If you’re looking to buy your first synthesizer or you simply want to learn more about how synthesizers work, you may have heard the terms ‘monophonic’ and ‘polyphonic’ floating around.
Although synths fall into many different categories and classifications, a synth is almost always either monophonic, or polyphonic – which each type having their own set of benefits and drawbacks.
(There are also such things as ‘duophonic’ and ‘paraphonic’ synthesizers, but these are not commonly used and are technically considered polyphonic.)
Anyway, let’s look at both monophonic and polyphonic synthesizers in more detail.
What Is A Monophonic, or Polyphonic Synth?
Quite simply, it comes down to how many notes or keys your synthesizer can play at one time.
A monophonic synth can only play one note at a time. A polyphonic synth on the other hand can play multiple notes at one time – most commonly up to 4, 8, or 16 depending on your synthesizer.
However, there is another important point to understand about monophonic synthesizers.
Despite only being able to play sound from one key at a time, a mono synth can have multiple oscillators – the component that generates the waveforms. Many synths allow you to shift the pitch of the oscillator – for example, up or down an octave.
If, for example, you left one oscillator normal and then had the other oscillator play an octave lower, this would play two different pitches despite being a monophonic synth.
Now you may be asking yourself, “why would anyone choose a monophonic synthesizer?”
The truth is, there are benefits that monophonic synths have over polyphonic synths, which I’ll get into in a moment.
The Advantages Of Monophonic Synths
First and foremost, the biggest difference you’ll see right away is in price.
With polyphonic synthesizers, many of the same internal components need to be duplicated for each additional voice – at a bare minimum, the oscillators, vcas, filter and envelopes. This leads to higher overall manufacturing costs and a pricier synth for us.
Monophonic synthesizers on the other hand allow you to get a higher quality piece of gear for the same price. Polyphonic synths may make sacrifices in order to stay affordable, unless you’re willing to spend a lot of money.
One such example would be a decrease in the number of modulation effects, or ways to shape the sound. Those who enjoy experimenting with sound design may prefer monophonic synthesizers, as you can generally get a lot more for the price.
Monophonic synthesizers are also more likely to have sequencers and appregiators built-in, which are very useful (and fun to play around with!)
For many people looking to get their first synthesizer, price is the most significant difference.
2. Sonic Differences
All else being equal, the electronics of a mono synth allow it to sound slightly sonically better than an equal poly synth. The degree of this difference is up for debate however, and many inexperienced synth players probably won’t be able to tell the difference.
The reason has to do with the gain and amplification of the note.
When gain is too high, part of the waveform gets ‘chopped off’, leading to a distorted sound. In some cases on some instruments, this is desirable (think an electric guitar playing rock music.) However, we have to be in control of this and be doing it intentionally, of course!
On a polyphonic synth, there needs to be extra headroom available to account for the extra voices – this way, even if you played all of them at once, the signal still wouldn’t start distorting. This is created by lowering each individual voice, so even if all of them are played together, the synth doesn’t run into issues.
On a monophonic synth, there is only one voice to worry about, so this extra headroom is not necessary.
Some polyphonic synths were also designed to produce ‘thinner’ sounds, as to not completely muddy everything when multiple notes are played together.
If you don’t understand what this means, don’t worry. Poly synths still produce excellent sound quality, and I only wanted to include this one because it is indeed a distinction between the two types of synthesizers.
3. Mono Synths Excel At Bass, And Single Note Leads
If you’re looking to play primarily bass parts, this is an area mono synthesizers excel at.
Like a bass guitar, bass parts for synthesizers typically would only have you playing one note at a time anyway. The fat, strong sound of a mono synth lends itself well to bass, and the ability to glide between notes – a feature that’s common with mono synths, makes for really smooth transitions on bass parts.
They also make a great choice for solos, or other lead parts that would only need one note to be played at a time. Not only due to their sound, but to their note triggering system as well.
