How to make a Synth Bass for Synthwave

I. Introduction to synthwave bass [ 0:00 ]

Here we’ll be adding an important part of the rhythm section of our song. After the drums, we’re looking at how to make a synthwave bass in Logic Pro X. We’ll use Retro Synth and a free VST from Native Audio, Analog Dreams.
As a rhythmic and melodic instrument, the bass has a place of choice to set the vibe for your synthwave song.
We’ll go through how to set your synth, what ADSR envelopes are, and techniques to help with your bass tone, such as how to prevent sub-phase issues, basic layering techniques, and a few quick tips to enhance everything such as side-chain compression.

II. Creating a Bass Synth Patch with Retro Synth [ 0:27 ]

First create a MIDI track in Logic Pro X and select Retro Synth as the instrument.
It’s a basic and efficient native synthesizer that emulates different styles of retro-style synthesizers. We’ll keep it in the « Analog » mode on the top left corner.

1. How to set the oscillators :

1 - Keep Shape 1 and 2 oscillators on the saw wave.
2 - Set Shape 2 +12 semitones higher. You can also experiment with the "Cents" knob to create different tones.
3 - Click on the "Settings" tab on the bottom right and set the Stereo Spread to 0. Click again on the "Settings" tab to close the settings.
4 - Adjust the Mix or the volumes of both oscillators to test. In my example, I left it almost at 50%.

2. What is an ADSR envelope ?

An ADSR envelope is a fundamental component in synthesizers that helps shape the sound over time. The acronym stands for Attack, Decay, Sustain, and Release, which are the four stages the envelope goes through:

1 - Attack : This is the initial phase when a note is triggered. It determines how quickly the sound reaches its maximum level or amplitude after the note is played.
2 - Decay : After the attack phase, the sound begins to decrease in amplitude to a lower level, known as the sustain level. The decay parameter controls how quickly or slowly this decrease happens.
3 - Sustain : Once the decay phase reaches the sustain level, the sound remains at that level as long as the note is held down. Note that this parameter is a volume setting, as the other ones are a variations of volume over time.
4 - Release : When the note is released, the sound enters the release phase, during which it gradually fades out. The release parameter controls how quickly or slowly the sound fades away after the note is released.

It allows shaping the characteristics of a sound, such as its volume and duration, giving precise control over how it evolves from the moment it’s triggered to when it fades away.
It can be linked to the amplitude of the sound as well as to the filter of the synth to create interesting and dynamic shapes.

3. How to tweak the envelopes :

I’ll give you the way I set the filter and amp envelopes for my bass tone, but feel free to experiment !

Amp Envelope :
Attack : 0.64ms
Decay : 520ms
Sustain : 0.35
Release : 110ms

Filter Envelope :
Attack : 0ms
Decay : 170ms
Sustain : 0.04
Release : 270ms

Then apply the Filter envelope to the filter with the « Env » Knob in the filter area. The more you turn it, the more the filter envelope will affect the sound. I set it to +64%.

4. Add some effects

To make your sound more interesting, you can experiment with some effects.
In a classic 80s way, I added some chorus via the effects included in Retro Synth.
It’s a really simple effect section with two knobs: Mix and Rate.

1 - Mix: The ratio between the dry synth and the full effect. Here, I set it around 60%. Experiment with it.
2 - Rate: The speed of the effect. I usually like a slow chorus, but feel free to set it to your taste.

III. Preventing Sub-Bass Phase Issues [ 7:30 ]

Since we added some chorus and stereo spread to our patch, we have to take care of any potential sub-bass frequency issues.
These frequencies usually range from 20Hz to 60Hz. If they are out of phase, they can cancel each other out when combined into mono, resulting in a thin and weak sound, as well as causing balancing problems.
Here’s 2 free techniques in Logic Pro X that can help you with those issues :

1. Use a mid-side EQ :

1- Load a mid-side EQ on your bass track.
2 - On the "Side" tab of your EQ, apply a low-cut around 30Hz to 100Hz depending on your source.
3 - On the "Mid" tab of the EQ, apply a low-shelf to boost the bass frequencies if you feel like you’re losing some sub with the side cut you made.

