EmulatorII-list

There's a difference of course between bit *rate* and bit *resolution*.

EMXP natively only works with a resolution of 16 bit. WAV files with higher resolutions (e.g. 24 bit) are simply not accepted. One exception are 24-bit samples in SoundFont2 files, but the upper 8 bit part of these samples is simply ignored. This is also the standard way of dealing with 24 bit SF2 files in 16-bit SF2 engines.

Conversions between 16-bit resolutions and lower resolutions (like 12-bit in the future add-ons for Prophet2000 and Korg DSS) are simple linear conversions. But the conversion between 16 bit and 8 bit for Emax and EII is not linear: for this a unique differential algorithm is being applied.  

With respect to the play back frequency or bitrate, so far EMXP does not contain an advanced rate convertor which takes into account physical side effects of linear bitrate conversions. I didn't implement that kind of advanced convertor (yet) because the normal linear intrapolation/extrapolation method still seem to give very acceptable results.

When importing WAV files in EMXP and converting them to some target sampler format, an optimal result *could* be achieved if you would prepare the WAV files with an advanced WAV editor before importing them in EMXP. This preparation would consist of (a) convert to a samplerate which is natively supported by the sampler (like 27778 Hz for EII) and (b) convert to 16-bit resolution. In some cases (c) loudness normalization could help too - that's something EMXP will not do. 

But in general I really think that just making sure that the WAV files are 16 bit should be sufficient, EMXP will take care of all other conversion issues and so far the results are really fine. 

///E-Synthesist 


--- In emulatorII-list@yahoogroups.com, "ditabeardmemo" <brandt@...> wrote:
>
> 
> 
> Hi Esynthesist:
> 
> This actually raises a great point and is something I've been meaning to ask you. How does EMXP handle bit rate conversions from .wav and .aif to the Emulator II 8-bit format? Is there some sort of dithering involved? Will EMXP even accept .wav and .aif files with bit rates higher than 16? For example, I work in Ableton Live, which operates natively in 32-bit floating point notation, so any files I export from that and load into EMXP will be at that bit rate unless I expressly downconvert them during the render.
> 
> In short, I'm curious if there is an "ideal" workflow for prepping .aif and .wav files before converting them in EMXP to the Emulator II format. And is there a different approach for the 16-bit Emulator III?
> 
> Thanks again for creating such a great program!
> 
> Best,
> DBM
> 
> 
> --- In emulatorII-list@yahoogroups.com, "esynthesist" <esynthesist@> wrote:
> >
> > The optimizations applied in version 2.7 build 2 were only related to the compression/decompression algorithm for the Emax-I.
> > The previous version caused distortion and clicks in the sound when sounds with high volumes/loudness were converted. This was especially true in the conversion from 16-bit to 8-bit.
> > 
> > The engine for EII is still the original one. It's not the same as the Emax-I engine. The principles are the same, but the actual mathematical curves are different. I have never experienced distortion problems in the EII conversions, and I didn't receive reports on it so far, so I didn't touch it :-)
> > But actually the new curves used for the Emax now also work fine for the EII. 
> > 
> > ///E-Synthesist
> > 
> > --- In emulatorII-list@yahoogroups.com, "tomulcahy" <tomulcahy@> wrote:
> > >
> > > esynthesist, thanks for the excellent info on the various file formats. And bigger thanks for the new version of EMXP!! I've been importing soundfont format into Kontakt, and it's a joy to hear these sounds again all looped and mapped.
> > > 
> > > May I ask- what were the "optimizations" made to the EII 8 bit compressed audio format? Was this for converting from, or to?
> > >
> >
>