Mechanics
Type of action used in synthesizer keys.
— Passive. The simplest type of mechanics, when each key is, in fact, a “switch” for its note: it only turns the sound on and off, while the volume of this sound does not depend on the strength and intensity of pressing. Passive keyboards usually have unweighted, less often semi-weighted hardness (see below). Their main and, perhaps, the only advantage is their low cost, due to the simplicity of design. At the same time, the capabilities of such tools are very limited, and even when training, it is recommended to use them only at the very initial stages. As a result, passive mechanics are used exclusively in the simplest low-cost-level synthesizers, which are more suitable for the role of a toy for entertainment, rather than a full-fledged instrument.
— Active. A mechanic that provides a relationship between volume and pressing force: the harder the key is pressed, the louder and sharper the sound will be. Most often combined with semi-weighted, occasionally unweighted hardness (see below). Such keys already make it possible to control the dynamics of each note: select its volume "on the fly", highlight accents, use special techniques, etc. This feature is especially important in training, when you need to train to control the effort on each individual finger.
Active mechanics are highly recommended even for an inexpensive synthesizer, and for a mid-range instrument it is almost
...mandatory, as well as for serious learning. At the same time, many models may provide sensitivity adjustment, or even a complete switch to passive mode (for example, to simulate some instruments).
— Hammerhead. The most advanced kind of mechanics. Like the active one, it provides volume control depending on the force of pressing, but it fundamentally differs in response: hammer action is used only in weighted keyboards (see "Rigidity"), and the feeling when playing it is close to playing on a real piano. The degree of approximation, however, can be different — some models are indistinguishable in sensations from the piano, in others the mechanics are simpler. However, anyway, such features are not cheap, despite the fact that the real need for a "piano" response is extremely rare. As a result, hammer action keyboards are found mainly among top-class instruments, mainly workstations (see "Type") with full-size keyboards for 88 keys.Polyphony
The polyphony supported by a synthesizer, in other words, is the number of “voices” (tone generators) that can simultaneously sound on it.
This parameter is often described as the number of notes that can be played simultaneously on the keyboard. However, this is not entirely true due to the fact that in many timbres one note can activate several tone generators. As a result, for example, to play a chord of 3 notes in a timbre with 4 tone generators per note, polyphony of at least 3 * 4=12 voices is required. In addition, Auto Accompaniment and Preset Songs (see related sections) also use tone generators, requiring even more voices to work effectively with these features.
The minimum value for a more or less functional modern synthesizer is polyphony for 32 voices — and even then such an instrument can be used mainly for initial training and simple melodies. For a more solid application, it is desirable to have at least 50 – 60 voices, and in professional models (in particular, workstations where you have to deal with several audio tracks at once), there are models with polyphony for 150 tone generators or more.
In general, a more advanced synthesizer is likely to have more extensive polyphony, however, it is only possible to evaluate the class of an instrument by this parameter very approximately — instruments with the same number of voices can differ greatly in level. The only exception to this rule are children's synthesizers (see "T...ype"), which support up to 20 voices.
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.
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.
Learning mode
The presence
of a learning mode in the design of the synthesizer.
The purpose of this function is clear from the name. It is most often based on the following principle: the synthesizer itself tells the student which keys to press, displaying the keyboard on the display or highlighting the necessary keys using the backlight (if available, see above). Of course, at different levels of learning, the format of such prompts will also be different: for example, at the very beginning, the synthesizer highlights the necessary notes until they are pressed, and at the final stage it highlights them at the tempo at which you need to play the melody, and evaluates the accuracy of the student pressing the desired keys. There are also other features and nuances of learning — for example, the mode of separate learning of parts for the left and right hands, when the instrument itself plays one part and tells the student how to play the second. In addition, a metronome function is practically mandatory for a synthesizer with this mode (see below).
Regardless of the specific functionality, this mode will be very useful for those who are just developing their keyboard playing skills.
Tempo change
The range in which you can change the tempo of the programme played by the synthesizer — auto accompaniment, lesson tune (see above), metronome (see below), recorded sample, etc.
Pace is measured in beats per minute. Changing it allows you to adjust the speed of the synthesizer to the specifics of the situation — for example, slightly slow down the tutorial if it is too hard to master at the initial pace. The wider the range of tempo adjustment, the more options the musician has to choose from, especially in the area of very slow and very fast tempos.
Note that the traditional range of musical tempos covers values from 40 beats / min (“grave”, “very slowly”) to 208 beats / min (“prestissimo”, “very fast”), however, in synthesizers it can be more extensive — for example, 30 – 255 bpm.
Mixer
The presence of a mixer in the design of the synthesizer.
A mixer in this case is a device designed to control individual audio channels that make up the sound of a synthesizer as a whole. The list of these channels includes, in particular, the main voice, the layered voice (see “Dubbing voices”), several auto accompaniment channels (main, bass, drums, etc.). With a mixer, the musician can manually control these channels — turn some of them on and off, switch the timbre, tempo, key, etc. This greatly expands the possibilities for using the synthesizer.
Timbres layering
The ability to
overlay different timbres of the synthesizer sound on top of each other. This creates the effect of the sound of two (or even more) instruments at once — for example, piano and violin. At the same time, in advanced models, it may be possible to set different settings for different timbres so that the sameness of the extracted notes is not so noticeable — for example, the same "violin" can be set to smooth transitions between notes, while on the "piano" they will sound jerky.
Keyboard split
Possibility
of dividing the keyboard of the synthesizer into two parts, each of which is responsible for its own timbre of sound. Thus, on one keyboard, you can play two "instruments" at once in real time — for example, accompany the solo part of the violin with chords of a string orchestra. At the same time, unlike auto accompaniment (see above), all notes are taken by the musician himself, without relying on the automatic settings prescribed in the programme.
Usually, several “split keyboard” combinations are pre-written in the synthesizer’s memory, however, some models allow you to separately select a timbre for each half, at the discretion of the musician.