Synthesizer vs keyboards: Look similar but are very different

Synthesizers and keyboards are usually very different but can look very similar, which causes some confusion.

In this article, I’m exploring the fundamental differences between synths and keyboards and comparing the two.

I’ll also give a basic overview of the core synth components as a guide for beginners; let’s get into it.

Why you should trust me

I started as a piano and composition student over 20 years ago.

After a short time studying classical music, I switched to jazz, and with that switch, I was introduced to the sound of jazz-funk and fusion.

I’ve been an avid synth-lover ever since, and a regular at synth shows around Europe for many years. If it makes noise, I’ve probably tried to play it.

Contents

Use these links below to navigate to the desired section of the article.

• What is a synthesizer?
• What are the components of a synthesizer?
• What are the different types of synthesis?
• What is a keyboard?
• What’s the difference between a synthesizer and a keyboard?
• Which is more cost-effective?
• Which offers better sound quality?
• Which is better for on-stage performance?
• Which is better for production and composition?
• Which should I learn first?
• Which is more versatile?
• Which has better connectivity options?
• Which is more portable?
• Which is better for beginners?
• Frequently asked questions

What is a synthesizer?

A synthesizer is an electronic instrument that uses digital or analog processing to generate various sounds.

To be more specific, synthesizers use oscillators to generate audio signals (waveforms) that then pass through various components to produce a final output sound.

Synthesizers come in several forms: synths with built-in keyboards, desktop/rackmount modules without a keyboard, and custom modular builds.

An oscillator generates a looped single-cycle waveform at a particular frequency. The frequency depends on the pitch of the note you play.

For example, playing A4 (440 Hz) will cause the oscillator to loop the waveform at a speed matching 440 Hz, resulting in an output sound matching the pitch of A4.

There are various types of waveforms; here are the most common:

• sine – the most basic,
• sawtooth – edgier with a harsher tone,
• square – edgy with a retro chiptune sound,
• triangle – similar to sine waves with more distinct character.

Components and parameters

Synthesizers often have lots of components and parameters (lots of knobs and sliders) that can be a bit daunting for beginners.

However, a basic understanding of the core components of a synthesizer will help you see things more clearly.

Along with an oscillator (often multiple) mentioned above, the core components are:

• filters,
• LFOs,
• ADSR envelopes.

Filters

A filter helps you shape the tone of your sound by filtering out parts of the sound.

It does so by cutting out designated frequencies. The most common filter types are low-pass and high-pass.

• Low-pass – cuts high frequencies while allowing low frequencies to pass through.
• High-pass – cuts low frequencies while allowing high frequencies to pass through.

Low-pass filters (LPF) are great when you need to remove harsh highs from instruments like cymbals, guitars, and synth patches.

High-pass filters (HPF) are ideal when low frequencies are causing your mix to sound boomy or muddy.

The point at which the filter cuts off targeted frequencies is conveniently called the cutoff.

A filter cutoff is something that performers regularly manipulate in real time.

LFOs

LFOs (low-frequency oscillators) generate sound waves like regular oscillators; the difference is that LFOs generate sound waves that are too slow to be audible.

We use these inaudible sound waves to modulate/affect the existing sound.

We can use the LFO to alter the sound in various ways; for example, we can use the LFO to modulate the filter cutoff.

In doing so, the filter cutoff point would move in relation to the speed (rate) and depth of the LFO, which is an excellent way to add motion to a sound.

In this scenario, the LFO would be the modulator/source, and the filter cutoff would be the destination.

Many modulation sources are available in audio synthesis, but understanding the LFO is great for now.

ADSR envelopes

An ADSR envelope features four parameters that dictate the lifecycle of each note: Attack, Decay, Sustain, and Release. Each stage of the envelope plays a different role.

Attack determines how quickly a sound will reach peak amplitude.

Decay determines how quickly a sound disappears after initial impact.

Sustain controls the loudness of a sound when a note is held.

