KVR Audio

superddman · Post by **superddman** » Mon Apr 03, 2006 7:04 am

Can someone tell me what the difference between those two formats are? Hosts like Ableton Live now days can automatically detect sections in wav loops, so what is the point of REX2? Is the point only to make some extra money on licensing? Any advantages of using REX2 over WAV Loops?

Yossarian · Post by **Yossarian** » Mon Apr 03, 2006 8:06 am

Well, I guess the technical difference is that Rex files are pre-sliced so they will save you the trouble of slicing them. AFAIK, Ableton Live doesn't physically slice the audio files, I believe it's more of a granular process. It's just a different technology.

For me the main advantage of Rex files is that they can be imported into Stylus RMX, whereas .wav files can't.

/Yoss

dougsyo · Post by **dougsyo** » Mon Apr 03, 2006 11:16 am

Wav files may or may not be Acid-ized (another way of splitting).

AFAIK, only Recycle can create REX files, and you have to license the documentation to write a REX player. No such limitation on wav files.

Doug

superddman · Post by **superddman** » Mon Apr 03, 2006 11:36 am

ya, i see, so in other words, there's no big advantage when using REX2 over acidized wav.

pettinhouse · Post by **pettinhouse** » Mon Apr 03, 2006 6:31 pm

Hi,
wav loops are just playable loops without any slice for changing tempo.
with rex2 loops you can change tempo and they are compatible with many host and there are many free and comercial libraries with rex2 loops.

ciao

Andrea Pettinao

1-2-Many · Post by **1-2-Many** » Mon Apr 03, 2006 6:43 pm

Well, to put a finer point on it, REX files are sliced into sections that are moved (farther apart or closer) when you change tempo. Acidized wav loops contain tempo information for the wav, so when changing tempo the wav is stretched or compressed to meet the new tempo. Therefore, REX files suffer far less from tempo changes(no stretching artifacts) and will sound better over a larger tempo range.

Cap'n Spanky · Post by **Cap'n Spanky** » Thu Apr 06, 2006 7:29 pm

PLUS... you can change the timing of when different slices sound. In other words, you can change the groove of a rex file (not just the tempo). This is huge in my book.

Bassballjg · Post by **Bassballjg** » Thu Apr 06, 2006 8:05 pm

Actually, Acididized wav files are also sliced, and how you place the markers matters in how they play back. The markers can be edited, and often need to be to get optimized playback. At the most basic level, apps which impliment Acidized wav will let you go into the properties of the loop and specify how many beats there are in it. Incorrect information regarding the length of the audio clip in bars and beats will cause the loop to be percieved at the wrong tempo. If a loop has been stored with such incorrect information, with the markers placed wrongly or inadequately for feel, or simply left to the default values if those are not an accurate representation of the actual beat, timestreched playback will be adversly affected:

http://www.sonymediasoftware.com/news/2 ... ycode=3426

Also, there are some differences in the application of Acidization between certain apps that cause them to not necessarily recognize each other's markers properly:

http://www.soundonsound.com/sos/may04/a ... rnotes.htm

A lot of rex2's on-the-fly tweakability comes from the fact that the rex file is an object consisting of both the sliced audio and a midi file, which may be edited as midi. So it is the relative obscurity of Acid marker tweaking as general knowledge, plus rex2's midi aspect that cause this perception of rex2 being the more flexible format, when if fact both are very editable as needed.

Debutante · Post by **Debutante** » Fri Apr 07, 2006 12:37 am

dougsyo wrote:Wav files may or may not be Acid-ized (another way of splitting).

AFAIK, only Recycle can create REX files, and you have to license the documentation to write a REX player. No such limitation on wav files.

Doug

In FL you can export to ACIDized wav.

keyman_sam · Post by **keyman_sam** » Fri Apr 07, 2006 1:10 am

In sonar you can acidize loops as well. I think what he mentioned was the fact that only ReCycle can export in rex format. No other software can do it atm.

dougsyo · Post by **dougsyo** » Fri Apr 07, 2006 1:59 am

Debutante wrote:
dougsyo wrote:Wav files may or may not be Acid-ized (another way of splitting).

AFAIK, only Recycle can create REX files, and you have to license the documentation to write a REX player. No such limitation on wav files.
In FL you can export to ACIDized wav.

True, a number of programs can create ACIDized wav files, but only Recycle can create REX files.

Incidentally, there is some disagreement on what constitutes a proper ACIDized wav file, or interpretation of the spec. FLStudio creates (or used to create, not sure if it's still true) files that some players (AMG One Solo, for example) would not play correctly.

Doug

liars&ashes · Post by **liars&ashes** » Fri Apr 07, 2006 5:08 am

----Fruity Loops/FL Studio (up through version 5 at least), only adds the tempo information to .wav files, one part of Acidizing them. Although, for the record, I am not sure if any apps outside of Acid or SoundForge allow you add the key information part of the Acidization process.

Jeff

superddman · Post by **superddman** » Fri Apr 07, 2006 5:37 am

if other apps could export rex2 then I would probably choose rex2 over acidized wav. But having to rely only on Recycle for rex2, changes my mind.

1-2-Many · Post by **1-2-Many** » Fri Apr 07, 2006 6:02 am

Bassballjg wrote:Actually, Acididized wav files are also sliced

Careful, they're not actually "sliced", they contain tempo markers as you went on to describe in your post, and hence Acid files are Stretched/compressed to fit the tempo, rather than moved about like REX files, which IMO isn't ideal.

Krakatau · Post by **Krakatau** » Fri Apr 07, 2006 7:00 am

Cap'n Spanky wrote:PLUS... you can change the timing of when different slices sound. In other words, you can change the groove of a rex file (not just the tempo). This is huge in my book.

I agree...

I'm wondering actually on how accurate can be the combination of time stetching algorithm applied on REX files that have groove manipulations as main target
I knew an application called Alkali ( discontinued i think ) that was targeted on groove manipulation based with REX files, but without time-stretching algo...
I noticed ( only noticed, i'm a dinosaur still working on macos9 ! ) that a few loop-based samplers includes time stretch in their features,

what i'd like to know is how deep this concept of groove manipulation has been developped at the present time

I expect that, apart from the stretch/crunch engines, they are other simple treatments that can contribute to the purpose like changing volume or high frequencies on a single slice to modify it own character from the original groove ( smooth a previous accent and create another one somewhere else in the final, modified groove, for instance )...eventually compression/expansion applied on single slices, etc...

Difference between REX2 and WAV Loops?