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.
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.
Connectable pedals
The number of pedals that can be connected to the synthesizer at the same time.
Pedals are additional controls that expand the capabilities of the instrument. One of the most famous pedal functions, familiar to many from classical pianos and grand pianos, is “sustain”, where the sound continues to sound after the key is released, slowly fading out. However, the matter is not limited to this, the purpose of the pedals can be very diverse: enabling or disabling additional effects, switching between octaves or keys, etc. At the same time, in some synthesizers, mostly inexpensive, the assignment of the pedals is fixed, in others it can be reconfigured to fit your goals.
For most instruments, one pedal is sufficient, but high-end models such as workstations (see "Type") may support multiple connections.
Operating hours
Synthesizer operating time from autonomous power supply (see above) without replacing or recharging batteries. This parameter is quite approximate, because. Actual power consumption of the instrument may vary depending on the length of the songs, the duration of the breaks in the game, the volume of the built-in speakers, the additional functions used, and other factors. In addition, the capacity of replaceable batteries can also be different, depending on the brand. However, the run time listed in the specifications gives some idea of the synthesizer's capabilities and how many sets of batteries may be needed for long-term autonomous use.
