Generalmusic RP-700 - Manual (Page 10)

10
owner's manual
Physical Modeling
Physical Modeling is a method of sound synthesis based upon a mathematical model which de scribes the physical construction of the
instrument being simulated. Unlike sampling technology, in which an existing sound is simply recorded at a particular moment in time,
(to remain essentially the same for ev er), the sounds produced by a Physical Model continuously react and respond to the player’s input,
maintaining all the little nuances and im per fec tions which provide the most reliable subconscious as sur ance that the in stru ment being
played is the real thing. A sampled sound can be likened to a “snapshot” of a particular mo ment in time during which an instrument is
being played. It’s like taking a photograph. The goal of Phys i cal Mod el ing is this: Instead of simply recording the final audible product
of a in stru ment like an electric piano, we replicate all the elements which are incorporated into its con struc tion. If the physical
model is constructed carefully and accurately with meticulous attention to detail, the re sult ing sound should be ex act ly like the real thing
and, more importantly, the experience of playing and interacting with the in stru ment should be similarly convincing. In the Rp 700, all
the acoustic piano sounds are created by combining sample playback with Generalmusic’s Natural String Resonance, Damper Phys i cal
Model, Ad vanced Re lease and FADE tech nol o gies, (described below). Other instruments such as RHODES, WURLI and CLAVINET are
created using pure Physical Modeling.
Natural String Resonance
This physical modeling technology, patented by Generalmusic as Natural String Resonance, allows all of the complex harmonics normally
produced by a piano’s soundboard to be faithfully re pro duced. This means that a note’s individual sound will always be slightly differ-
ent depending upon which other notes are currently being held, (and consequently which strings are un-damped and free to resonate
in sym pa thy with the note played). If you hold down a low C and let the note decay, the strings for that note are still un-damped for
as long as the key remains depressed. If you now strike another C higher up the keyboard, (stac ca to), you will hear the sympathetic
resonance of the low C strings in response to the new note played. This natural effect replicates exactly what hap pens inside a grand
piano. If you experiment with different combinations of notes you will hear harmonic colors particular to each. Because this effect is
produced by physical modeling and not by samples or DSP effects, the result is a musically and technically ac cu ra te simulation of a
piano’s soundboard and virtually infinite combinations of har mon ics can be produced.
Damper Physical Model
Another technology patented by Generalmusic is Damper Physical Model. Whenever the damper pedal is depressed, the damper physi-
cal model simulates the effect of sym pa thet ic resonance being produced by the strings which the action of the pedal has now left free
to res o nate. Use the damper pedal to hear the effect of the Damper Phys i cal Model by comparing the sounds of notes played in the
highest octave of the in stru ment with and with out the damper pedal de pressed.
Advanced Release Technology
The particular sound of a piano string being stopped by a damper while in motion is replicated by Generalmusic’s unique Ad vanced
Release Technology. Sample based electronic pi anos traditionally use a en ve lope generator to control what happens when a key is
released. This simply allows the sample loop to continue playing for a set period of time until its amplitude is finally reduced to zero
by the envelope generator. In an acoustic piano, vibrating strings are silenced when a felt damper comes into contact with the moving
string. When this happens, depending on how hard the key was struck and the length of the string itself, certain frequencies are damped
earlier than others while some other frequencies are even accentuated, (anyone who ever studied how to produce harmonics on a
guitar will recognize this principle). This produces a distinctive harmonic “ring” as the different fre quen cies in the string’s tone dis si pa te
through out the piano soundboard. This Advanced Release Tech nol o gy in the Rp700 series simulates these phe nom e na with complete
accuracy throughout the 88 note range.
FADE - Filter Algorithm Dynamic Emulation
Reproduction of the complex harmonic and dynamic changes which take place as you increase or de crease the velocity of a key-strike
on a piano have always presented a serious problem for traditional sam ple-playback tech nol o gy. The only practical way to re pli ca te
these changes has been to select three or four distinctly dif fer ent levels and switch between these according to the velocity with which
the key is struck. This produces the unnatural effect of having clearly audible steps between different velocity levels, further
diminishing the authenticity of the sound reproduction. Unlike the velocity-switching meth ods used in other elec tron ic pianos, Gener-
almusic’s unique FADE technology utilizes only one specially configured sound source per note. At the heart of the FADE engine is a
extensive database which can be used to look up the precise harmonic content of any note played at any velocity level. Whenever a note
is played, the FADE engine analyzes the velocity of the key-strike and constructs, in real-time, a model of the nec es sary har mon ic con tent
for that particular note played at that velocity. The note’s sound source is pro cessed by the FADE engine with appropriate harmonic
content being added or subtracted ac cord ing ly. In practice, FADE tech nol o gy provides seamless transition from pianissimo all the way
through to for tis si mo for each note without any audible switching.
TECHNOLOGY
The Rp 700 is powered by Generalmusic’s break-through technology DRAKE.
DRAKE (Dsp-Risc-Advanced-Keyboard-Engine) is the ultimate DSP: probably the most advanced piece of musical hardware in
the world. Its 32-bit and 50-MIPS internal structure and its totally programmable software architecture make this processor so
fast and powerful that any kind of algorithm, from Wavetable to Physical Modeling, can be implemented in real time, either
in generation or in post-processing. Using the Physical Modelling power offered by DRAKE, Generalmusic has created and
patented a number of new algorithms which replicate some of the world’s most famous vintage instruments like Rhodes™,
Wurlitzer™ and Clavinet™. DRAKE has found unanimous, enthusiastic appraisal from experts in these fields.