The Sustain works closely with attack and decay – after the attack stage reaches peak amplitude, the decay will see the sound fall to the sustain level.

If you set the sustain to maximum, the decay will have no effect, and the sound will continue. The sound will fall silent after decay if sustain is set to the minimum level.

Sustain is the only stage of the envelope that is stated in volume rather than time.

Release determines how quickly a sound fades to silence after the note/key is released. That takes care of the core components of a synth.

Types of synthesis

I won’t get too deep here, but these are the most common types of synthesis:

Subtractive – as the details above describe, subtractive synthesis starts with an oscillator-generated waveform and attenuates (subtracts from) it with a filter.

Additive – creates various timbres by combining multiple sine waves of various frequencies.

FM synthesis – FM stands for frequency modulation, and it’s when you modulate the frequency of one waveform with another, creating a third complex waveform.

Modular synthesis – modular synthesis is when you create a synthesizer by combining individual component modules.

The benefits are that you can build a custom synth and control your signal path (the path the signal takes from input to output) using patch cables, but it gets expensive.

Most keyboard synthesizers have a fixed signal path, but some are semi-modular, allowing you to alter certain points in the chain.

That’s enough synth basics for now.

What is a keyboard?

We could say keyboard in reference to the black and white keys, like above when I mentioned many synths have a built-in keyboard.

But, in general terms, when we say keyboard, we mean an electronic instrument, typically with a set number of velocity-sensitive, semi-weighted keys, and there are several common types.

Electronic keyboard – typically a budget-friendly beginner instrument with 25-61 velocity-sensitive keys. An electronic keyboard will usually feature a selection of basic sounds, rhythms, and, often, interactive lessons.

MIDI keyboard – a MIDI keyboard generates no sound; it only acts as a controller for virtual instruments or external hardware.

Arranger – arranger keyboards are electronic instruments that typically have 61-88 semi or fully-weighted keys.

Arrangers have hundreds of high-quality sounds, accompaniments, and performance features. They are ideal for solo performers who want a whole band in a box.

Workstation – workstation keyboards are similar to arrangers in that they have hundreds of high-quality sounds and excellent performance features. However, they are best suited to composers and producers for studio use.

Stage piano – a high-end stage piano will usually have a synth engine inside, but for now, we’ll stick to the most basic form: a keyboard with 88 fully-weighted keys that emulates the sound of an acoustic piano.

What’s the difference?

The primary difference comes in the sound generation. While synthesizers generate sound through oscillators generating sound waves, keyboards typically reproduce sounds from samples taken from real instruments.

Using sampled sounds means keyboards can accurately mimic acoustic pianos, but synths won’t.

Synths provide far more ways to manipulate and alter sound, whereas keyboards typically work with presets and very few adjustable parameters.

Even some high-end stage pianos with a synth engine don’t have as many adjustable parameters as a dedicated synthesizer.

In summary, synths are excellent for custom sound design, while keyboards focus mainly on preset voices.

Another difference is in the weight of the keys. Synths have lightweight synth-action keys. Keyboards can have synth-action, semi-weighted, or fully-weighted keys, but a synth will never have fully-weighted keys.

Keyboards are generally far more user-friendly, while the many parameters of a synth come with a steeper learning curve.

Synthesizer vs keyboard: An in-depth comparison

In many ways, choosing between a synth and a keyboard should be an easy decision.

If you’re a performer who needs realistic instrument sounds, buy a keyboard. If you’re not sure, here are some helpful comparisons.

Cost

Synths are generally more expensive, but not in every case. Synths typically range anywhere from a few hundred to $5000, with a few exceptions.

However, a few hundred dollars budget will go much further when buying a keyboard. So, a keyboard will provide more value for money if you’re looking for all-round versatility.

Both synths and keyboards can cost thousands of dollars at the high end of the market.

Sound quality

Sound quality isn’t something we can always compare directly.

