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.
Built-in timbres
The number of built-in sounds provided by the Digital Piano.
Despite the name, digital pianos are extremely rarely designed to imitate the sound of only a piano — the electronic hardware allows them to provide other timbres of sound. In addition, even the piano has its own varieties — for example, among the grand pianos there are 6 main classes, from large concert to miniature. So the built-in sounds can cover different kinds of pianos, as well as other instruments and sound effects.
The abundance and variety of timbres in digital pianos as a whole is not as great as in synthesizers, however, in this category there are very “charged” models, with a hundred timbres or more (in the most multifunctional, this number can exceed 900). However, it is worth specifically looking for a “multi-instrumental” model if you do not intend to be limited to the sound of the piano and would like to have more freedom of choice. It is worth remembering that a specific set of timbres can be different.
If the instrument is bought exclusively as a piano, then here, on the contrary, it is worth paying attention primarily to solutions with a small number of timbres. Such models are not only cheaper than "universals" — they can also sound better (due to the fact that there are few timbres and the manufacturer can carefully approach the sound quality of each built-in "instrument").
Learning mode
The presence of a training mode in the digital piano.
As the name suggests, this mode is designed to teach the game. At the same time, usually, it provides different levels of difficulty — from the most basic, for those who are just starting to master the "keys", to the advanced one, which allows you to train your technique and improve your existing performance skills. However, anyway, the principle of learning is the same: the tool independently tells the student which keys to press at one time or another. Such hints can be in the form of a backlight (see above) or as a graphic on the display. Such a method is doubtful from the point of view of classical academic learning, however, it is undoubtedly more convenient and faster than reading musical notation. Moreover, the instrument can also play the role of an examiner — launch prompts at the original tempo of the melody and check how accurately the student hits the notes.
Also note that
the learning mode requires the obligatory presence of a metronome (see below).
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.
Transposition
The ability to transpose sound on a digital piano.
Transposition is a translation into another key, when each note rises or falls by a certain number of semitones. Support for this function allows you to at least "relearn" the keyboard, which is indispensable if you need to quickly change from key to key — for example, if the vocalist does not "stretch" his part and the melody needs to be lowered by at least 1 – 2 semitones. In such cases, it is enough to turn on transposition with the necessary settings — and you can play a familiar part on the same keys without learning it in a different layout. Transposition can also be applied to built-in songs (to adjust to the key of the main part), to tracks that the sequencer works with (to mix two parts in different keys), and so on.
Fine tuning
The ability to fine-tune the digital piano for specific frequencies.
The essence of this function is generally similar to transposition — a slight shift of each note in frequency up or down. However, with fine tuning, the shift does not occur in steps (by an integer number of semitones), but very slowly and smoothly — by a certain number of hertz or even tenths of a hertz relative to the base scale. The base scale is often called "440 Hz" — this is the standard frequency of the "la" note of the first octave, according to which the rest of the scale is tuned. For a musician, fine tuning usually looks like an opportunity to set a different key frequency value — for example, 438 Hz or 441.2 Hz.
This feature can be useful for tuning the digital piano to another instrument whose frequencies change smoothly, such as a guitar. In many situations, it is easier to change the frequency settings in a digital device than to twist the strings or otherwise fiddle with complex tuning.
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.
In box
Additional items included with the instrument.
— Music stand. A music stand mounted above the keyboard, in front of the musician's eyes. Note that in this case, only the detachable music rest supplied with the portable instrument is meant (see "Body"); in stationary digital pianos, by definition, such a stand is available; moreover, it is often a non-removable part of the body.
— Pedal. Only portable digital pianos (see Body) can be equipped with an external pedal. stationary are equipped with built-in pedals. Note that there is usually only one such item in the kit, even if there is more than one input for the pedals. However, this cannot be called a serious drawback: situations where a musician needs more than one pedal are extremely rare. For more information about the inputs and the pedals themselves, see Connectable Pedals.
— Power Supply. Power supply for connecting the tool to the network. Even for portable tools, an outlet is often the most convenient way to power; and in stationary cases, other options may not be provided at all. Therefore, the power supply is an almost indispensable element of the digital piano package. The absence of such a block in the kit, usually, indicates that it is made built-in; however, this is rare.
— Disk. An optical disc (CD or DVD) containing various digital piano supplements. These can be instructions and other documentation, drivers for connecting to a computer, specialized software for edit...ing music on a PC, etc. Such a medium can be very useful if you need access to information or specialized software, but there is no Internet connection at the moment or there is a problem with it.
— Rack. Stand for floor installation of the tool. It is used only in portable models (see "Chassis") — stationary, by definition, do not require additional stands. Such a device, usually, is made folding, which provides ease of storage and transportation. Racks are also sold separately, but in some cases it is more convenient to buy a stand immediately, along with the tool.