Comparison Roland JD-Xi vs Roland GAIA SH-01

The size of the keys of the synthesizer — primarily in width.

— Full size. The keys are standard size, the same as on a piano keyboard. Such keyboards are designed for an adult and are used in almost all synthesizers that are not related to children.

— Small size. The keys are reduced in comparison with the standard width (and often also height). Practically not used in "adult" synthesizers, but they are almost mandatory for children's models (see "Type"). On a full-sized keyboard, some features are not available to a child (for example, chords with far notes), and small keys designed for a child's hand can correct the situation.

— 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).

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.

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.

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.

The presence of the transposition function in the design of the synthesizer.

Transposition is the translation of a melody into another key — for this, each note rises or falls by a certain number of semitones. This feature allows you not to relearn the part when switching to another key — just reconfigure the synthesizer and play familiar keys. In addition, transposition can be useful, for example, for mixing parts originally played in different keys, for translating the auto accompaniment into a key that is more convenient for playing the main part or singing, etc.

The presence of a modulation controller in the design of the synthesizer.

This function allows you to give the sound the effect of vibration, "trembling" — when the note does not sound at a constant volume, but unevenly, with alternating peaks and dips in volume. This effect makes the sound more alive, gives it a resemblance to the performance on a real instrument, and is also often used as an artistic device.

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).

— mini-Jack (3.5 mm). Line-level analogue audio input using a 3.5mm mini-jack. The line input itself is used to connect an external analogue audio signal to the synthesizer — for example, from a computer sound card. The use of such a connection can be different: playing accompaniment through the built-in speakers of the instrument, switching the signal to an external amplifier with “mixing” the sound of the synthesizer itself into it, etc. Specifically, the 3.5 mm mini-Jack connector is small in size, it is popular mainly in portable equipment and inexpensive stationary devices — “serious” audio equipment is usually equipped with more reliable connectors, like Jack (see below). As a result, an input with this type of connector is typical mainly for entry-level synthesizers.

— Jack (6.35 mm). Line-level analogue audio input using a 6.35 mm jack. By purpose, such an input is completely similar to the input with a 3.5 mm mini-Jack jack described above, however, the Jack connector is larger, provides a more reliable and high-quality connection and is considered more suitable for stationary audio equipment, especially high-end ones. Therefore, in synthesizers of an average and advanced level, usually, this type of line input is used. At the same time, we note that a 3.5 mm plug can be connected to a 6.35 mm jack using a simple adapter.

— Digital. Input for connecting to a digital audio signal synthesizer. It is similar in purpose to the linear interfaces descri...bed above, but differs both in signal format and in connector type — most often it is a coaxial S / P-DIF interface using an RCA connector, although other options are possible. Digital outputs are quite popular both in professional audio equipment and in home appliances like PCs and even TVs, so such an input may be useful.

— MIDI. MIDI is originally a digital signal format used in electronic musical instruments. Each key pressed on the synthesizer gives just such a signal: it contains data on the duration, force and speed of pressing, as well as the note number, and based on the control signal (MIDI event), the “hardware” of the synthesizer generates the desired sound. Accordingly, the MIDI input allows the synthesizer to receive MIDI events from external electronic musical devices — other synthesizers, MIDI controllers, etc. This connection can be useful, for example, if the external instrument does not have the desired timbre; in addition, many synthesizers are capable of recording received MIDI signals. In some cases, the possibility of switching such a signal via MIDI thru may also be useful (see "Outputs").

— USB (type A). A classic USB connector that allows you to connect various external devices to the synthesizer — primarily flash drives and other drives, other peripherals are rarely supported. The features available when working with a flash drive depend on the general functionality of the synthesizer and may be different in different models. So, some instruments are capable of playing music from such a carrier, which plays the role of accompaniment for the main part — this can be more convenient than using auto accompaniment. Others are able to record music on a flash drive. It may also include updates to the Voice Set and/or Auto Accompaniment Styles (see above), firmware updates, etc.

— Card Reader. A slot for reading memory cards, most often SD: this is a universal format widely used in many types of modern electronics. Like a USB flash drive (see above), the card reader can be used for different purposes — most often for playing musical accompaniment or recording music, but there are other options (loading additional timbres, updating firmware, etc.).