text: can this be optimized? : ;;; Envelope follower for brick wall limiter
  (defun get-env (sig step lookahead limit)
    (let* ((sig (mult (/ limit) sig))
           (pad-time (* 3 lookahead))       ; padding required at start (seconds)
           (pad-s (* 3 step))               ; padding samples
           (padding (snd-const (peak sig pad-s) 0 *sound-srate* pad-time))
           (peak-env (snd-avg sig (* 4 step) step OP-PEAK)))
      (extract 0 1
        (s-max 1 
          (sim padding
            (at-abs pad-time (cue peak-env)))))))
  