As I mentioned, keyboards sometimes sound less premium because synths generally deliver a decent quality, even at the entry-level. But that only accounts for cheaper beginner keyboards.

High-end stage pianos, like the Nord Stage 4, deliver incredible acoustic instrument sounds and world-class synth sounds.

The real question is, what type of sounds do you need?

On stage/performance

Again, the first question you have to ask yourself is what type of sounds you need most.

A keyboard is the best option if you want a wide range of ready-to-go preset sounds, including acoustic pianos.

A good keyboard will make life easier if you perform with a band that plays a varied range of music.

A synth is better if you want advanced real-time control over shaping your sound on stage and don’t need realistic sounds.

If you have a distinct sound and choose the right synth, you’ll be able to make creative decisions on the fly that you wouldn’t be able to with a regular keyboard.

Production and composition

A workstation keyboard is usually the best option for production and composition because it covers many bases.

Something like the Akai MPC is a fantastic all-rounder. Synths are great in production and composition but typically best in addition to a workstation or MIDI keyboard.

Some instruments, like the Korg Nautilus, provide a nice balance between a synth and a workstation.

Learning

A synth is the way to go if you want to learn about sound design. You can shape your sound as you like, from input to output, with many modulation options that keyboards don’t offer.

If you want to learn about music theory and playing the piano, a keyboard is always better, preferably with fully-weighted keys and a high-quality piano sound.

Versatility

Synths can be versatile, but that versatility is usually within a specific niche. Keyboards generally provide a much broader range of sounds.

Connectivity

If you’re a beginner, connectivity won’t likely be a priority. But if you’re a performer or producer, you might want to connect several pieces of equipment to trigger/modulate one device with another.

Synths generally offer more connectivity, including CV/gate, MIDI, USB, and audio in/out.

You might find similar connectivity on high-end keyboards but not beginner to mid-range ones.

Portability

Keyboards, excluding stage pianos, are typically lighter and easier to move around than a synth of the same size. The reason is that synths usually have a metal chassis rather than hard plastic.

Another reason keyboards are more portable is that most have built-in speakers, and synths don’t.

For beginners

The simple answer is that keyboards are generally better for beginners; they are easier to navigate.

However, you shouldn’t be put off by the often complex appearance of synthesizers. A solid understanding of the basics above is a great place to start, and the learning curve is worth the effort.

Frequently asked questions

Since we first started discussing synths and keyboards here at Higher Hz back in 2020, we’ve received a steady stream of questions on the topic.

To help you with the most common questions, I’ve compiled and answered the frequently asked ones below.

If you still have a question, feel free to leave it in the comments section.

Can I learn to play piano on a synth?

You can learn scales, etc., because the notes are in the same order, but without the right sound and feel, it’s not a good idea.

Can I create piano sounds on a synth?

Not realistically. Synths can generate organ sounds, snare sounds, and some other instruments, but not like a high-quality keyboard.

Do keyboards have synthesizer sounds built-in?

Some do, and some sound just as good as a dedicated synth, but you’ll rarely get the same number of adjustable parameters provided by a dedicated synth.

Are cheap synths any good?

Not always, but yes, they can be excellent. For example, the IK Multimedia Uno Synth and many of Behringer’s products.

Should I buy a hardware synth or a MIDI keyboard with synth VSTs?

It depends on your budget. Some purists will tell you that software synths still don’t compete with the real thing, but some do. To get the most value for money, buy a MIDI controller and good synth VSTs.

If you have a specific synth in mind and want to perform on stage, the hands-on workflow provided by the hardware is worth the money.

Final thoughts

As you can see, it’s less about deciding which is best between a synth and a keyboard and more about determining how you plan to use it most.

Although there is some crossover in certain areas, they are generally very different, and knowing what you need it for should tell you which one to buy.

I hope a basic understanding of synth components helps remove the misconception that synths are too complicated and encourages some beginners to get started.