A good bell preset often separates a sketch from a record. It’s the bell that makes a trap melody feel expensive, gives a house breakdown its emotion, and puts the finishing gloss on a pop hook. And unlike most patch types, you can’t cheat your way there with a saw wave.
This guide pulls apart how bells work in Xfer Serum 2 — the inharmonic content, the FM ratios, the envelope shapes, the reverb moves behind that ringing tail — and there are 15 free presets included, so your starting point is professional patches rather than an init screen.
First thing to get your head around: what defines a bell is partials sitting at non-whole-number multiples of the root. That single fact is the entire sound.
Start with the free pack
Grab the Free Serum 2 Bell Presets: 15 Bell presets, audio demo for each, all royalty-free. Installing takes less than a minute: unzip into the Serum 2 user preset folder, hit rescan.
Inside you’ll find glassy soft bells aimed at pop and future bass, harder metallic ones for trap and drill, a handful of tuned-percussion patches living somewhere between bell and mallet, and two long shimmering ones made for breakdowns. The macros control brightness, decay and reverb amount.
Who’s it for? Anyone stuck recycling the same stock FM bell who wants patches that genuinely differ from one another.
The sound, part by part
Where the metal comes from
There are two paths. Path one is FM: make oscillator B modulate oscillator A at a non-integer ratio (try around 1.4:1, 2.7:1 or 3.5:1) and the resulting sidebands land inharmonically. Tiny nudges to that ratio transform the character entirely, so adjust it in very small steps.
Path two is picking the right wavetable. A table with sharp, unevenly spaced spectral peaks delivers bell content with no FM involved. Serum 2’s spectral oscillator shines here since it lets you sculpt those peaks directly. For what each engine does best, see the oscillator guide.
The envelope
Attack instant, decay somewhere between 400 ms and 2 seconds, sustain at zero. Since real bells decay exponentially, a longer decay with its curve bent toward the start reads far more natural than a linear drop.
Now the money move: send an envelope to FM amount and give it a faster decay than the amp envelope, so the metallic partials fade out before the fundamental. Real bells ring purer as they die away for exactly this reason, and it’s what separates a bell from a buzz.
Brightness and keytracking
Down in the low octaves, bells go dull quickly. Enable filter keytracking and also route note pitch into FM amount, keeping high notes shiny while stopping low notes from collapsing into a growl.
Roll off with a low-pass around 12–14 kHz to remove the digital edge. Bells are among the rare patches where trimming a bit of top end makes them sound more expensive rather than less.
The FX chain
Start with ping-pong delay: 1/8 dotted, feedback at 30–40%, wet at 20–30%, return high-passed at 500 Hz. Follow with a long plate or shimmer reverb in the 2 to 4 second range, high-passed as well.
Chorus goes last, and gently. Slather heavy chorus on an inharmonic sound and it reads as out of tune, not wide. Ordering and the send-versus-insert debate are handled in the effects guide.
Tempo, groove and arrangement
Bells fit any tempo; the decay just has to change. Half-time trap around 140 written wants 600 ms to 1 second so each note bleeds into the next. House at 124 wants 300–600 ms, keeping the pattern readable.
Write sparse bell melodies. Three or four notes a bar, with a dotted delay filling the space between, will always sound like more than eight notes do.
Here’s an arrangement habit worth stealing: put the bell melody one octave above where instinct says. Bells nearly always belong at the top of the arrangement anyway, and shifting them up clears the mids for vocals and chords. The lo-fi tutorial applies this same placement thinking to keys.
Mixing notes for bells
High-pass at 300–400 Hz. There’s zero useful low end in a bell, and once it’s gone you can run the level way hotter than you’d guess.
Dry narrow, wet wide. That contrast is what the ear reads as sparkle; widening the dry bell itself just smears it.
Keep an eye on 3–5 kHz. Stack two bell patches and the inharmonic partials pile up there until it hurts. A wide 2 dB dip on one of them solves it.
If the bell is bright and the track has busy hats, de-ess or dynamic-EQ the top. A fast dynamic cut at 8 kHz keyed to the bell stops it stabbing through.
And sidechain the reverb return rather than the bell itself — the tail ducks under the kick, the attack survives.
Common mistakes
Integer FM ratios. 2:1 produces a harmonic sound: bright, sure, but not a bell. Get off the whole numbers.
Sustain above zero. If it holds while the key is down, you’ve made an organ. Zero the sustain and let the decay carry everything.
Playing too low. Under roughly C3 the inharmonic partials bunch together and read as an error, not a texture.
Reaching for reverb to fake size. Long delays paired with a modest reverb sound bigger than a giant reverb ever does, and they stay locked to the track’s tempo.
When you outgrow the freebies
These 15 patches came out of the same design sessions as our Serum 2 preset bundles, full genre collections priced at a fraction of buying packs individually. After something more genre-specific? Every Serum 2 pack I’ve made is gathered in one place.
FAQ
Do these presets work in Serum 1?
No, they’re built on the Serum 2 engine. The good news: Serum 2 is a free update for anyone who owns Serum 1.
What makes a synth sound like a bell?
Inharmonic partials (frequencies that aren’t whole-number multiples of the root) combined with a fast attack and a long, sustain-free decay. The quickest route there is FM at a non-integer ratio.
My bell sounds like a buzzy growl instead of a bell. What is wrong?
Your FM amount is fixed and cranked too high. Assign an envelope to FM amount with a quick decay so the metallic content clears out early, then halve the overall FM depth.
Are they really royalty-free?
Yes. Use them in releases, client projects, beats you sell, no credit needed.
Can I use them in any DAW?
Anywhere Serum 2 runs: Ableton, FL Studio, Logic, Cubase, Studio One, you name it.
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.
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