Hey, So I have this urge to go through my old Goa Trance CDs from 90s and make like an ambient trance mix from them (Slow down from 150 BPM to something around 115-120).
However I am getting really bad aliasing. Actually not sure of the term, but it sounds like Cd skipping on the kick drum, sort of like downsampling actually, I am sure you know what I mean.
I tried ripping the CDs in lossless and using higher sample rate, even tough the CD is in 44 I over sampled it a bit (maybe that’s the problem).
I am not sure what to do, I am using Traktor software for now, but I would like to import them into Octatrack, but now I am wondering if that would make a difference. Maybe I have to do import them into a DAW an it will handle the slow down processing better?
“time stretch” uses complex processing algorithms to change tempo while maintaining pitch. It basically slices up audio into little snippets, stretches the snippets in time, and fills in the gaps. It will never sound transparent on full mixes.
“resampling” changes pitch and tempo by mathematically re-distributing the original audio sample points. It will introduce aliasing, and has the potential to fuzz up the hi end in an unpleasant way. The higher the original sample rate, the better the results.
The octatrack does both of these methods, but has the advantage of a stretch algorithm that takes into account the master tempo. For this reason, you get more musical results.
My advice would be that if the tracks are already destined for the OT, just feed them in raw and use the OT to do all the processing. Less processing steps is always better for sound quality.
There is however another option. In my opinion the best way to slow down a track is to print it to tape and then play back at a slower tape speed. No aliasing. The “resampling” happens in the magnetic particles, and you get that sweet tape saturation. I do this all the time on my four-track.