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.
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.
Power consumption
Rated power consumed by the tool during operation. Modern synthesizers, even the most powerful and advanced ones like workstations (see "Type"), consume very little energy — up to 100 W, and often noticeably less. Therefore, it is rarely necessary to pay attention to this parameter in fact, mainly in rather specific situations — for example, when working from an autonomous generator, when you need to take into account the entire load connected to such a power supply.
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.