Synthwave Bass Sound Design

Let’s talk about synthwave bass. If you’ve ever wondered why some synthwave tracks feel like a midnight drive down a neon-lit highway while others just sit there, the answer is usually the bass. A great synthwave bass isn’t just something to fill the low end. It’s the engine underneath everything. Get it right, and your wide pads suddenly sound cinematic, your drums hit bigger, and even a simple four-chord progression starts to move.

As we go, keep in mind that good synthwave bass sound design means balancing three things that love to fight each other: the round analog-style warmth that makes it feel ’80s, enough controlled aggression to push the track forward without getting harsh, and a low end that holds up on earbuds and car speakers just as well as it does in your studio.

And relax, you don’t need a room full of vintage hardware to pull this off. Serum has everything you need to build a retro synth bass that feels genuinely nostalgic, not like another generic preset pulled from an ’80s playlist. In this synthwave bass tutorial, we’ll build three essential sounds step by step: the classic resonant filter-sweep bass with that squelchy, expressive character at the heart of the genre, the driving running bass that powers outrun and darksynth with its 16th-note pulse, and the dark, detuned Reese bass for the wide, moody, heavier moments. For each one, I’ll also show you when it belongs in your track, because choosing the right bass for the moment matters just as much as designing it.

So open up Serum, load a fresh init patch, and let’s get started.

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• The Midnight "Los Angeles" Breakdown: Synths in Serum
• Timecop1983 "On The Run" Serum Tutorial & Breakdown
• Kavinsky "Odd Look" Serum Tutorial & Breakdown

Which Synthwave Bass Should You Use?

Before we even open Serum, let’s take a step back and ask one simple question: what does the bass need to do in this arrangement? That answer decides the patch. One of the most common reasons a synthwave track loses its focus is trying to make a single bass sound do every job at once, so think of it this way: arrangement first, sound design second.

If your bass is carrying a melody or the hook, reach for the resonant filter-sweep bass. It’s round and almost vocal, and it leaves plenty of room for those chorus-soaked guitars and lush pads to shine. If your bass is the groove, go with the running bass. In a driving outrun track it works almost like a second kick drum, firing off short, repeatable notes that lock everything into place. And if your bass is the threat, the dark presence lurking under a cyberpunk or darksynth track, the Reese bass is your tool, wide, moving and distorted, like it’s always just about to break.

Just remember, these are starting points, not rules. Plenty of great synthwave tracks ride a running bass through the verse and then switch to a Reese when the drop hits, so feel free to mix and match once you know what each one does best.

1. How Do You Make a Resonant Filter-Sweep Synthwave Bass?

This 4-bar loop sits in D minor and keeps the notes simple so your filter can do the talking. You start on F1, step up to G1, then drop to D1 and hold it for three beats, and those dotted notes land a little ahead of the beat so the bass pushes the track forward while the long D1 gives your filter envelope time to sweep open. At the end of bar 2, A#1, A1 and G1 overlap a bit on purpose, so with Serum in Mono and Legato the fill glides like someone singing it. Bars 3 and 4 repeat the F1 to G1 move, then jump up to C2 to lift the energy, and the last fill walks you back down to F1 without overlapping, so those notes retrigger with more punch. Put together, you get long sweeping notes, little melodic hooks and smooth glide, which is that classic ’80s synthwave feel, and if the D1 disappears on small speakers, add a touch of resonance to keep it audible on earbuds.

Serum settings

Let’s open up the patch and see how it all fits together. You’ve got three sound sources stacked here. Osc A plays a plain saw with 5 unison voices, tuned down 10 cents. Osc B sits one octave lower on the “Jno” wavetable with 4 unison voices, tuned up 10 cents, so the two oscillators drift against each other and give you that warm analog wobble. Under them, the Sub oscillator runs a saw at -1 octave to hold down the low end.

All three run into the MG Low 12, a 12 dB Moog-style low-pass filter. The 12 dB slope sounds softer and rounder than a 24 dB filter, which suits the vintage vibe, and you keep the resonance up enough to hear that little peak as the filter moves.

Env 1 drives the whole sweep. Besides controlling volume, it modulates six things at once: filter cutoff, filter resonance, unison detune on both oscillators, the Sync warp on Osc B and the wet amount on the flanger. With a 5 ms attack, a 2.5 second decay and sustain down at -29 dB, every note hits bright, wide and buzzy, then closes down and narrows as it fades. That’s why the long D1 and C2 notes in the MIDI sound so alive: you hear the whole sweep play out.

Down in Voicing, you set Mono and Legato so only one note plays at a time and overlapping notes don’t restart the envelope. A short Portamento time gives you the slide between notes, and the pitch bend range sits at 2 semitones for small expressive bends if you want them.

