A Parametric EQ With Personality
Undertone Audio has delivered a unique parametric EQ with amazing tonal shaping and character. The MPEQ-1 feels like Eric Valentine took bits and pieces of his favorite hardware and rolled it into this amazing exploratory EQ. While using it, it’s easy to forget you’re using an EQ because its use case takes you on this journey of EQ, tone shaper that is highly musical, like playing an instrument.
First impressions
The MPEQ 1 comes across as one of those rare EQs that immediately pushes you into shaping sound rather than “fixing” it. On the surface it looks like a standard analog model — fixed bands, HP/LP filters, boost/cut switches — but once you start turning knobs, it becomes obvious this thing is built for sculpting tone in ways most EQs don’t attempt.
EQ Band
The fixed bands behave like classic hardware: limited ranges, musical curves, and a notch mode that can get surgical when you need it. But the real personality comes from Shape control. It’s not just a bell to shelf morph — it’s a continuous curve designer that lets you create weird hybrid shapes you’d normally need multiple bands to achieve. It’s the kind of control that makes you rethink how many EQ moves you actually need.
Harmonics
Then there’s the harmonic section, which is where the plugin stops behaving like an EQ and starts behaving like a tone machine. Each band can drive its own distortion — tube, solid state, or a smoother algorithm — and the interaction between EQ curves and harmonics is where the magic happens. You’re not just brightening up a drum kit; you’re energizing it. You’re not just fixing a bass midrange; you’re reshaping the entire feel of the instrument.
Inputs/Outputs
The input/output link is a small but crucial detail — you can push the unit hard without the level jumping all over the place. Combined with the built in hardware harmonics and per band distortion, it encourages you to drive the plugin like actual gear.
Workflow
In practice, the MPEQ 1 changes how you approach sound. Instead of stacking EQs and saturators, you start thinking about curves and harmonics simultaneously. It’s less about correction and more about momentum — shaping sounds like a living thing.
I could not use multiple instances of this EQ on my older Windows 10 setup as the CPU kept spiking. So, bouncing tracks is a good workaround. However, I had no issues with my newer W11 laptop with gaming specs.
Recap
If you like pushing gear, software past its sonically designed purpose, this EQ is for you. If you like breaking the rules, this EQ is for you. The MPEQ-1 takes you out of conventional comfort zones and forces you to both feel and hear sound differently.
Pros
- Breaks all the rules: Encourages creative misuse; every knob feels like an invitation to experiment.
- Saturation: Harmonics behave musically, not destructively — adds weight without mud.
- Shape control: Morphs curves in ways that make traditional EQs feel static.
- Workflow: Inspires bold moves early in the mix, not just polish at the end.
- 14 Day Trial.
Cons
- Learning curve: The Shape and harmonic sections demand time to understand.
- CPU load: Heavy processing when multiple instances run.
- No visual feedback: You rely on ears, not meters — great for purists, tricky for beginners.
Alternatives
- FabFiltter Pro Q 4.
- FabFilter Saturn.
- Soundtoys.
Final Thought
Undertone Audio MPEQ-1 is impressive. It erased any thought I had before this review of it being just another EQ. The Interface is incredible, the controls make sense, and it sounds amazing. Give it a try and it will find a place in your sound toolkit.