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Last Changed
01/19/2005
SoundFont® Bank Tips
- Don't stick to only using your Global Loop
points. By changing the Local Loop point of a sample in the
Instrument Pool, you can transform a single waveform into several
variations simply by changing the start or end loop point. For example, if you
are using a perfectly looped Sine wave that sounds smooth and flowing, you
could move the Local Start or End loop points (not both) away from the perfect
loop point, and this will add some grunginess to the Sine wave. This
way you can use a single Sine wave sample to create a small palette of waveforms
which vary between Sine and something similar to Sawtooth. Watch your tuning because once you move away from the
perfect loop point, the tuning of the sound changes and you have to manually
retune it. This is relatively easy to
counter ... if you make the loop smaller (Start and End move closer together),
than the pitch of the sample will increase and you need to lower the tuning.
Conversely if you move the Start and End points further apart, the pitch of the
sound will lower and you will have to increase the tuning of your instrument.
- When you sample your sounds, don't normalize
(maximize volume) them to 100%. Rather keep them between 85% and 95%, so that
you leave a little headroom for the hardware or software which is playing them
back. Some soundcards distort easily if the sound overburdens the card, so if
you keep the level a little lower, this always helps prevent harsh clipping
and distortion.
- There are some samples you just cannot loop well.
Don't make it your life's ambition to loop them if it seems impossible to do
so. If you
can possibly generate the sound again and force it into a pattern which
promotes easy looping, then do this. If you have no other recourse, decide if
the quality of the loop is acceptable and make a decision to keep or throw it away.
If you can, fire up an editor and attempt to create the sample yourself, with
better looping possibilities, otherwise you create a sub-standard SoundFont
and pollute the already-cluttered SoundFont arena.
- When sampling sounds off other machines, it is always
a good idea to try and keep modulation properties (LFO, vibrato, tremolo) to a
minimum if you want to be able to loop easily and save RAM. Some sounds don't
work without keeping the original LFO settings, and in these cases you really
need to do some heavy multisampling. However, if the sound relies on
properties you can replicate in Vienna, then turn them off on the original
machine. It makes the sound a lot easier to loop and masks weird sounding
changes as you move up and down the keyboard.
- What about some general tips and information using
the SoundFont format to it's maximum ...
1. First thing to do is create multi-sampled waveforms, like sawtooth,
square, triangle, sine, noise, and various pulse-width waveforms (10%, 20% 30%
... etc). This gives you a basis to work with. You can use some freeware
waveform editors for this task, such as Cool Edit or Sound Forge.
2. Next, take the samples and invert them, so you now have a palette of
normal waveforms as well as their inverted counterparts.
3. Load these into your sampler and loop them. Looping the inverted
waveforms should be easy, since the loop points are identical to the original
samples.
4. When layering your waveforms into a preset, always try to use at least
2 layers and detune them slightly, or apply different pitch LFO's to each.
This gives that chorussy effect so prevalent in multi-oscillator analog synths.
If possible, apply different settings for each layer, so that their LFO's are
slightly different, their tuning is slightly different, the filtering is a bit
different ... etc. This allows for a more evolving and unpredictable sound
that simulates an analog synth.
5. Sawtooth and Square waves are always your best choices when emulating
analog sounds because they are at the heart of analog synths.
6. Layer a normal sample with it's inverted counterpart. Under normal
circumstances this will actually output no sound as the opposing waveforms
cancel each other out (not on the inaccurate SB Live! though). However, detune
them slightly and you'll get yourself a pulse-width waveform . Set your
Modulation wheel to modulate the pitch of one of the waveforms, or the pitch
LFO of one of them (very slowly), and you can control the pulse-width in real
time. Actually, setting a controller to modulate amplitude, filter cutoff, or
filter rez also has interesting results.
7. Take a waveform and set the Local Loop point off by a few samples. This
works well with Sine waves because you get a completely new sounding waveform
when the sample loop is inaccurate. The more you offset the loop point , the
more the Sine wave approaches the sound of a Sawtooth waveform. However, the
more you offset the loop-point, the more the waveform plays back out of tune
so you'll have to adjust for this.
8. When layering samples, try layering one an octave lower than the
other. This can really phatten up the sound and this is particularly good for
bass sounds.
