Sub bass you feel rather than hear — roughly 30 to 100 Hz, essentially mono, sitting close to a pure sine. Mid bass is the audible half: 100 to 500 Hz and above, home to all the character. Put the track on a club rig and the sub carries everything. Put it on a phone speaker and the sub is simply gone, leaving the mid bass as your entire low end.
Which is exactly why a track needs both. No sub and it comes across thin on big systems. No mids and the bassline evaporates on small ones.
What sub bass actually does
Weight is the sub’s one job: the chest-push you get standing in front of a rig. Human ears are bad at locating low frequencies, so any stereo information down there is thrown away. Actually it’s worse than thrown away: left-right phase differences can flat-out cancel your sub on a mono club system.
Hence the sub layer’s rules, which are dull by design:
- Mono, always.
- Simple waveform only: a sine, or a triangle with a touch of saturation.
- No unison, no detune, no chorus. Detune makes the sub’s level wobble in ways you can’t predict.
- One note at a time. Chords in the sub register just read as rumble.
Here’s a sub-heavy bass doing precisely that job.
What mid bass does
The personality lives in the mid bass: growl, pluck, honk, grit. This is the part that makes a bass recognizably yours. Its range runs from about 100 Hz up through 500 Hz and beyond, and unlike the sub it takes anything you throw at it: stereo, distortion, filtering, resonance, whatever serves the track.
Here’s the part that matters: small speakers only ever hear your mid bass. A typical phone driver reproduces almost nothing under 300 Hz. Leave that zone empty and the phone listener gets a hole where the bassline was supposed to be.
Nothing says the mid layer must come from a bass patch, either. Any sound with real midrange playing the same notes counts; a brass-style stack does the job fine.
The phone-speaker test
Bounce the loop, play it through your phone. Is the bassline melody still audible? Audible, not felt. If yes, the mid bass is pulling its weight. If the bassline just vanished, everything you built lives under 100 Hz with nothing above it.
Every track of mine goes through this check now. The number of “huge” basses that flunk it is embarrassing.
Two ways to build it: split or layer
Option 1: one patch, split processing
Run one bass patch and process its frequency bands separately. Everything under about 100 Hz stays clean and mono. Everything above gets the distortion, the stereo width, the movement. Do it with a multiband tool, or duplicate the channel and carve with complementary EQ. The win: it’s all one performance, so the layers can never drift apart.
Option 2: two separate layers
A dedicated sine sub carrying the notes, with a character patch stacked on top and highpassed around 100–120 Hz. You get more control, but also two parts to babysit: identical notes, identical glides, identical timing. A sub that slides while the mid doesn’t just sounds broken.
For ready-made mid-heavy patches worth studying, take our free Serum 2 bass house presets; the mid layer is what bass house lives or dies on, which makes them useful reference material.
Crossover points that work
No magic number exists, but these ranges stay out of trouble:
- 80–100 Hz split when the kick runs the low end and the bass is mostly there for character.
- 100–120 Hz split for the classic sub-plus-mid arrangement.
- Whatever you choose, everything under about 120 Hz stays mono.
A frequent mistake: chopping both layers at one frequency with steep slopes, which leaves a dip sitting right at the crossover. Softer slopes with a little overlap fix it; then confirm the sum on a spectrum analyzer. Two-layer basses that ship commercially arrive with this solved, and it’s on my checklist before any patch enters the whole Serum 2 catalog.
Common mistakes
- Unison on the sub layer. Detuned voices beat against each other and the level pumps at random. One voice for the sub, full stop.
- Stereo wideners under 100 Hz. Big on headphones, gone in mono.
- A mid layer on different notes from the sub. Octaves work; anything else is mud.
- Judging low end on headphones alone. Check it in mono, then check it on the phone.
Once your ear knows what to listen for, our Serum 2 preset bundles gather the bass-heavy packs at the lowest per-pack price, and most of those patches already keep sub and mid duties on separate desks.
Which packs fit which genre is ranked in best Serum 2 bass presets, and if the low end already feels crowded, the next read is why bass sounds muddy.
FAQ
Are sub bass and 808 the same thing?
An 808 is one specific flavor of sub bass — a mostly-sine tone with a pitched attack and a long decay. Every 808 is sub bass; plenty of sub bass isn’t an 808.
Where exactly does sub end and mid begin?
No official line exists. In practice I file everything under 100 Hz as sub territory and 100–500 Hz as mid bass. Where you set the crossover is a mixing decision, not a rule.
Do I always need two separate layers?
No. Split processing on a single patch often covers it, and staying in sync comes free. Reach for two layers when the top deserves a completely different character.
Why does my sub disappear in mono?
Phase. Detune or stereo effects on the sub create left-right differences, and summing to mono cancels them. Keep the sub mono at the source.
Build the sub for the club, build the mids for the phone, and one track survives both. Less a question of gear than of handing each frequency range exactly one job.
I run Monosounds.studio and make the packs myself. Ten-plus years of producing, 97+ releases, 16,000+ downloads. Every Serum 2 preset we ship passes a CPU check on a mid-range laptop and gets used in a real track before release. If it does not survive a mix, it does not go in the pack.
More about Maxim & the studio →