Because mono synths can only play a single note at a time, they have to prioritize certain notes over other notes if you hold down multiple keys at once. On most synths, the synthesizer will prioritize the last note that you played (other synths may allow you to prioritize the highest note or the lowest note being played instead.)
So, if you hold down one note, and then press down on another key, it will play that new key until you lift your finger back up again. Then, it will immediately start playing the other note.
This means that playing trills between two notes doesn’t require you to push down keys twice. You can simply press down and release a single key to alternate quickly between two notes.
Only having the ability to play a single note at one time forces you to focus strongly on each individual note that you’re about to play – not just the note itself, but the characteristics that make up the sound.
Remember, with only note at a time, you’ll often be able to use your free hand to shape the sound in real-time with changes to the filters, envelopes, and modulation.
Some people find this to be a huge advantage, especially when trying to improvise or come up with solos on the spot.
It can also be argued that this forces you to become a better player, as chords and complex poly parts can often mask mistakes.
Suggested Monophonic Synths Worth Considering:
The Advantages Of Polyphonic Synths
1. Multiple Notes
It’s pretty obvious how this can be beneficial.
Having the ability to play multiple notes at once opens up an entire world of additional possibilities, and allows you to add a synth part to any style or genre of music.
If you want to play complex jazz chords, or solo above a droning chord yourself, a polyphonic synthesizer is your only choice.
Note however that multiples notes does not mean unlimited notes. 4, 8, and 16 are common limitations on polyphonic synths.
Although you can truly do a lot with 4 notes at a time, this can still be quite a limitation at times – particularly if you come from a background of playing piano, where you had no such limits.
This is something to keep in mind when choosing which synthesizer to purchase.
If you’re a fan of pads or creating large soundscapes, this is something you’ll be able to do much more effectively on a polyphonic synth.
Pads are typically made up of long, droning chords that monophonic synths are simply not capable of.
3. Split The Keyboard
One neat feature built-in to many polyphonic synthesizers is the ability to define a point to split the keyboard. Then, play separate sounds at each part.
For example, you may wish to have one sound designed for the bass part on the lower keys, then a separate sound for the lead on the higher keys.
Although it’s possible to utilize different oscillators with different sounds on a monophonic synth, these are always layered on top of each other.
The ability to split the keyboard into two separate sections is a neat feature that is a lot of fun to use, especially for live playing.
4. Many Polyphonic Synthesizers Have A Mono Mode
Although not true of all of them, many polyphonic synthesizers have a mono mode built into them, that can be toggled on whenever you’d like.
Although it won’t help with the price of the instrument nor the sonic capabilities, this can aid you in bringing out the unique playing style that mono synths provide, as well as make it easier to do certain fast solos.
In a sense, you’re also getting a bit of the best of both worlds by purchasing a poly synth with a mono option.
Suggested Polyphonic Synths Worth Considering:
Which Should You Buy?
If you’re purchasing your first hardware synth and you’re trying to decide whether you should buy monophonic or polyphonic, I usually recommend poly synths to first-time buyers unless you have a specific reason not to.
If you’re only buying a synth to play bass parts, that may be an exception.
Ultimately, the added versatility that polyphonic synthesizers can provide make it a more satisfying option for most people, especially since many poly synths have a mono noise anyway.
While I would always encourage you to listen to many different synths within your budget and choose the one that inspires you the most, here are a few recommendations again for some quality polyphonic synthesizers:
After reading this article, I hope you have a better understanding on the differences between monophonic and polyphonic synthesizers, and the unique benefits and drawbacks that each provide.
It’s easy to believe that there are no reasons that anyone would want a monophonic synth anymore, but the truth is that there are serious use cases and there is still a high demand for monophonic analog synths. Having had the pleasure to play many of them myself, I can’t say I’m all that surprised.
I hope that you found this article helpful. If there are any questions I can answer for you, please feel free to let me know through the comment form below.
Thank you, and happy playing!