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").
Accompaniment styles
The number of Auto Accompaniment Styles (see above) originally stored in Digital Piano memory.
Different auto accompaniment styles differ from each other in the same way that different melodies differ from each other — in tempo, time signature, rhythmic pattern, set of instruments used, etc. Accordingly, the more styles initially available in the instrument, the wider the choice of the musician and the higher the probability of finding the option that best suits a particular situation. However even numerous styles does not guarantee that among them there will be a suitable one; in addition, we note that with the same number of styles, their specific set in different instruments can also be different. However, custom styles can be provided for this case (see below).
Summarizing, we can say this: if you plan to work intensively with auto accompaniment, in addition to the number of styles, it will not hurt to clarify their specific range.
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.
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.
