i am working on a project where i crash together 2 foot copper and steel boxes in mid air (using a pneumatic colliding machine i made - yes, silly...), and i use old 16mm film to record slow motion of the collisions, and record sound using piezo film sensors and standard mikes. what i would love to know is possible ways to slow down the audio 40 - 100 times (yes, a lot) using digital means. i am NOT a sound designer, but i am trying as much as i can. i have tried phase vocoder stuff, which smears the transients and all detail, i have tried paul's extreme sound stretch (which does the same, obviously, though is more suited to extreme stretching), i have tried reel to reel, re-recording and building the stretch over several passes (which becomes quite noisy), and digital resampling (which from 192kHz ends up being quite glitchy....)
i am wondering if recording 1bit 2.8MHz DSD is worth considering - giving me enough sampling speed to really play with resampling and slow time (i realise this will lower the pitch also....) or are there other options to consider???
what interests me most right now is getting the sound accurately slowed, so that i can understand what is happening and link it to the visuals of the film. i may perhaps end up editing heavily, or even foley-ing the whole thing, but at the moment i really want to understand what is happening sonically at very slow speeds - to be able to hear the smallest times and what is going on there....
in the past i have just recorded at 192kHz, slowed the sound down in Soundtrak Pro's stretcher, and then added transint peaks on top to preserve some of the punch that i imagine would be happening (!) this is a very old version of the project (two more itterations now), but you get the idea - 2 foot tall copper and steel boxes in mid air, wanting to get an accurate sonification of the collision....
[vimeo] 28642463 [/vimeo]
i hope someone has been playing with slow-down in this sort of range of 40 - 100x and has some possibilities worth exploring that they are willing to share. thanks, sean.