Polyphony
The number of voices supported by the digital piano — more precisely, the maximum number of voices that the instrument can play at the same time.
This parameter should not be confused with the number of notes that can be played simultaneously on the keyboard. The fact is that in many timbres, several voices (tone generators) are used for each note at once — this is the only way to achieve a more or less reliable sound. Thus, the required number of voices can be many times higher than the number of notes — for example, the simplest chord of 3 notes may require 9 or even 12 voices. In addition, tone generators are used to play auto accompaniment parts and built-in songs (see below), and here the number of voices can already be measured in tens.
In light of all this, polyphony of less than 90 voices is typical mainly for relatively simple and inexpensive instruments that are not designed for complex tasks. The smallest number found in modern digital pianos is 32 voices. It is desirable for a more or less solid instrument to have at least 96 voices, and in top models this figure can reach 256.
Tempo change
The range over which the tempo of the sound played by the instrument can change. It can be either a built-in melody or a part recorded on a sequencer, or an auto accompaniment, a tutorial or a metronome. For more information on all of these features, see the corresponding glossary entries. Here we note that a change in tempo is often required in fact — for example, to speed up an initially "sluggish" accompaniment or slow down a training programme that is difficult to master at the original tempo.
Tempo is traditionally indicated in beats per minute. The classical, "academic" range covers options from 40 bpm ("grave", "very slow") to 208 bpm ("prestissimo", "very fast"), however, in modern digital pianos, the working range of tempos is often significantly wider.
Keyboard split
Possibility
of dividing the keyboard into two parts so that the parts of the left and right hands are played in different timbres. This allows you to simultaneously play two disparate parts on the instrument — for example, accompany a piano melody with chords from a string orchestra or organ sounds. Specific combinations of timbres are most often pre-recorded in memory, however, there are models in which the musician himself can choose timbres for each part of the keyboard.
Chorus
The presence of the chorus effect in the digital piano.
Initially, this effect was developed as an attempt to simulate the choral sound of several instruments of the same type. Even a perfect choir never plays 100% in sync, which is what the creators of the chorus tried to reproduce. This effect works as follows: several copies are taken from the main signal, which are played along with it — but not strictly simultaneously, but with a small (up to 30 ms) delay, selected randomly for each individual signal. This really allows to imitate the effect of polyphony to a certain extent, however, such sound is still far from a full-fledged choir. However, the
chorus itself is quite interesting as an additional effect.
Pitch controller
The presence
of a pitch controller(Pitch Bend) in the design of a digital piano.
Such a controller allows you to smoothly change the pitch of the note being played within a small range (usually up to a semitone up or down). In this case, control is carried out using a wheel, a lever, or another similar element that allows the musician to manually adjust the speed and limits of frequency change (including creating the effect of a note “trembling” in frequency). This function allows you to simulate the playing techniques of some instruments (for example, tightening the strings on a guitar) and gives an unusual sound to timbres that were not originally intended to have such effects.
More features
Additional features and sound customization options provided by the instrument in addition to those listed above. In this paragraph, usually, various original proprietary technologies and solutions are indicated; the specific meaning of these functions is best specified in the documentation for the tool.
Linear outputs
The number of line outputs provided in the design of the digital piano.
The line output allows you to send the sound from the instrument to external audio equipment. In this case, the sound is transmitted in an analogue format, and to play it, it is enough to pass it through a power amplifier; and active acoustics can generally be connected directly to the line output. The outputs themselves can use different types of connectors, but most often they are 3.5 mm mini-Jack or 6.35 mm Jack, compatible with most audio equipment either directly or through the simplest adapters.
Multiple line outputs allow you to connect multiple signal receivers to the instrument at once — for example, speakers with an amplifier for playback and an external recorder for recording. However, digital pianos rarely have more than 2 line outputs — more, taking into account the specifics of the use of such instruments, is simply not required.
Built-in acoustics
The power of the native acoustics installed in the Digital Piano.
This indicator directly affects the maximum volume that the instrument is able to produce "on its own", without connecting external speakers. At the same time, it is worth noting that many manufacturers go to the trick and indicate in the characteristics not the rated power (rms power when operating at full volume), but the peak power, which is the highest power that the acoustics can deliver at short “ups” of volume. Peak power values can be quite impressive — in the tens and hundreds of watts — but these figures have a very indirect relation to the actual capabilities of the speakers. Therefore, before choosing, it is worth clarifying what kind of power is mentioned in the characteristics. To do this, it is not necessary to look for detailed data on the instrument, it is enough to compare the power of the speakers with the power consumption (see below): if the claimed power of the acoustics is greater than the power consumption of the entire instrument, then the manufacturer indicated exactly the peak value.
Power consumption
The power consumed by the tool during normal operation.
The cost of electricity, as well as connection requirements, depend on this indicator. At the same time, we note that digital pianos require relatively little energy — even in the most powerful and advanced models, consumption usually does not exceed 60 watts. So in fact, power consumption data is required mainly for specific cases — for example, to calculate the total load when connecting a tool to an autonomous generator along with other devices. In addition, this information may be useful when assessing the power of the built-in speaker, for more information, see "Built-in acoustics".
