How to Choose a Synthesizer: Types and Features

Creativity can awaken in both young children and older individuals. It doesn’t matter what the occasion is, but the best way to start is with a keyboard instrument. Many may argue about the size of keyboards and postpone their dream, but don’t rush to a decision— a convenient and compact synthesizer could be the perfect option. Before making a purchase, it’s important to understand how to choose a synthesizer, familiarize yourself with the models of this instrument, and their features.

Which Synthesizer to Buy

Once you’ve decided on the purpose of your purchase, it’s time to learn about the different types of synthesizers. There are four main types:

  1. For beginners: These synthesizers are compact and offer a minimal number of sounds and accompaniments.
  2. Semi-professional instruments: These models include 8 octaves and more extensive possibilities.
  3. Professional synthesizers: These are more complex systems with hundreds of programs and unlimited possibilities.
  4. Digital piano: A synthesizer that mimics the classic musical instrument and produces sound only with a strong press, just like a piano.
  5. MIDI keyboard: Designed for professional musicians, it connects to a computer, offering unlimited capabilities through music applications.

Important Features of a Synthesizer

Number and Size of Keys

The number of keys on a synthesizer or digital piano affects the range in which the musician can perform. For most simple pieces and improvisation, 49 or 61 keys are sufficient. For classical music, however, it’s better to choose a model with 88 keys (7 octaves). These synthesizers will be larger and heavier, but depending on the music genre, even 37 keys may be more than enough!

Keyboard Sensitivity

Cheap synthesizers often come with keyboards where the keys offer little resistance, making playing very easy but far from resembling a traditional piano. These models are better suited for children or adults not planning to use more advanced instruments.
Models with weighted or semi-weighted keyboards attempt to replicate the feel of an actual piano, requiring more effort to press the keys. These are ideal for music school students and professional musicians. Some even feature hammer-action mechanisms, mimicking real pianos and grand pianos.

Touch Sensitivity

In traditional pianos, sound is produced through tightly strung strings. The harder you press them, the louder the sound. This adds emotional depth to the music.
Cheaper synthesizers and digital pianos often have passive sensitivity, meaning that no matter how hard you press the keys, the volume remains the same. These are suitable for amateur music performance.
More expensive models feature active sensitivity— the harder and faster you press the key, the louder and more expressive the sound becomes. This allows for emotional expression in music.
For professionals, aftertouch is also crucial—this effect occurs after pressing a key. If a musician presses a key with one force and then increases the pressure, the sound will change. This technique is widely used by professional musicians.

Split Keyboard

This feature allows you to divide the keyboard into two or more parts, each responsible for a different instrument— for example, piano and background pedals. This is essential for live performances and is supported by most models.

Pedals and Other Sound Controllers

With pedals and other sound control elements, the musician has more freedom in shaping the sound. Pedals usually function like those on a piano but can often serve other purposes, such as applying effects or changing timbre.
Pedals are often included with digital pianos, but for synthesizers, you’ll likely need to purchase them separately.
Two of the most common controllers are the modulation controller, used for smooth vibrato control, and the pitch-bend controller, for smooth pitch changes, allowing for easier imitation of real instruments and experimentation with custom-built ones.

Body

Most synthesizers and digital pianos come in compact bodies without a bottom, and they are either placed on stands (sold separately) or any flat surface. They’re easier to transport.
Some synthesizers and digital pianos come with a classic body, including an immovable stand that rests directly on the floor. These models often already have pedals attached.

Built-in Sound System

If you don’t want to constantly use headphones or connect your synthesizer to an external audio system, look for models with built-in speakers. Pay attention to the amplifier power: 2-5 watts is enough for playing in a room without other instruments, but 20 watts would suffice for small concerts.

Built-in Microphone

Synthesizers with a built-in vocoder often have a microphone included. The device is compact and its placement doesn’t cause discomfort. The sound quality is adequate for working with a vocoder.

Display

Most synthesizers come with at least a simple monochrome display showing useful information about selected effects, instruments, menus, etc. Some advanced models have touchscreens for easier menu navigation, though even professionals often prefer buttons. It’s mostly a matter of taste and habit.

Number of Tones

This is one of the most crucial parameters for a synthesizer—it indicates how many different instruments’ sounds the synthesizer can imitate. Professional models can have thousands, while simpler ones have hundreds. The higher the number, the more freedom a musician has for experimenting with compositions.
Digital pianos usually have fewer tones, as they’re primarily meant to imitate keyboard sounds, though their quality is better than in regular synthesizers.

Polyphony and Multitimbrality

Professional musicians should pay attention to these parameters. Multitimbrality indicates how many different instruments can sound simultaneously (4 or more is preferable), while polyphony refers to the total number of notes, sounds, and voices (32 is amateur, 48 or more is semi-professional, and 128 is for experts).

Auto-Accompaniment

This feature allows for automatic accompaniment within a specific style and tempo, enabling the musician to play the main melody while the synthesizer fills in the rest. The quality and quantity of auto-accompaniment styles depend heavily on the model, so it’s best to check them in advance if this feature is important to you.

Arpeggiator

This function turns several simultaneously pressed notes into a sequence, as if they were played in an arpeggio. It expands the musician’s ability to experiment.

Transpose

This function lets you shift the synthesizer’s structure by a certain number of semitones, which is useful when playing in a group, especially when parts need to be raised or lowered. With automatic transposition, you won’t need to relearn your part.

Sampling

This function lets you record your compositions and save them to the device’s memory.

Metronome

The metronome keeps time and helps beginner musicians maintain a steady rhythm.

Effects

The more built-in effects a synthesizer or digital piano has, the more possibilities a musician has for creating new sounds.
Reverb is the most common and widespread effect, and some models even support a vocoder effect, which changes the voice. The number of effects can reach dozens, but the quality in cheaper models will be much lower than in more expensive ones, even if the latter have fewer effects.

Recording Musical Compositions

Most models allow you to record played pieces in MIDI format for further editing or playback.

Ports and Interfaces

The main inputs and outputs that a synthesizer or digital piano should have are MIDI (input and output) and line (input and output).
MIDI is a special data interface/format created in 1982. It involves recording and/or transmitting information about each note and each instrument in the recording. A MIDI input allows you to control the synthesizer from an external MIDI device or transfer a melody from it. A MIDI output allows you to use the synthesizer’s keyboard (or, in particular, a digital piano, since their keyboards are often of better quality) to play another instrument with a MIDI input or record a melody.
In more advanced and modern models, MIDI has been replaced with USB connections, which enable much faster data transmission in both directions.
The line output (as well as headphones) allows you to simply output the synthesizer’s sound to an external device in analog format. With the help of the line input, any external sound in analog format can be processed with the built-in effects.
Some synthesizers are equipped with devices to read SD cards. These allow you to either expand the device’s sound library or increase the memory capacity for recording songs, sounds, and settings.

Other Features

Keyboard backlighting is essential for teaching beginners. This feature highlights the keys that should be pressed during the performance of a learning composition. While it’s not possible to learn professional playing this way, it is still possible to learn a couple of pieces.

Some modern synthesizer models have a karaoke option. These instruments usually contain a certain set of songs with lyrics, which can be expanded. Synthesizers are equipped with a jack for connecting a microphone and often include a microphone in the package.

A good synthesizer should have a USB input for connecting to other devices. Also, make sure there is a mini-jack port for headphones, so you don’t disturb your family or neighbors while playing music.