FX Section

Over in the FX tab you’ve got four effects working in order, so let’s walk through them. Tube distortion comes first with low drive and a high mix, which warms the bass up and adds harmonics that help it come through on small speakers. Hyper and Dimension sit next with low mix settings, thickening the top end and adding a bit of stereo width without blurring the low end, so your bass still holds up in mono. The Flanger gives you the movement: Env 1 pushes its mix up on every note, so each hit opens with a jet-like shimmer that fades as the filter closes. The Compressor finishes the chain and evens out the bright start and darker tail of each note, keeping the bass steady under your drums, and if you bypass each effect one at a time you’ll hear what every piece adds.

When to use it

Typically mid-tempo, emotional synthwave and dreamwave around 85 to 120 BPM, where the bass can carry a countermelody under the vocal or lead. It works especially well in verses and choruses of The Midnight or Timecop1983-style tracks. For more cinematic songs, automate the cutoff across sections: a darker verse bass builds tension, then opens in the chorus when the drums and lead arrive.

2. How Do You Make a Running Bass in Serum?

Steady eighth notes in B♭ minor drive this one from start to finish, and that constant pulse works like a second kick drum driving the track. The roots move from A#1 to F#1 to G#1, the i to VI to VII progression you’ll hear all over outrun, so you feel the chords change under your pads without the bass doing anything fancy. The fun sits at the ends of the bars: an F1 slides you into F#1, a C#1, D#1, F#1 walk lifts you into G#1, and a quick 16th-note fill up high (D#2, C#2, C2) brings you back to the top of the loop. Every note touches the next without overlapping, so each one retriggers the envelope with a clean, punchy attack, and if you want them tighter, use a fast decay on the amp envelope instead of chopping the MIDI. 

Serum settings

Let’s open this one up. You’ve got two oscillators doing the work here, with the Sub and Noise switched off. Osc A plays the MB Saw with 6 unison voices and a touch of Sync warp for some extra bite, and Osc B runs the “Jno” wavetable with 7 unison voices. You set both one octave down, so the bass sits low and thick while the unison stacks give it that wide, buzzy ’80s texture.

Both oscillators feed the MG Low 24, a 24 dB Moog-style low-pass. This one cuts harder than the 12 dB filter from the sweep bass, which keeps the running notes tight and stops the top end from getting fizzy when you repeat them fast. Key tracking is on too, so higher notes in the fills open the filter a little more and stay clear.

Env 1 handles the punch. With a 5 ms attack, a 606 ms decay and sustain at -11.5 dB, every eighth note hits bright and settles down quickly, and since Env 1 also drives the filter cutoff, each note gets its own little pluck. That’s where the shorter, tighter feel comes from.

Then you’ve got three LFOs adding life. LFO 1 runs a slow 2-bar triangle on the fine tuning of both oscillators, so the pitch drifts a hair like an old tape machine or a warm analog synth. LFO 2 is the fun one: it’s synced to quarter notes and controls the volume, ducking the start of every beat and swelling back up. That gives you a built-in sidechain pump that locks to your kick without any routing. LFO 3 moves over 2 bars and sweeps the filter cutoff, resonance, Osc B’s detune and the phaser, so the tone opens and closes slowly across the phrase while the notes keep running.

FX Section

In the FX tab you’ve got four effects working in order, starting with Hyper/Dimension, where 7 unison voices and a low Dimension mix widen the stack of eighth notes before anything else touches them. Tube distortion comes next with its PRE filter set around 1.7 kHz, so the grit lands on the upper mids and your low end stays clean and solid. The Compressor follows with a fast attack and a high mix, flattening any notes that jump out so the line feels like one machine-tight pulse under your drums. The Phaser closes the chain, and since LFO 3 sweeps its depth and frequency over 2 bars along with your filter, the swirl rises and falls with the tone, so bypass each effect one at a time and you’ll hear what every piece adds to the groove.

When to use it

Typically driving outrun and synthwave at around 100 to 120 BPM, plus faster darksynth. It's the go-to for "night drive" energy in the style of Kavinsky, Miami Nights 1984 or Dance With The Dead. Use it in choruses, drops and main loops, and drop it out in breakdowns so its return hits harder. Because it moves constantly, keep the lead and arps simpler on top of it.

3. How Do You Make a Reese Bass for Synthwave?

Long, heavy notes in G# minor carry this one and moves from G#1 to F#1 to B1, a moody i to VII to III progression that fits darksynth and cyberpunk tracks. You let the notes ring long, up to three full beats on the B1 in bar 4, because a Reese gets its growl from detuned voices drifting in and out of phase, and you only hear that wobble when the notes sustain. Between those long notes, quick jumps up to F#2, G#2 and a little C#2, D#2, C#2 turn give the line a lead-like edge so the low end doesn’t turn into one long rumble. At the end of bar 3, G#2 is still held when C#2 comes in, and with Mono and Legato on that overlap makes Serum glide down instead of retriggering, so you get a heavy, smeared slide right before the bar change into B1.

