Flagship product
HRF — Harmonic Reinforcement Filter
A filter that reads musical pitch, not just frequency. It optimally supports the harmonics that belong and tames the ones that do not — gluing sounds together, whilst easing masking and uneven dynamic balance, so your mix keeps its movement and can breathe.
How it works
Shape the harmonic balance
HRF listens to incoming audio and analyses its tonal structure across the 12 chromatic pitches. Rather than treating a mix only as conventional frequency bands, it looks at how harmonic content is distributed across the spectrum and uses that information to guide a bank of tonal filters.
The Optimizer turns the analysis into practical processing automatically, reducing less-prominent tonal content relative to the strongest harmonic components to help bring greater focus, separation and cohesion to complex audio. Because HRF works on the combined signal, it can reshape harmonic balance without needing access to the individual tracks. Every tonal filter remains available for manual adjustment when you want to refine the result.
HRF also makes the process visible. The Harmonic Signature provides a clear 12-tone before-and-after comparison, the rotating 3D visualisations offer a spatial representation of the analysed harmonic structure, and the Spectrum view connects that tonal information back to detailed frequency content.
Direct and Complement output filtering, Dry/Wet blending and Makeup Gain let you choose where HRF acts and how strongly it becomes part of the final sound.
The result is a more open, coherent and naturally balanced sound. By discovering the true harmonic structure of your audio, HRF optimally balances both the relationships between different sounds and the harmonic balance within each individual sound—gluing related content together, reducing masking so each element has its own harmonic space, and redistributing energy across the dynamic range so everything has room to move and its own unique dynamic space. This is what we mean when we say HRF lets your sound breathe.
Inside the interface
What you see, and what it means
HRF listens continuously and builds a harmonic signature of the material: how much of each chromatic tone it has detected so far. Pink is the input signal. Yellow is the signal after filtering.
Full walkthrough
HRF applied to a saw pad, a minor string progression, vocal harmonies, distorted guitar and a drum-and-bass mix bus, with every control explained.
How it helps
What HRF is good for
Track processing · Bus processing · Mix bus · Harmonic masking reduction · Tonal balance · Dynamic balance · Mastering · Finishing · Post-production · Sound design · Harmonic analysis
Cohesion and glue
Across a full mix or bus, HRF helps related sounds sit together more naturally by working with their shared harmonic structure. On a single source, it can strengthen the internal relationship between that sound’s own harmonics, helping it feel more coherent and complete.
Greater harmonic separation
HRF reduces masking between competing harmonic content, giving different elements more space and definition within a mix. On individual sounds, it can also reduce internal masking between harmonics, revealing more clarity, detail and tonal focus.
More balanced dynamics
HRF can redistribute energy across the dynamic range so sounds have more room to move instead of becoming crowded. This can help a full mix feel more open and expressive, while also improving the dynamic balance and movement within a single source.
Harmonic analysis and visualisation
Inspect a sound as well as process it. Pitch-class representation, spectrum view and 3D visualisations reveal how harmonic content is structured and how HRF is changing it.
A learning tool
Because you can both hear and see changes to harmonic content, HRF can also be used to explore harmonics, spectra, overtones and tonal relationships in real time.
Approachable at any level
Straightforward enough for bedroom musicians, yet detailed enough for experienced engineers who want precise control over individual tonal filters.
Specification
- Formats
- VST3, AU, AAX, standalone
- macOS
- 11 or later, Intel and Apple Silicon
- Windows
- 10 or later, 64-bit
- Sample rates
- 44.1 kHz to 192 kHz
- Licensing
- Perpetual, Rent-to-Own or Enterprise multi-seat
- Trial
- 28 days, fully featured, no payment details required
Pricing
Plans and subscriptions
Start with the 28-day trial. Choose a plan afterwards. Checkout and licence management run through our Moonbase store.
Individual
Perpetual licence, single seat
€129 one-time
$120 one-time
- —Yours to keep
- —All formats included
- —Updates within your version
Rent-to-Own
Single seat, billed monthly for a year
€14.49 per month
$12.49 per month
- —Payments build ownership
- —All updates included
- —Cancel any time
Enterprise
Perpetual multi-seat, 10 users
€1,113 one-time
$1,043 one-time
- —10 seats included
- —Central licence management
- —Invoice billing available
Need more than 10 seats? Contact us.
EUR prices include tax; USD prices are shown before tax. Your currency is confirmed at checkout.
Free 28-day trial
Fully featured, no payment details required. Educational and community-feedback discounts are also available — write to info@lumusictech.com.
Download the trialFeedback
Real people, honest feedback
Early testers and the Gearspace community have shaped HRF. A selection of what they told us.
“Glue or cohesion I've only really tried on mix bus so far. 5 out of 5 for harmonic enhancement and glue. Almost instantly. The sound is great.”
“I found HRF to work best on full mixes as a means of cleaning up frequency buildup in potentially undesirable areas.”
“Simple design, engaging visuals. Gave it more fullness.”
“Really liking what I'm hearing, must admit. Using it as a final polisher for my two main mix buses. It squeezes out that extra 10% from an already great mix and turns it into a truly finished work.”
“With HRF engaged, the vocal sounds more like the singer's real voice. The reverb is tucked away a little better too. It belongs in the same conversation as the well-known resonance tools, even though it's got its own thing going.”
“On the AG bus, the guitars just came slightly forward, sitting nicely in the mix. What's amazing is that it's doing the same thing to the drums. On bypass, they just don't sound as good anymore.”
“This does perform some clarity on a few masters I'm working on in a way that's different from the other tools I have. It's pretty easy to get a good result. Bought, and expect I will use this frequently.”
“It does something — very interesting. Out of all the betterizer type things I have tried, this one is different. It seems to solidify the track.”
“Definite finishing vibes. It tidies the top end and gives the whole thing a more finished feel without changing the character of the mix.”
FAQs
Straight answers
What does HRF do differently?+
It works from musical pitch. Rather than treating resonances by level alone, HRF follows the harmonic structure of what is playing—helping related content glue together more naturally, reducing masking so each element has more space, and redistributing energy for a more balanced and expressive dynamic range, both within individual sounds and across complete mixes.
How long is the trial?+
The trial runs 28 days. It is fully featured and requires no payment details.
Which formats are supported?+
VST3, AU and AAX, plus a standalone application. Windows 10 or later (64-bit) and macOS 11 or later, Intel or Apple Silicon.
Are there discounts?+
Yes. There is an educational discount for students and staff, and a community-feedback discount for people who have tested HRF and given us substantive feedback. Email us for either.