smooth operator pro vs soothe 2

three plugins, one problem

resonance suppression became a category when Soothe 2 made it one. since then, a wave of tools has tried to answer the same question from different angles: how do you remove harshness from a signal without flattening what made it interesting?

Baby Audio’s Smooth Operator Pro ($129 regular) takes a node-based approach. oeksound’s Soothe 2 ($199) is the decade-refined reference, now with a successor (Soothe 3 at $259). and KERN SMOOTH at $29 is a third architectural choice: ERB-domain psychoacoustic bands, native M/S routing, no iLok.

full disclosure: i make SMOOTH. this comparison is honest because it has to be. you can try SMOOTH for free and A/B it yourself.

what smooth operator pro actually does

Baby Audio’s angle is visual and surgical. Smooth Operator Pro presents detected resonances as nodes on a frequency graph. each node shows you where the problem is and how hard the suppressor is working. you can click any node and apply a custom EQ curve at that specific frequency, on top of the automatic suppression.

that per-node EQ override is the headline feature that neither Soothe 2 nor SMOOTH offers. on a difficult acoustic guitar where the body resonance at 280 Hz needs a different treatment than the fret squeak at 4 kHz, per-node control lets you handle them independently without touching global depth or selectivity.

Smooth Operator Pro also ships 184 presets covering a wide range of sources, includes M/S processing, and offers a delta monitoring mode (hear only what the plugin is removing). no iLok: Plugin Alliance activation, which has been iLok-free since 2011.

the gap between Smooth Operator (the original) and Smooth Operator Pro is significant. the original lacks per-node EQ, M/S, and the sidechain. if you are comparing “smooth operator vs soothe 2,” make sure you are looking at the Pro version.

what soothe 2 does

Soothe 2 has been the reference resonance suppressor for the better part of a decade. it works across the full spectrum with adjustable depth, selectivity, and a soft/hard mode toggle. the analysis engine is refined because it has been through years of commercial use, edge cases, and incremental updates.

the key workflow features that made it the standard: external sidechain for spectral unmasking between tracks, a well-curated preset library built up over years, and a soft/hard mode split that gives you either a safe transparent treatment or a more aggressive de-resonance grab.

what Soothe 2 does not have at this point: a true low-latency mode (that arrived in Soothe 3), and a price that makes sense relative to its successor. with a $55 upgrade to Soothe 3 ($259 new), the case for buying Soothe 2 new is narrow. if you already own it, it still works and the license is permanent. if you are shopping today, the $55 Soothe 3 upgrade path changes the math considerably.

(there is a longer comparison of Soothe 3 and SMOOTH separately in this guide series if that decision is what you need.)

what SMOOTH does differently

KERN SMOOTH is not trying to win on features. it is trying to win on the question: does the suppression land where your ears notice it?

the engine works across 40 ERB-spaced bands. ERB (equivalent rectangular bandwidth) is the psychoacoustic scale that models how your cochlea actually resolves frequency. bands are narrow in the 200 Hz to 5 kHz range where ears are most sensitive, and wider in the sub-bass and high air where they are not. a 3 dB resonance at 3.2 kHz triggers heavy suppression because that is exactly where your ears notice it. a 3 dB bump at 80 Hz triggers proportionally less. the processing concentrates where the problem is perceptually, not where it appears on a linear frequency axis.

M/S routing is native: SMOOTH can process mid and side channels independently, which means a centred sibilance resonance can be suppressed without touching the stereo reverb tail sitting in the sides. Smooth Operator Pro also offers M/S. Soothe 2 does not.

what SMOOTH does not have: per-node EQ override (Smooth Operator Pro’s core differentiator), external sidechain, or a preset library measured in the hundreds.

what SMOOTH does have: no iLok, an offline-forever license, under 3% CPU on macOS at 44.1 kHz per instance, and a $29 price tag that is $100 less than Smooth Operator Pro and well below Soothe 2.

the comparison table

where each one wins

smooth operator pro wins when

you want to see and control individual resonances rather than set global depth and selectivity. the node-based interface is genuinely different from anything Soothe 2 or SMOOTH offer. if you mix acoustic instruments where specific low-mid resonances need different treatment than high-frequency ones, the per-node EQ override is not a gimmick. it changes what you can do in a single plugin.