2. Use the Direction Mixer plugin :

1 - Load the Direction Mixer plugin (Insert > Imaging) in stereo.
2 - Select the "LR" Input mode.
3 - Make sure the "Split" mode is ON.
4 - Select your crossover frequency, from 30Hz to 100Hz depending on your source.
5 - Set the "Spread Low" slider to 0.

You can apply those techniques to any track that has sub-bass information, or even to your mix bus to make sure the whole mix will translate well in the sub-bass frequencies.

IV. Basic Layering Techniques [ 10:42 ]

By layering multiple sounds together, you can create complex and textured sound. Each layer can contribute unique harmonic content and timbral characteristics, resulting in a bass sound that is rich and full-bodied. Think of it like an orchestra, where multiple instruments usually play the same part.

In my example, I use the free version of Analog Dreams from Native Instruments, which can be found here.
It’s a nice collection of 80s synth presets that will sound great for synthwave. It also has macro-knobs for quick sound settings if you’re not familiar with a full synth layout (oscillators, filters, envelopes, etc.).

The trick is to find another bass tone that complements the one we already have. For example:
The first one is bright and lacks depth? Find another that is simpler and more bass-oriented.
The first one has a nice body but lacks attack? Find a pluckier bass to add on top.

Here’s the step in Logic Pro X to group your instrument tracks together:
1 - Create a new software instrument track and load the VST you want into it.
2 - Select the new track and the first one.
3 - Group them in a summing track.
4 - Move the MIDI part from your first track to the summed group.
5 - Load a "Transpose" MIDI tool if the new instrument sounds too low or too high (or change the octave in your synth if that’s an option).
6 - Tweak your synth tone.
7 - Play with the volumes of your instrument tracks to find the right balance for your summed instrument.

V. Quick Tips for Enhancing Bass Sounds [ 14:44 ]

1. Compression :

It will help your bass or summed instruments sound more cohesive and consistent. In my example, I used a light compression setting since it’s still the composition process..

Here are the compressor settings I used on Logic’ Compressor :
Studio VCA tab
Ratio : 2:5
Attack : 30ms
Release : Auto
Threshold : tweak it to have around 2dB of compression.

2. Equalization :

A powerful tool to help enhance and start sculpting your synth tones.
No real fixed settings here, experiment with it :
Try boosting or reducing some bass with a Low-shelf, cutting some low-mids if your sound is too boxy or muddy, adding or cutting some top end if you need more or less definition.

3. Side-chain Compression :

This technique consists of triggering compression on one audio signal based on the amplitude of another signal, often used to create rhythmic pumping effects in electronic music. It can also be used for a less dramatic effect, especially during the mix stage to prevent the bass from overpowering the kick, for example. That’s what I’m going to explain step by step:

1 - Load a compressor on your bass track or group.
2 - Set the sidechain to your kick track.
3 - Set the ratio to 2:5, quick attack, and quick release.
3 - Set the threshold to aim for around 2-3dB of gain reduction.
4 - Aim for more if you want a more dramatic effect on your bass.

That way the kick always stays in front of everything, which is what we want for a dance type of song.

VI. Conclusion

Time to wrap it up, we created a basic bass synth tone using retro synth, learned what ADSR envelopes are, and how to start using layering techniques with a free VST! Finally, we learned a few quick techniques to enhance our bass sound.

As you embark on the composition journey for your song, remember to experiment with your own rhythms, tools, and ideas.

One thing I find funny about 80s bass sounds is that you can hear the same Yamaha DX 7 preset in a lot of classic pop songs from that decade, which just features maybe a chorus or an EQ to differentiate it from the original preset. So maybe try not to overthink it and find a super classic tone that works!

You can watch the whole video tutorial on this YouTube playlist or keep reading the next blog article to learn how to make a classic synthwave pad synth and create chords.

Hear the final result in my song « Rewind » here.
Find more about She Died in a Parking Lot here or on Youtube