9. Another trick related to point 8 is to layer a Sine wave one octave
lower than whatever sound you are creating. You can get a super stacked, phatt
sound by doing this because it adds a lot of low-end ballz to the sound. It
can be pretty roof-shaking if you work the sounds a little.
- I have written a very simplified article on emulating
analog synths, and you can find this right
HERE - the article is
called Vintage Synth Emulation on a Sampler. It's old, but still useful
for giving one a simple idea of how things work, and from which direction to
approach analog emulation of samplers.
There's also an article on creating waveforms in Visual Basic which, although
not quite what we're looking at, can still make interesting reading if you are
so inclined. You can also find this
HERE under Wave
Modulation Synthesis for Programmers.
One thing I can add to the 6 basic waveforms previously is the use of more complex waves.
For example, if you have access to software which can generate additive, AM,
FM, or other types of waveforms (Cool Edit and Sound Forge are good
candidates), this
enhances your sound palette much further, allowing you to create some of those old
ring-mod sounds as well as DX and other FM sounds. It helps create some
crispy bell-like textures, and clangourous noises, clangs, and clashes. Since
samplers often don't have access to real time synthesizing (like ring-mod, FM
... etc), the only way to get this into your sound is to include these types
of waveforms. With Additive, AM, and FM, it is relatively easy to create
simple waveforms which can be looped easily, but result in an overtonic (yes,
I know, no such word!) sound. It's great for pads if you dub this over your 6
staple waveforms. Also, nothing creates bass sounds like FM can. I know,
analog synths are supposed to be bass kings, but it's just not true - FM
synths are capable of bass sounds that a Moog only dreams of being able to
create!
- The SoundFont 2.0 standard is quite limited when it
comes to getting real time interaction out of your SoundFonts. The lack of
Portamento, multiple filters, LFO shapes, and controller routings forces you
to be very creative when trying to get unconventional sounds, or when trying
to create something that hasn't been done before. Soundfont format 2.1 is much
more capable, but is not available on anything but the Emu ASP and Creative
Labs Audigy soundcards.
One of the methods previously mentioned, and one we have used for quite some
time, is to layer inverted versions of the same sample on top of each other.
You will be surprised at how much this can phatten up a sound, or how much
livelier you can make it.
Since the samples essentially cancel each other out in a perfect soundcard
(the SB Live! does not), you have no sound until you start messing with the
parameters of one of the inverted samples. The avenues you can take are as
follows:
1. Change the Resonance setting of one of the samples. This brings in a
filtering effect similar to a high-pass filter, where certain frequencies of
the untouched waveforms begin to show through. It's not an epiphany, but it
does widen your sound creation palette by giving you another way to drag yet another sound
from a single sample.
2. Change the filter cutoff of one of the samples. This again brings
out various frequencies as the sound-cancellation properties of the inverted
samples are messed with. It works in a similar manner to changing the
resonance of one sample (point 1 above), but the sound is different - just another way of changing the tonal characteristic of a sample and getting
more use out of it.
3. Detune the samples. This allows you to employ a pulse-width of sorts
- the more the detune, the bigger the width. You can use this method to change
layered Sawtooth-Inverted samples into a pulse width of between 0% and 100%,
so once again you stretch the sonic potential of a single sample into many
different timbres.
4. Change the volume of one of the samples. Again, a similar effect to
the above, but just different enough to give you a few more timbres from a
single sample.
5. Use different ADSR settings. If your inverted samples have different
Attack, Decay, Sustain, and Release settings, you can get various pulse-width
effects based on whether you're applying different Amplitude, Pitch, or Filter
ADSR envelopes. You can get some quite interesting effects this way.
6. Use the LFOs to give you a more consistent variation to point 5
above. You can have a consistent rate of pulse-width change, for example, but
applying a pitch LFO to one of the inverted waveforms.
7. If you have access to the true Soundfont 2.1 standard, try routing
velocity to, say, the pitch of one of your inverted waveforms. This will
increase the pulse-width the harder you press your keys. Aftertouch is even
better in this regard because the harder you press down a key, the more
pronounced the PW effect. Once you have access to the full spectrum of
controller routings, Soundfonts take on a new life and can be extremely
expressive because you can vary all sorts of parameters based on controllers
such as a modulation wheel, expression pedal, all manner of knobs and sliders,
velocity, aftertouch ... etc. The possibilities are mind-boggling.
 
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