Number of keys
The greater the number of keys — the wider the range of the instrument, the lower and higher notes you can take on it right during the game, without resorting to tricks like octave shift (see below). By comparison, a full size piano keyboard has 88 keys. However, in synthesizers, such an amount is rare, because. the instrument would have turned out to be too bulky and expensive, and not every musician, even a professional one, needs such an extensive range. Thus, 88-key keyboards are used primarily in high-end workstations (see "Type"). For ordinary synthesizers, the standard is
49, 61 or 76 keys ( there are also options for
73 keys) — this is usually quite enough (while the "golden mean" option is considered to be
61 keys). And small children's models can have 32 keys.
Rigidity
—
Unweighted. Keys with a very low pressing force, literally "failing" under the fingers. This option is well suited for inexpensive synthesizers with passive mechanics (see above), but is rarely used in active models — a small resistance force makes it difficult to choose the optimal pressing force.
— Semi-
weighted. Medium-strength keys, not up to the hardness of a full-fledged piano, but showing noticeably more resistance than unweighted ones. This variant is most popular among instruments with active mechanics (see above) — the force on the keys provides adequate feedback and at the same time playing such an instrument does not cause any special difficulties even for those who previously dealt only with unweighted keyboards.
—
Weighted. Keys with high actuation force, comparable to that of a classical piano. Used only in professional
hammer action instruments (see above) — high rigidity is a must for such mechanics (more precisely, for the response that it must provide).
Built-in timbres
The number of built-in sounds provided in the synthesizer.
The number of timbres is often described as the number of instruments that a given model can imitate. However, this is not entirely true — rather, this parameter can be called "the number of instruments and sound effects." For example, the same instrument — an electric guitar — with different "gadgets" (distortion, overdrive) will sound differently, and in the synthesizer each such gadget will be considered a separate timbre. The “drums” timbre usually combines different types of drums and other percussion instruments — in other words, it allows you to portray both the “bass drum” and the cymbals without switching settings, just by pressing the desired keys. And some timbres may not have analogues among real instruments at all.
The more built-in timbres, the more extensive the possibilities of the synthesizer, the more diverse the sounds that can be extracted from it. At the same time, in high-end models like workstations (see "Type"), this number can reach 1000 or even more.
User timbres
The number of memory slots for user tones provided in the synthesizer.
For Voices in general, see “Preset Voices” above. User timbres are sound settings that were not originally provided in the synthesizer's memory and are created by the user according to their preferences. This feature is indispensable in cases where the built-in set of timbres does not contain the necessary options. However, the capabilities of the User Voices may vary from model to model. So, one instrument only allows you to edit and supplement existing timbres (for example, add a “wah-wah” effect to a bass guitar and save such a bunch as a user setting), another makes it possible to set the sound parameters almost manually, and the third even allows you to load timbres through USB (see below).
The more user timbres in the synthesizer, the more personal “instruments” you can register in its memory.
Auto accompaniment
The presence of the auto accompaniment function in the synthesizer.
This function allows the instrument to automatically play an accompaniment melody that you can play along with the main part on the keyboard. At the same time, the left hand of the musician can control the accompaniment: it is enough to take a chord on the left half of the keyboard, and the auto accompaniment will automatically “decompose” it into instrument parts that sound in accompaniment. Thus, the musician turns into a "man-orchestra": one synthesizer can replace the whole ensemble, or at least a solid part of the ensemble. Of course, the sound quality in such models can be different, and not every synthesizer with accompaniment is suitable for an event more serious than a children's party, although there are quite advanced models.
In addition, playing to accompaniment can also be useful for educational purposes: it contributes to the development of general technique, a sense of rhythm, and additional accompaniment is very convenient during improvisation exercises.
It should be taken into account that not only the sound quality, but also the number of accompaniment styles (melodies) can be different; and some models allow you to record your own melodies. See below for more details on these features.
Accompaniment styles
The number of auto accompaniment styles (see above) originally provided in the synthesizer, in other words, the number of accompaniment options available to the user.
The more extensive this set, the higher the probability of finding among these melodies suitable options for a particular case. At the same time, the abundance of styles in itself is not yet a 100% guarantee that among them there will be a suitable one, especially since different synthesizer models can differ markedly in a specific set of melodies. So the list does not hurt to clarify before buying. Also note that the situation can be corrected by user styles (see below) — many synthesizers with auto accompaniment support them.
Built-in compositions
The presence of built-in compositions in the design of the synthesizer.
This function is similar to the auto accompaniment described above — in the sense that it involves playing songs on the synthesizer itself. However, unlike Auto Accompaniment, Preset Songs play strictly by note and cannot be controlled using chords on the left half of the keyboard. In other words, with auto accompaniment, the musician has a lot of freedom, and you have to play along with melodies in strict accordance with it.
Built-in compositions can be used for a variety of purposes. One of the options is training: the musician listens to a reference recording and then tries to reproduce it, either plays along with the melodies according to the given notes, or improvises to it. In addition, in some cases (for example, at mass events), the ability to turn on the synthesizer as a player can be very useful. Also, built-in songs are used to test and demonstrate the general capabilities of the instrument: it is assumed that the recorded song can be repeated using the synthesizer itself.
Octave shift
Synthesizer support for
octave shift function.
This function allows you to shift the sound of the instrument one or more octaves up or down — for example, so that the keys of the first octave sound the notes of the second, or vice versa. This function can be used for both simple convenience and more practical purposes — it allows you to play very low and very high notes that are not initially covered by the keyboard range. This is especially useful for shortened 49- or 61-key synths that do not initially fit the full range of the piano.
Vocoder
In a very simplified way, a
vocoder can be described as a device that allows you to combine the sound of a voice with the sound of another instrument. In more detail, the vocoder allows you to transfer the properties of the voice to the signal of another timbre; in this case, the voice plays the role of a modulator, and the other timbre plays the role of a carrier. Due to this, various interesting effects can be achieved: give a live voice the intonation of a “robot”, create the effect of a “speaking” instrument (guitar, piano, etc.), supplement the performer’s own voice with a synthesized “choir”, etc. Technically, even another instrument can be used instead of a voice as a modulating signal — for example, you can combine drums with a guitar or a piano with a trumpet. However, in fact, it is the voice coming from an external microphone that is most often used as a modulator (although it would not hurt to clarify the specific functionality of this module separately).