Short-term loudness runs on a 3-second window with a 100 ms hop. The loudest section is the 95th percentile of those windows, so a single freak moment can’t define it.
- Graded against genre-specific target ranges, not one fixed number for every track.
- Crest factor:
20 × log10(true peak ÷ RMS), in dB. A wide gap means the mix still breathes; a narrow one means it’s been pushed hard. - PSR is the gap between the peaks and the short-term loudness around them, taken as the median across the loudest quarter of the track. It catches a squashed drop that a quiet intro would otherwise hide in the whole-track average.
- Per-band correlation from the cross-spectrum of the left and right channels, not just one overall mono-sum check.
- Width and mono-compatibility loss are both derived from that same per-band correlation data.
- The low band gets its own mono-compatibility read, because that’s the range where a wide image costs you the most on a single speaker.
- Hann-windowed FFT, analyzed across the full track and averaged, not a single snapshot.
- Balance is graded against a genre-specific tonal tilt, not one flat curve every genre gets held to.
- The resonance test hunts narrow peaks in the 2 kHz to 5 kHz band and reports the worst one by frequency. It is separate from the HIGH-MID level: a band can sit on target and still ring. Four narrower bands from 1 to 8 kHz are each checked against their own average too, so a peak near 5 kHz is not hidden by the louder 2 kHz end. A band outside 2 kHz to 5 kHz that rings gets its own cut in the suggested EQ moves.
- True peak isn’t the loudest sample. It’s the loudest point the waveform reaches between samples, which is what actually clips a D/A converter or codec on playback.
- Found via 4x-oversampled inter-sample peak detection with windowed-sinc interpolation, the method defined in
ITU-R BS.1770-4.
STAYS LOCAL
Nothing leaves your browser. No upload. No account. No server ever touches the audio. Every measurement runs locally, and the one previous check kept for the before-and-after comparison is stored in your own browser too.
EXPORT THE BREAKDOWN
The report is one printable sheet: your numbers next to the target, the fix list in order, and what Spotify, YouTube and Apple Music do to your loudness when they normalize it. Save it as a PDF and keep it next to your DAW.
The carousel is 10 slides: the numbers, the verdict, and a plain read of what’s happening in the mix, ready to post or send to a collaborator.
Both ask for your email. Running the check never does.
WHO IT’S FOR
For producers finishing a mix without a mastering engineer on call, checking a bounce before it goes to a label or playlist curator, or just wanting a second opinion that isn’t a friend’s ears at 2am.
RUN A CHECK
Drop a track in and get the full read in seconds.