live browser experiment

The song is also a tiny modem.

This page uses the Web Audio API to split the finished stereo WAV into left and right channels, reconstruct (left - right) / 2, and inspect the exact 18 kHz and 20 kHz frequencies that carry a byte-identical SQLite database. It is not pretending an <audio> tag is signal processing; the graph below is computed live in your browser.

Stereo-side spectrum

Press the button to create the audio graph; the database carrier begins 2.5 seconds into the track.

0 carrier -- 18 kHz not measured
1 carrier -- 20 kHz not measured