184 presets also means more starting points across a wider variety of sources. if you reach for presets first and dial from there, Smooth Operator Pro has more material to start from.

soothe 2 wins when

you need external sidechain spectral ducking on a regular basis, or you are buying into a catalogue where the $55 Soothe 3 upgrade path makes the entry cost make sense. standalone, in 2026, Soothe 2 is a harder sell than it was two years ago.

if you own it already, it is still a strong plugin and the license is permanent.

SMOOTH wins when

the decision comes down to price and architecture. $29 versus $129 for Smooth Operator Pro is a real gap, especially if resonance work is not the core of your session workflow. the ERB-domain engine concentrates suppression perceptually. M/S routing is there if you need it. and the no-iLok, offline-forever licensing removes a category of friction that the other two either have or partially share.

for producers who run Ableton Live on a laptop at 44.1 kHz and want a resonance suppressor that does not require an account, a dongle, or a $100+ commitment, SMOOTH is the cleanest answer.

the soothe 2 question

a note on where Soothe 2 sits in 2026: its successor, Soothe 3 ($259, with a $55 upgrade from Soothe 2), ships a true low-latency tracking mode, a redesigned dual-mode engine, and multichannel support up to 9.1.6. if you are comparing Smooth Operator Pro against Soothe 2 specifically, the question is whether you are comparing against the right version of the oeksound product. see the full Soothe 3 upgrade guide in this series for the longer version of that decision.

frequently asked questions

frequently asked questions

is Baby Audio Smooth Operator Pro the same as Smooth Operator?

no. Smooth Operator (the original, still available) is the basic version. Smooth Operator Pro adds per-node EQ override, M/S processing, an external sidechain, and a delta monitoring mode. the Pro version is what competes directly with Soothe 2. at $129 regular, it sits between the free/cheap tier and the Soothe 2 price point.

does Baby Audio Smooth Operator Pro require iLok?

no. Smooth Operator Pro is distributed through Plugin Alliance, which stopped using iLok in 2011. it activates through Plugin Alliance software, with no physical dongle and no iLok account required.

what does Smooth Operator Pro do that Soothe 2 does not?

per-node EQ override is the headline difference. you can click any detected resonance node in the interface and apply a custom EQ curve at that specific frequency, on top of the suppression. Soothe 2 applies suppression uniformly based on depth and selectivity. Smooth Operator Pro gives you per-node sculpting as a second layer. it also ships with 184 presets across a wide range of sources.

what does Soothe 2 do that Smooth Operator Pro does not?

Soothe 2 uses a spectral analysis engine that has been battle-tested across a decade of commercial sessions. its external sidechain is widely used for spectral unmasking between tracks. the preset library is smaller but heavily curated. and Soothe 3 (the successor) is now available at $259 with a $55 upgrade, so Soothe 2 on its own is increasingly less competitive on its own terms.

where does KERN SMOOTH fit in this comparison?

KERN SMOOTH at $29 uses a different engine architecture than both: 40 ERB bands mapped to human hearing, native M/S routing, no iLok, offline-forever license. the trade-off is that it lacks the per-node EQ override of Smooth Operator Pro and the decade-refined analysis engine of Soothe 2. for straightforward resonance work on vocals, synths, and acoustic instruments, it competes on sound. for advanced per-node control or sidechain spectral ducking, Smooth Operator Pro or Soothe 2 are the better picks.

a note from the developer

i built SMOOTH because the plugins i kept recommending to producers cost more than they should and required more account management than they needed to. Soothe 2 was the gold standard for years, and Smooth Operator Pro is a genuinely clever answer from a different angle. neither was the product i wanted to own at $29 with no account overhead.

SMOOTH is a third architectural option, not a clone. if your workflow demands per-node EQ control or external sidechain spectral unmasking, Smooth Operator Pro is the better tool. if you run Soothe 2 on every track of every session and the $55 Soothe 3 upgrade unlocks low-latency tracking, that math works too.

the use case where SMOOTH wins outright is simpler and more common than either of those: a vocal bus or synth track with a harshness problem, a producer who wants to remove it without spending $129 on the tool or 20 minutes learning a new interface. that is most resonance work. for that, $29 and five knobs is enough.

jonas@kernaudio.io: if your ears tell you something different from what i wrote here, i want to know.