Tips For Creating Sequence Data
With a little care and forethought it is also possible to
take maximum advantage of the EX instruments’
capabilities when creating multi-track performance
setups for sequence playback.
■
Polyphony vs. Simultaneous MIDI Note-on
Timing
Although a synthesizer’s “polyphony” specification
indicates the number of notes that may play
simultaneously at the same time, this is not the same as
the number of notes which may be played via MIDI
control with precisely the same note-on timing.
For example, let’s consider a MIDI sequence in which
128 notes have exactly the same note-on timing. The
MIDI protocol usually requires about 1 millisecond to
process a single note-on command. 128 note-on
commands will thus require at least 128 milliseconds to
process completely. At a tempo of 120, this is roughly
equivalent to one 16th note! Clearly, this will result in
audible delays.
■
Minimizing Audible Note Delays
Here are a couple of techniques you can use to
minimize audible delays and general sluggishness when
creating sequences with a large number of simultaneous
note-on events.
●
Clock Shift
In a sequencer with a quarter-note resolution of 480
clocks (the EX sequencer has 480-clock resolution),
each clock corresponds to approximately one
millisecond. Keeping this in mind, it is possible to set
voices which must fall right on the beat to the precise
note timing, while the timing of voices with a slower
attack - strings, pads, etc., - can be shifted 2 or 3 clocks
later. This type of fine adjustment can go a long way
toward reducing the sluggishness of a “heavy”
sequence.
Clock shifting can be easily accomplished in the EX
sequencers by using the Play Effects feature (Manual
page 189) to individually try out different amounts of
clock shift for each track without actually changing the
original data.
●
Track Numbers
Another technique is to take advantage of the track-
processing order of the particular sequencer used. The
EX sequencer, for example, processes sequencer tracks
in order from the lowest-numbered tracks to the highest.
Thus timing-critical voices can be placed in the lowest-
numbered tracks while less critical slow-attack voices
can be placed in the higher-numbered tracks. The
overall effect is similar to the clock-shift technique
described above. Please note, however, that the
effectiveness of this technique will depend on the track-
processing order of the sequencer used for playback,
and thus may not be suitable for sequence data
destined for playback on a range of different
sequencers.
●
Playing SMF/GM MIDI Data On the EX Sequencer
NOTE
• Since the EX5, EX5R, and EX7 are not directly
compatible with GM and XG files, such files may
not play as expected.
In most SMF (Standard MIDI File) sequences, including
GM and XG files, drums are assigned to track 10 and
thus tone generators designed specifically to play back
this type of MIDI data usually give playback priority to
track 10 to ensure proper drum and percussion timing.
Since the EX5, EX5R, and EX7 are primarily
synthesizers, and have been designed for maximum
user flexibility, track-10 playback priority is not
employed. If you notice that the drum/percussion track
of SMF data sounds sluggish when played back on the
EX sequencer, try shifting the drum track 2 or 3 clocks
earlier as described in the “Clock Shift” section, above.
Part 1
Part 2
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M.D.G., EMI Division, ©Yamaha Corporation 1998
V286520 806MWIT33.2-01A0
DocumentE.qx 11/12/99 4:27 PM Page 4
