You are here

Spliced Audio vs Unspliced Audio processing

For everything after the recording stage: hardware/software and how you use it.

Spliced Audio vs Unspliced Audio processing

Postby Elephone » Thu Nov 14, 2019 9:36 pm

Hi. I've been using Propellerhead's Recycle to alter the tempo of (dry) drum multitracks (High-Hats, Snare, Kick) without using time-stretch algorithms (which distort the natural envelopes).

Basically, if the drum track is slowed down, Recycle adds a little of the reversed audio from the tail ends and crossfades it to extend the sound of a cymbal that may otherwise not reach the next hit, for instance. However, problems arise with things like cymbal crashes and other sustained sounds, since it's not possible to split up a continuous sound without leaving obvious gaps. So, I either use time-stretching (using Adobe Audition) on those short sections, or simply substitute a section without a crash, and add a crash hit over it. (Why some loop libraries include loops with crashes is beyond my comprehension!)

Anyway, in the past, I usually saved the re-tempo'd audio as continuous [.WAV] files, but I've realised that [.Rex2] files are basically ready sliced audio that can be manipulated and altered, and have AHDSR envelope filters applied, etc. This is useful, because if you slow down a drum track, it probably would benefit from the 'groove' or 'feel' being altered, as real drummers wouldn't play the same way at slower tempo. Pitch can also be altered using re-sampling as opposed to algorithms.

So there are a few things I'd like to know before going any further:

1. What are the best programs now available to import [.Rex2] files?

I'm assuming Kontakt 6 is more advanced and flexible than Reason 4, but I get the impression Kontakt doesn't add reversed audio to fill in gaps when tempos are slowed. I presume there are some other DAWs and programs that can do things that others can't. Is there a sequencer with AHDSR envelope filter that can import [.Rex2] files but is limited to the virtual keyboard (of 88, 92 or 99 keys) as a limit on splices?

Reaper can import [.Rex2] files and alter the position (quantising, regrooving) and pitch of slices (by either re-sampling or timestretching). However, because the slices are not loaded into a player, no reverse audio is added to tail ends, and you cannot apply AHDSR envelopes to slices, as far as I know. Hence the following question:

2. What are some of the other advantages/disadvantages of working with sliced audio in terms of processing -vs- using gates & compressors on continuous audio?

I mean, applying a AHDSR envelopes to slices -vs- using gates & compressors on an unsliced continuous audio file. Apart from the non-destructive re-tempo-ing and resampling pitch-shift options, I mean.

3. What are best 're-groove' programs for adding swing and alternative rhythmic feels to MIDI notes?

Reason 4 has a ReGroove engine that intercepts the MIDI data and add grooves and velocity alterations based on actual drummers and drum machines, but it's over 10 years old and the ReGroove options don't appear to have changed in recent versions I've looked at on YouTube.

However, Reaper is also able to import [.Rex2] files ...and of any length, so is not limited to the 92 slices of Reason's DrOctoRex loop player (which is limited to the number of keys available on a virtual keyboard, at least in Reason 4). Reaper also has many of the 're-grooving' options available in Reason (and any others can be captured from Reason by simply saving a bit of MIDI with that ReGroove patch applied and capturing the groove in Reaper from that MIDI file).

There are also programs like Accusonus ReGroover that allow you to work with unsliced audio loops of 30 seconds or less, and turn them into multitracks. And I presume there's lots you can do in Melodyne, which I'd use if you were able to turn off time-stretching and simply use resampling where you want. I mean, Melodyne and programs like Regroover are able to detect the start and end points of audio events and move them about(!)... so why does it not allow you to simply stretch or shrink tempos without affecting the integrity of the hits?

Note that, you can always finish editing a loop in its desired tempo in Reaper, alter grooves, etc, and save it as a [.WAV] file in its original tempo, then re-import it into Recycle, then alter tempo so that you get the reverse audio effect joins between hits. Or mix it with a timestretched version and gate the tail ends in... best of both worlds perhaps.

Anyway, I hope this will be of use to others. I'll be looking into it too, but I know many people work with loops and MIDI, so you've probably learned everything there is is know in terms of what can be done. I'm struggling to hold all the different factors in my head at once as I'm quite new to MIDI based music making.

Thanks in advance.
Elephone
Frequent Poster
Posts: 1150
Joined: Wed Feb 11, 2009 1:00 am

Re: Spliced Audio vs Unspliced Audio processing

Postby Elephone » Fri Nov 15, 2019 7:12 pm

Had a look at Ableton Live, but it doesn't really appear to do anything that Reason 4 can't do in terms of MIDI re-grooving. I take it Reason 10 can automatically create [.Rex2] files out of [.WAV] files now, so perhaps Ableton is able to do that too(?)

The problem with Timestretch algorithms is that it's not clear to me what effect it has on further processing, and I suspect people have become so accustomed to the digital artifacts (due to use of autotune) that many people don't mind it.

When it comes to drums and percussion, I just think software like Melodyne should favour resampling as a primary means of pitch shifting, and use auto splicing as a means of re-tempo-ing audio, thereby preserving the integrity of original audio events .
Elephone
Frequent Poster
Posts: 1150
Joined: Wed Feb 11, 2009 1:00 am

Re: Spliced Audio vs Unspliced Audio processing

Postby Elephone » Mon Nov 18, 2019 7:48 pm

Incidentally... Reaper seems to struggle with long [.Rex2] files. When it goes into the background, it takes a while to restore them in the edit window when you click on it again.

Anyway, my real interest in 'regrooving' specifically, is not actually to alter the drum kit multitracks I recorded years back, but to affect drum machine rhythms. If it were just drum kit, I'd re-tempo them in recycle, maybe make a few manual tweaks. Obviously, if I've spent a lot of time getting a drum kit to sound right, recorded it onto quality tape, applied effects, then brought back (through far better AD converters than I generally have access to)... it can make sense to re-use them, for certain styles of music anyway.
Elephone
Frequent Poster
Posts: 1150
Joined: Wed Feb 11, 2009 1:00 am


Who is online

Users browsing this forum: No registered users