EXS 24 Logic Sampler Users Group

Very New to exs and logic, and I am frustrated at the documentation 
which seems to tell more "what" than "how to". I'm running exs24 MKII 
on logic 5.5, Mac powerbook OSX with 1Ghz processor and 1GB RAM.  

The main point which I need clarifying on: when I try to import a 
sample into a new sampler instrument, is it possible (for instance 
with the samples that came with the exs) to make a sample sound at 
every pitch on the keyboard?  When I have tried to import a sound 
(clean guitar) the sample slows down as you lower the pitch, and 
speeds up as you play higher on the keyboard.  Is this the exs's way 
of approximating the pitch via sample speed?  Do I need to purchase a 
sample that has every note of the keyboard sampled seperately or can 
I make the exs24 force a single sampled note to play at each pitch?
(I noticed that the "clean guitar" that came with the exs24 has many 
seperate notes sampled, but not all of them- )

Not sure if I explained that correctly, but I hope someone gets it!

Thanks! Peter

At 10:27 PM 3/27/2003 +0000, you wrote:

>The main point which I need clarifying on: when I try to import a
>sample into a new sampler instrument, is it possible (for instance
>with the samples that came with the exs) to make a sample sound at
>every pitch on the keyboard?  When I have tried to import a sound
>(clean guitar) the sample slows down as you lower the pitch, and
>speeds up as you play higher on the keyboard.  Is this the exs's way
>of approximating the pitch via sample speed?  Do I need to purchase a
>sample that has every note of the keyboard sampled seperately or can
>I make the exs24 force a single sampled note to play at each pitch?
>(I noticed that the "clean guitar" that came with the exs24 has many
>seperate notes sampled, but not all of them- )
>
>Not sure if I explained that correctly, but I hope someone gets it!
>
>Thanks! Peter

Just check the box for disable pitch in that sample's zone.

Colin Miller

On a fine day, 27-03-2003, s007ing wrote:

>The main point which I need clarifying on: when I try to import a
>sample into a new sampler instrument, is it possible (for instance
>with the samples that came with the exs) to make a sample sound at
>every pitch on the keyboard?  When I have tried to import a sound
>(clean guitar) the sample slows down as you lower the pitch, and
>speeds up as you play higher on the keyboard.  Is this the exs's way
>of approximating the pitch via sample speed?  Do I need to purchase a
>sample that has every note of the keyboard sampled seperately or can
>I make the exs24 force a single sampled note to play at each pitch?

Not sure if I understand you fully, but it sounds as if you're a bit 
confused as to what samplers do.  What you describe is exactly what 
_every_ sampler does: a recorded note is played back at original 
pitch/tempo at a certain key (like C3), and if you stretch it across 
the keyboard, higher notes will play a higher pitch by speeding up 
the sample -- and thus shortening it.  Ditto in reverse for lower 
notes.
So a 1 second sample, assigned to "original key = C3" will last only 
half a second when you play C4 and 2 seconds when playing C2.  That's 
the basic principle of sampling and there's little you can do about 
that.

In order to avoid ugly artefacts you thus indeed need several sampled 
pitches -- that's one of the reasons e.g. orchestral libraries 
provide every single note instead of just one.

What you're after is a kind of realtime "pitch change without 
time-stretch".  There is software that achieves this, but note of 
those is (afaik) realtime, since the algorithms involved are rather 
complicated.  Logic's own built-in "Time & Pitch machine" is an 
example of a piece of software that will let you do exactly this.

-- 
Hendrik Jan Veenstra  <h@...>
Omega Art: http://www.omega-art.com

Hendrik Jan Veenstra <h@...> wrote:


>
> Not sure if I understand you fully, but it sounds as if you're a bit 
> confused as to what samplers do.  What you describe is exactly what 
> _every_ sampler does: a recorded note is played back at original 
> pitch/tempo at a certain key (like C3), and if you stretch it across 
> the keyboard, higher notes will play a higher pitch by speeding up 
> the sample -- and thus shortening it.  Ditto in reverse for lower 
> notes.
> So a 1 second sample, assigned to "original key = C3" will last only 
> half a second when you play C4 and 2 seconds when playing C2.  That's 
> the basic principle of sampling and there's little you can do about 
> that.
>
> In order to avoid ugly artefacts you thus indeed need several sampled 
> pitches -- that's one of the reasons e.g. orchestral libraries 
> provide every single note instead of just one.
>
> What you're after is a kind of realtime "pitch change without 
> time-stretch".  There is software that achieves this, but note of 
> those is (afaik) realtime, since the algorithms involved are rather 
> complicated.  Logic's own built-in "Time & Pitch machine" is an 
> example of a piece of software that will let you do exactly this.



While I agree with nearly all of the above there are already some realtime
samplers/audio processors that do this.  Probably Celemony (I have only heard
the demos) and definitely Native Instruments Kontakt will do this for example. 

Kontakt doesn't do it very well though -- there are loads of obvious artifacts
as when operating in this way it uses a granular synthesis approach to achieve
pitch shifting without changing playback time. You wouldn't want to do this
with acoustic instrument samples unless you wanted to mangle them. 

I think we can expect this capability to become increasingly common now that
conventional software samplers are just about a dime a dozen and the processing
power is almost there now to do just about anything that DSP systems are
capable of -- eg physical modelling instruments etc -- just not all at once. 

Regards,
Murray

Thanks all for your replies- you confirmed what I had thought, that I 
need every note sampled seperately to avoid the sampler "time-
stretching" the sound to achieve pitch change.  And since I am going 
to use mostly acoustic instruments, the direction I hear from you all 
is that using various software to "force" pitch change from a single 
note sample is not an attractive option.  

Thanks again!
Peter

harmony@... wrote: 
>
> Thanks all for your replies- you confirmed what I had thought, that I 
> need every note sampled seperately to avoid the sampler "time-
> stretching" the sound to achieve pitch change.  And since I am going 
> to use mostly acoustic instruments, the direction I hear from you all 
> is that using various software to "force" pitch change from a single 
> note sample is not an attractive option.  


Yep -- the best sample sets available are multi-velocity sets where every note
is sampled. Hence the pianos with upwards of two gigabytes of samples. 

One essential thing about acoustic instruments is that every note has, to some
degree, a different quality.  For example,  stringed instruments like guitars
and violins have a set of narrow Q resonances which boost particular
frequencies. Historically, violin makers strove for consistency of tone but the
beauty of their instruments' tone is tied up with the note by note variation.
The consistency they strove for (the sort you can get with a synthetic
instrument and an electric pickup) is boring to listen to.  

If you grab a sample of one note and pitch shift it to cover a range, some of
the instrument's tonal character is lost -- character that would be evident in
a note by note sample set. There is also an unnatural quality about the
instument you have created since the resonant frequencies move about with the
transpositions. 

Regards,
Murray

> From: s007ing [mailto:harmony@...]
> 
> Thanks all for your replies- you confirmed what I had thought, that I 
> need every note sampled seperately to avoid the sampler "time-
> stretching" the sound to achieve pitch change.  And since I am going 
> to use mostly acoustic instruments, the direction I hear from you all 
> is that using various software to "force" pitch change from a single 
> note sample is not an attractive option.   

Even worse - if you want convincing acoustic instrument sounds, you probably
need several samples per note, for different velocity levels, and maybe
some articulation differences tied to other MIDI controllers, etc.
Check out some of the BIG BIG BIG gigasampler instruments, that's
why they sound so good...

	-smeet