Subliminal/Supraliminal help

Programming and Development General Audio Programming
14

This will do it:

;version 4

(setf cf 10000) ;modulation carrier frequency

(defun bandpass8 (sig lo hi)
  (lowpass8
      (highpass8 sig lo) hi))

(setf *track* (bandpass8 *track* 150 4000))
(setf *track* (mult *track* (hzosc cf)))
(bandpass8 *track* (+ cf 150) (+ cf 4000))

and to decode:

;version 4
(mult 1.2 *track* (hzosc 10000))