[linux-audio-user] Beginner sampler questions

davidrclark at earthlink.net davidrclark at earthlink.net
Wed Mar 24 19:23:35 EST 2004


Tim Hall wrote:

>               The difference is that a 
> synth that uses samples uses relatively short bursts of sound, mostly the 
> attack portion, that the ear uses to differentiate instruments and various 
> loop portions, the difference is made up with synthesised sound.
> This kind of thing exists in soundfonts, usable by fluidsynth and editable 
> with smurf/swami (in theory)

The term "wave table" refers to looking up the sequence of values in a 
table or an array, not where the samples came from nor how they were
created.  A wave table synth is a type of sampler synth.  There
is no requirement that the violin begin with a sample of the attack of
a real violin, then transform into an oscillator.  This could be done,
and the values could be stored in a table, subsequently played out
a wave table synth.  But this doesn't determine that such a synth
has the name "wave table synth."  One can record knee slaps and
put them into a soundfont, and then play them out their SB Live! card
with no synthesis anywhere in this process.  Longer notes of extended
samples can be created by looping back through the sample.  One doesn't
need to resort to synthesized sound for the remainder of a note, yet
still legitimately refer to their synth as a "wave table synth."

Chris wrote:

>              a sampler accomplishes basically the same
> thing as a wavetable synth -- it uses sound samples to generate
> tones, doing frequency shifting and interpolation as necessary.

I would recommend considering a wavetable synth to be a type of 
sampler synth.

> And as I understand it, the main difference between a sampler and
> a wavetable synth is the lack of constraints on the samples used
> -- with a sampler, anything at all could be a perfectly good
> sample, including samples of almost arbitrary duration (and thus
> size).

This is not really correct, but an implementation detail.
ALL sampler synths, including wavetable synths, have limitations
on the samples.  Now sometimes you'll see marketingspeak: "Limited
only by the capabilities of your machine."  There may be no hard-
coded limits, but there are indeed limits.

>                  But that brings my
> first question -- if you don't own/play the instruments in question,
> where do you get the samples?  I've done a lot of web searching,
> and found tons of drum loops and bass lines that are two measures
> long and so forth, but don't find much in the way of e.g. individual
> notes on basses.

When someone asks "Where does one obtain samples," many immediately
advise the questioner to go to the many sample libraries which exist,
sample CD's, sample loops, the Internet sources, etc.  One can also
record one's own samples.  One can also simulate instruments through
physical modelling.  One can also record one's own samples of 
*whatever can be sent through the audio path*.  One can mix samples,
including individual notes. For masochists, one can type in a table 
of values, convert this to an audio format, then use that as samples.
One can "rip" them off CD's, videotapes, radio broadcasts (the legality
of which depends on the source and the use of the material).  There 
are *many* sources of samples. The main limitation is the composer's
imagination.  

A simple example:  Record yourself humming into a mic.  Go into 
a WAV editor and give this a guitar envelope.  If you can, build an SF2 
font.  Now play some guitar melody.  Send it through an effects processor.
Those who have never done anything like this will learn a lot.  Now
repeat with some other sustained sound...  In some wave editors you can
keep just the envelope.  So take a spoon and tap on something.  Keep
this envelope and apply it to your humming or other sustained sound.
Rip a track of a CD and isolate one sound that you really like that is
a solo part, and edit it down to one second.  Apply the envelope to
this.  Build a font and play something.  (Specimen by Pete Bessman
can be used to do this sort of thing without having to build fonts.)

>                              you're gonna be
> spending hours and hours trying to find samples that work.

In my opinion, this is always true for great music.  You can either spend
years learning how to play an instrument, or you can spend years learning
how to sythesize, record, or manipulate samples.  Otherwise your stuff
sounds like everybody else's and/or you begin to repeat yourself.




More information about the linux-audio-user mailing list