Airy, Headroomer and FireMaximizer: 3 Free Plugins to Grab
Three Plugins, Zero Overlap
This week's free-plugin pickup doesn't have a theme so much as it has a gap it fills. Instead of another synth or another saturator, you're getting a stereo widener that won't touch your bass, a channel cleanup tool built for the production stage, and a mastering-grade loudness plugin that's normally $137 — free for a limited window. Different jobs, same signal chain, and all three are worth an install today.
Airy — A Stereo Widener That Actually Leaves Your Bass Alone
HARMONICO dsp's Airy is a free perceptual stereo widener, and the pitch is specific: it measures inter-channel coherence per frequency band and adds only the width that's actually missing, rather than smearing a fixed amount of delay or phase trickery across everything that hits it. The company describes it as "born from the Airy diffraction pattern," which is more marketing flourish than something you need to understand to use the plugin — what matters is how it behaves on a mix.
The mono-safety claim is the real selling point for anyone working low end. Airy processes the Side channel only, so the mono sum of your signal is preserved by construction — you can push the width control hard, hit the MONO button, and fold everything back to center with no artifacts. For a bass-focused producer that's already useful, but the control that matters most here is MONO BELOW, which applies elliptical bass-mono filtering so anything under your chosen frequency stays locked to the center while the highs and mids widen freely. That's the exact problem stock widener plugins create when you throw them across a full mix — sub and low-bass energy going stereo and losing punch or translating badly to club systems and phone speakers. Airy lets you widen a pad, a synth layer, or an overhead bus without touching the low end doing the actual work in your track.
Beyond MONO BELOW, Airy ships with a stereo field map you paint width onto directly, a DIFFUSION control that shifts between a focused and a more diffuse "airy" character, a CORR POS control that bounds correlation for vinyl or broadcast-safety reasons, RIDE (width that follows the signal's dynamics or an external sidechain), two tempo-syncable LFOs, and a GENERATE mode for synthesizing stereo width from a mono source entirely. It runs at zero latency, needs no activation or account, and is available now as VST3/AU/AAX for Windows 10/11 and macOS 10.15+ (Intel and Apple Silicon).
Practical Ableton use case: drop Airy on a return track for pads, synth layers, or a drum overhead bus, dial MONO BELOW to somewhere around 120–150 Hz depending on the track, and widen aggressively above that line. Your kick and bass stay centered and full-power in mono playback; everything else gets the space.
Headroomer — Cleanup Before You Even Start Mixing
NoirSonance's Headroomer solves a much less glamorous problem: the low rumble and high-frequency hiss sitting in tracks before you've done anything to them. It's a CPU-light channel plugin built around two controls — a low cut and a high cut, both using gentle filter slopes rather than steep, obvious-sounding cuts — meant to be dropped on individual tracks, groups, returns, or buses during the production and arrangement stage, not as a mixing decision.
The point of a tool like this is that it's boring on purpose. You're not sculpting tone with it; you're removing the stuff below and above your useful range so that every plugin that touches the signal afterward — compressors, saturators, EQs — is working with a cleaner starting point instead of also having to deal with sub-20Hz rumble or hiss riding along for the whole session. Because it's CPU-light, NoirSonance's pitch is that you can put an instance on every channel in a large session without it becoming a resource problem, which is the actual barrier that stops most producers from doing this kind of cleanup consistently.
Headroomer is free, structured as pay-what-you-want with suggested donation tiers (€5/€10/€15/€20) but a genuine €0 option, and it's available as VST for Windows and AU for macOS.
Practical Ableton use case: insert Headroomer as the first device on every audio track during tracking or arrangement — before EQ Eight, before Saturator, before anything else — so your low end and high end start clean. It's especially useful on recorded bass DI or amp takes, where rumble below the fundamental is common and easy to miss until it's stacked under six other tracks.
FireMaximizer — Normally $137, Free Through October 18
This one's different from the other two: it's not permanently free, it's a time-limited promotion, and it's worth being precise about that so you don't go looking for it in November and find a $137 plugin instead.
UnitedPlugins' FireMaximizer (developed by Firesonic) is a mastering-grade loudness processor that blends four algorithms — clipper, saturator, limiter, and multiband limiter — through an XY pad interface, so instead of choosing one loudness tool you're dialing in a mix of all four to land on a specific character. It runs 64-bit internal processing with up to 16x oversampling and handles sample rates up to 192kHz and beyond. Licensing is file-based (no iLok, no dongle, no internet check required at runtime), and it supports multi-computer use for a single license holder.
Per Bedroom Producers Blog's coverage, UnitedPlugins is offering FireMaximizer completely free through October 18, 2026: add it to your cart on unitedplugins.com, create a free account if you don't have one, and apply the coupon code SiyuFMX100 at checkout to bring the price to zero. After the promo ends, it reverts to its regular $137 price (there's also a standard 15-day unlimited free trial available any time, which is separate from this promo and doesn't expire your access the same way).
Practical Ableton use case: put FireMaximizer on your master bus during final loudness passes and use the XY pad to blend transparent limiting against something with more clipper/saturator character, rather than reaching for a single-algorithm limiter and hoping the character matches the track. It's a reasonable free alternative to test against whatever you're currently using before this window closes.
Suggested Signal Order
If you're grabbing all three, a sensible chain on a bass-heavy Ableton session looks like: Headroomer first on individual tracks and buses to clean up rumble and hiss before anything else touches the signal, Airy on return tracks or wide-elements buses (not the low end itself) to add width without smearing your mono bass, and FireMaximizer last, on the master bus, for final loudness shaping once everything else is sitting where you want it.
LEC's Own Free Tools
If you haven't grabbed them yet, LEC also has two permanently free plugins worth adding to this same pickup: Ratchet, a free plugin, and The Clap, a free plugin. Both are free, no email gate, no expiration.
The Takeaway
None of these three plugins are trying to do the same job, which is exactly why they're worth grabbing together instead of one at a time. Airy fixes a specific, common mistake (widening that ruins your low end) rather than just being "another widener." Headroomer is unglamorous but solves a real workflow gap most producers never automate. And FireMaximizer is a genuinely capable mastering tool at zero cost for the next few weeks — there's no real reason not to test it against your current go-to before the October 18 deadline closes the door.