one of the great heroes of sounddesign for film is walter murch. he's primarily known for his work on 'the godfather' and 'apocalypse now', but my personal favorite is george lucas' 'thx 1138', from 1971. it's quite an experience to just listen to the audio of this film. murch is also known for inventing all kinds of techniques to manipulate sound. i'll explain one and show how we can replicate it in ableton live.

nowadays we are used to artificial reverb with tails of 60 seconds or more. but back in the early days of reverb this could only be dreamed of. most spring and plate reverbs delivered a few seconds of reverb at most. echo chambers could stretch this to about 25 seconds, but beyond that was impossible. so what did walter murch do when he wanted huge reverb? he got creative.

he recorded a sound on a tape recorder at a speed of 7.5 inch per second (ips), sped the tape up to 30 ips, applied reverb and then slowed the tape back down to 7.5 ips. now he had the original sound with a reverb that was 4 times as long as the reverb he applied. he had in fact quadrupled the maximum reverb length he could achieve.

can we do something similar in ableton live? hell yes.

here's what i did: first, i resampled a microtonic loop at 125 bpm.

next, i warped the audio clip with the repitch algorithm and then quadrupled live's tempo to 500bpm. great for advanced gabber dancing. i then applied a 5 second reverb and resampled the master output. i warped this clip with the repitch algorithm too and put live's tempo at 125 bpm again. here's the result:

massive reverb.

there are many ways to extend this technique. for instance, you can turn the tempo down and then apply reverb. this will make your reverb shorter. and reverb is not the only effect you can apply. delay can work well too, especially when it's not beat-synced. as an example, i applied a 240ms delay to the loop after slowing it down 5 times. after speeding it up again, it sounded like this:

and beyond that there are tons of weird chorus, flanger and phaser effects waiting.

as demonstrated in the reverb example, when you speed clips up a lot before applying effects, the results definitely have a lofi character. this is mainly due to the limitations of digital audio. when you increase the tempo with the repitch algorithm engaged, the pitch goes up, just as would happen with tape or a vinyl record. but by doing so, a part of the audio will possibly be shifted beyond the maximum frequency that can be handled inside the daw. this frequency is always the sample rate divided by 2: at 44.1 khz it's 22.05 khz, at 96khz it's 48khz. audio that is shifted beyond that frequency, is gone forever.

also, applying reverb and then making a clip 4 times slower, effectively pitches the reverb down 2 octaves. it's not just a longer reverb, it's also a pitched-down reverb with less high-frequency content.

but, despite these limitations, this technique can give very usable results. it's hard to predict what will happen, so there is an element of surprise. and surprise is always a good way to get those creative juices flowing.