Serum settings

Let’s open this one up. A Reese comes from a simple trick: two saw waves tuned a little apart so they rub against each other and create that slow, growling phase movement. You set it up here with Osc A on the Basic_Mdc saw tuned down 5 cents and Osc B on a Basic Shapes saw tuned up 10 cents, both one octave down. That 15-cent gap makes the waves drift in and out of phase, and that drift is the wobble you hear when the long notes sustain.

Then you stack unison on top, 5 voices on Osc A and 6 on Osc B with moderate detune, which turns the wobble into a thick, wide wall. Down low, the Sub oscillator runs at -1 octave with its level kept low, giving you a solid foundation so the detuned saws don’t make the low end feel unstable.

Everything runs into the MG Low 24, the same 24 dB Moog-style low-pass from the running bass. You keep the cutoff around the middle with low resonance, so the Reese stays dark and heavy and the fizzy top end of all those saws gets tamed.

You’ve got two envelopes shaping it. Env 1 controls the main volume and the filter cutoff with a quick 5.6 ms attack and sustain almost at full level, so the notes hold steady and let the phasing play out. Env 2 adds a second layer: a 20 ms attack, a 906 ms decay and sustain at 78%, routed to the volume of both oscillators and the filter cutoff. Each note opens a bit brighter and louder, then settles down a little as it holds, so you get a subtle bloom at the start of every hit.

In Voicing, you’ve got Mono and Legato on with a short Porta time, which gives you that smeared slide on the overlapping G#2 to C#2 move in bar 3.

FX Section

In the FX tab you’ve got four effects working in order, starting with Hyper/Dimension at low mix settings, which add a touch more thickness and stereo spread on top of the unison you already have in the oscillators. Tube distortion comes next with low drive and a 50% mix, warming up the detuned saws and adding grit to the growl without flattening the phase movement. The Plate reverb sets this bass apart from the other two, with a small size, wide stereo and a low cut that keeps the sub tight while the tail wraps the higher notes in a dark, cinematic space. The Phaser closes the chain with a slow rate and plenty of feedback, adding a sweeping swirl on top of the natural phasing, so bypass the reverb and phaser one at a time and you’ll hear how much of the moody feel comes from them.

When to use it

Typically darksynth, cyberpunk and heavier synthwave, from slow, menacing 80 BPM grooves to aggressive 110 to 130 BPM tracks in the style of Carpenter Brut or Perturbator. It shines in drops, breakdowns, intros that need dread, and film-style tension cues. It's usually too heavy for bright, nostalgic synthwave unless you filter it way down.

FAQ

What is the best Serum filter for a synthwave bass?

It depends on which bass you’re making. For the resonant sweep bass, use a 12 dB Moog-style low-pass like MG Low 12. Its gentler slope sounds round and vintage, and it lets you hear the resonance peak as Env 1 sweeps the cutoff. For running basses and Reese basses, switch to a 24 dB low-pass like MG Low 24. The steeper slope cuts more of the top end, which keeps fast eighth notes tight and tames the fizz from stacked, detuned saws. Whichever filter you choose, set its cutoff by ear against your kick and pads. If the bass hides your chords, bring the cutoff down. If it sounds dull on small speakers, add a little resonance or drive to bring back some harmonics.

What is a running bass in synthwave?

A running bass plays steady eighth or sixteenth notes almost nonstop, so it drives the track like a second kick drum. You hear it all over outrun because it gives you that feeling of speeding down a highway at night. Usually it sits on the root of each chord and repeats it, then adds short fills or walk-ups at the end of a bar to lead into the next chord. Short, plucky notes help, so use a fast amp envelope and a 24 dB filter to keep each hit tight. Keep the velocities even, the way an ’80s sequencer would play them. Then sync a volume LFO to quarter notes so the bass pumps along with your kick.

Can you use a Reese bass in synthwave?

Yes, and it works best in darksynth and the darker, cyberpunk side of synthwave. A Reese is two slightly detuned saws drifting in and out of phase, which gives you a slow, growling wobble that sounds tense. Hold the notes long so the phasing has time to move, and keep a clean mono sub under it so your low end stays solid on club systems and in mono. Filter off the top so it doesn’t fight your pads and leads. In brighter, nostalgic tracks, save the Reese for a breakdown or drop where you want the mood to turn dark.

What BPM is synthwave?

It covers a wide range. Dreamy, emotional synthwave usually sits around 85 to 120 BPM. Outrun tends to land between 100 and 120 BPM, and darksynth often goes faster, sometimes over 130. Let the bass follow the energy more than the tempo. The resonant sweep bass suits slower, emotional tracks where long notes have time to bloom. The running bass fits driving tracks at mid to fast tempos. The Reese works anywhere you want tension, from slow, heavy grooves to fast darksynth.

When you build your next patch, focus on the feeling before the plugin chain: steady propulsion, late-night tension, or warm nostalgia. Get that character right with the oscillator choice, envelope and MIDI rhythm first. The rest is just polish, and that's where a good bass becomes the part listeners remember after the neon fades.

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