Waveform lab, round 2: A, B, C and F refined

Same Liquid Light background and layout; only the waveform changes. The audio is analysed into six bands with auto-gain, an envelope follower (fast attack, slow release) and an onset gate per band (spectral flux over an adaptive threshold). Round 2 runs every moving value through a spring or a wave simulation instead of mapping levels straight to pixels, and turns hits into motion that travels rather than flashes. The background is now a slow, soft morph that runs at full speed while playing and eases down to a crawl when paused. Round 1 versions are at the end for comparison. Press Play, then switch while it runs; keys 1 to 8 switch too.

What the research said, and how the analysis works

The pattern in the admired work: the best pieces give each frequency range its own visual job instead of having everything react to one loudness number. Emberflux runs three lines for bass, mids and highs, rippled by the waveform, with beat-triggered rings. On X, the waveform pieces people save most are 3D waveform landscapes and ribbons (@techartist_), Apple/Siri-style strands (@davidhaz, SiriWave), cubes that snap on and off on bass hits (@RedefineFX), and scope displays (Sungalizer). A Grok sweep of X found them; I did not check each post myself. Ridgelines come from Unknown Pleasures.

Why the old bars felt awkward: selectr fed raw FFT levels straight to the bars, so the bars twitched with every frame of noise, and a loud mix kept them near the top all the time. Motion-design practice (this guide, and the Bello onset tutorial) says: smooth with a fast attack and slow release, gate out the noise floor, calibrate to the mix, keep the output range narrow.

What this lab does with the audio:

Six bands: sub, bass, low mid, mid, presence and air.
Auto-gain per band: each band is measured against its own last ~3 seconds, so 0.5 means "normal for right now". A loud master no longer pins everything.
Envelope follower: about 15 ms attack and 250 ms release. Hits land instantly and fall off smoothly. These are the teal meters under the canvas.
Onset gate per band: spectral flux (how much the band just jumped) compared with its own recent average plus 1.6 standard deviations. When it crosses, the gate fires a 1 that decays, with a short lockout so one hit fires once. This is the gate idea: motion triggers on hits, not on level. These are the gold meters.
Beat clock locked to 132 BPM, used for rhythmic decay in F and ridge timing in C.
Springs on the fall only: every moving value jumps up on a hit in the same frame, and only the way down is sprung or eased, so hits land on the beat and still settle smoothly.
Analysed ahead of time: the clip is analysed once at 10 ms steps before playback, and each frame looks up the analysis at the moment you are hearing (playback time minus the browser's output latency). Nothing waits on a live FFT window, so there is no analysis lag. Add ?lead=60 to the URL to push the visuals earlier if they still feel late on your setup (default 30 ms).