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).
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.
Arpeggiator
The presence of an arpeggiator in the design of the synthesizer.
The term "arpeggio" originally means the technique of playing a chord, in which the notes are not sounded all at once, but one after another. Accordingly,
arpeggiator, roughly speaking, is a device for the automated playing of chords using the arpeggio technique. Compared to manual playback by notes, this function is convenient because the arpeggiator can provide various additional settings: set the direction of playback (up or down), speed, interval between notes and their duration, special effects, background accompaniment, etc. At the same time, all effects work automatically, the user only needs to press the keys that make up the chord (and in some synthesizers in some modes, only one key can generally be responsible for a whole chord). The specific capabilities of arpeggiators can be different, often such a device allows you to create entire compositions just by pressing a sequence of chords.
Outputs
— Digital. Digital audio output, usually via coaxial S/P-DIF interface. It is similar in purpose to the line outputs (see below), differs only in the type of connector and the digital signal format. It can be useful, in particular, for connecting the synthesizer to a device that does not have line inputs, or if these inputs are occupied.
— USB B. A connector designed to connect the synthesizer to a computer or laptop as a peripheral device. Such a connection provides very extensive possibilities: it allows you to load new timbres, auto accompaniment styles and melodies into the synthesizer, edit existing ones; record the played music on the computer (or rewrite the music recorded in the memory of the synthesizer itself); use the instrument as an external MIDI keyboard; change various fine settings and troubleshoot, etc. The specific functionality available with a USB connection depends on the synthesizer model.
— MIDI. Output for transmitting MIDI signals (MIDI events) to external devices. MIDI is a specialized type of digital control signal used in musical instruments. Such a signal is generated when a key is pressed, it contains data about the pressing itself (duration, strength and speed), as well as the note number; Based on this signal, as well as the set settings, the electronic “hardware” of the synthesizer generates a sound of the required duration, timbre and other characteristics. Accordingly, the MIDI output allows you to transmit MIDI events to...an external device — a sequencer, sampler, another synthesizer, a computer (although it is more convenient to connect the instrument to a computer via USB), etc. This interface can be used for various purposes — MIDI recording, playing music through an additional synthesizer if the main model does not have the desired tone, etc.
— MIDI thru. An output designed to transmit to another device MIDI events received by the synthesizer via a MIDI input (see "Inputs"). In this case, the stream of MIDI commands is transmitted unchanged, pressing the keyboard of the synthesizer does not affect it. This function can be useful in some situations where the instrument is connected to several external devices at the same time. For example, if you need to control two others at once from one synthesizer, you can compose such a system as follows: the MIDI output of the control synthesizer is connected to the MIDI input of the first controlled one, and the MIDI thru output of the first one is connected to the MIDI input of the second one. Thus, the control signal goes to the first controlled synthesizer, and, through it, to the second one, while it would be difficult to connect both instruments directly.
— Headphones. Dedicated headphone output. It usually uses a mini-Jack 3.5 mm or Jack 6.35 mm connector — the vast majority of modern headphones are equipped with the first, the second is less common in the “ears”, but more reliable, and is also compatible with 3.5 mm through a simple adapter. Using "ears" when playing the synthesizer is convenient because only the musician hears the music played — this can be useful in situations where you need to practice, but it is undesirable to make noise (for example, at late hours of the day). In addition, some instruments do not have built-in acoustics, and you can listen to them normally only through additional equipment — the role of which can be played just by headphones.
Linear outputs
The number of line outputs provided in the design of the synthesizer.
The line output is used to transmit the sound produced by the synthesizer to external devices. At the same time, unlike the MIDI output, a “ready” sound is transmitted through such a connector — an analogue line-level audio signal that can be connected to another audio device — for example, to a power amplifier or active speakers for playback, to a computer or mixing console for recording, etc. Keep in mind that the line outputs can use different types of connectors — for example, 3.5 mm mini-Jack or 6.35 mm Jack; Specifically, these connectors are described in more detail in the “Inputs” section, but the matter is not limited to them.
Multiple analogue inputs make it possible to connect the synthesizer to several external audio devices at the same time — for example, to an amplifier for playback and a recorder for recording.