TASCAM GigaEditor 4 Manual 205
Additional PRF Tips and Consid erations
Short and Long Interval Calibration
If you are going to create both sho rt and long interval setti ngs, be aware that when a lo ng interval
is played it rst goes through the short interval lter settings and then mor phs between short and
long settings as the transposed sample exceeds the short interval and approaches the long interval.
Because the lters react in this w ay it is best to create your lo ng interval immediately ae r creating
the short interval by emphasizi ng the already existing short interval settings, this gives a more
natural sounding transition between the short and long interval co ecient values.
Fretted vs. Open Strings
When applying lt ers to stringed i nstruments and string ensemb les, open string sa mples do not
bend as well as frett ed notes since b ending an ope n string on an in strument is not oen done. In
general, the looser the performance of the original sample, the more successful the ltered
transposition becomes. i s is due in part because all t he players of the ensemble are being
transposed simultaneously, instead of with a natura l time/pitch variance per player.
Region mapping plus PRF
Another issue to consider is when s amples have already been stretc hed or transposed through
region mapping. e further you tra nspose a sample using the instrument ma pping, the less
eective the lteri ng process become s. Ideally you would wa nt an independent sam ple for each
note region of an instrument. If this is not an option, nd PRF settings for every sam ple that is
NOT transposed by the instruments region mapping and then apply those same lter settings to all
keyboard regions that contain th at sample. For instance, if a sample of C4 is ma pped to both C4
and C#4, nd the PRF settings for C4 and then apply those same settings to C#4.
Use of Body Models and Room Models
Of course the use of body models c ontributes greatly to the rea lism of programmatic portam ento,
but the use of mode led rooms also helps. Attempti ng to bend a not e as well as th e resonance of t he
instruments body a nd the frequency spectrum of th e room the inst rument was pl ayed in is quite
problematic. Solution: apply the PRF to DRY instruments and add a room model post lter…
Calibrating Decaying Instruments
A decaying sound is harder to calib rate for than a sustaining sound. When the transient sounds
dierent from the decay of a note (eg, Guitars, possibly Tim pani, GuZheng), use your expres sion
pedal to audition just the decay po rtion of a sound. Long de cays like guitars allow you t o strike a
note, gliss to the ta rget note, then fade in, cross re ferencing the t ransposed and no n-transposed
samples until you've matched not their transients, but their decay. Constant sustaining sounds, like
a steady mf on trombone, would not require this approach b ut it might help minimize distract ions
due to hearing dierent transients during cross-referencing.
Portamento Time Ranges and Tri lls
A clarinettist may lip up to a not e at the slowest speed that th e mono rule oers, almost
imperceptibly slow. On the other ha nd, at the fastest rate the glis sando is practically instantan eous.
Start with a setting of 20-30 for m ost instruments that can d o quick bends/slides. e clarinet
example would benet from a speed range of about 25-70. Settings lower than 10 are useful for
performing trills!