Open-back headphones for mixing and mastering with beryllium drivers and USC individual calibration plug-ins
The Ollo Audio X2 are open-back studio headphones designed for those who make EQ and compression decisions in 1 dB increments. They combine a new driver with a beryllium-coated diaphragm and calibration specific to each individual unit, developed together to achieve the most linear response possible. Handcrafted with American walnut ear cups, they provide a reliable reference regardless of your control room’s acoustics—from mixing and mastering to sound design.
The X2’s 50 mm dynamic driver uses a PET diaphragm with a PVD-applied beryllium coating and polyurethane. Beryllium is much stiffer than previously used materials: the driver responds faster and with greater accuracy, transients come through cleaner, and subtle variations become audible.
In practice, a 1- or 2-dB gain reduction on the compressor is no longer a guess—you can actually hear it. The same goes for EQ when you cut or boost by 1 dB. You’re working on the finer details, and the driver is capable of reproducing your choices with the same precision with which you make them.
The driver’s rigidity also has another benefit: the X2s quickly reach a good sound pressure level, so you can work at moderate volumes while still picking up every 1- or 2-dB detail. Less auditory fatigue and an accurate listening experience even at low levels.
It makes no sense to make 1-dB EQ adjustments on headphones with 3-dB tolerances. That’s why every X2 is individually measured during quality control: Unit Specific Calibration (USC) corrects for small deviations caused by the material tolerances of that specific unit and brings the response to within approximately 1 dB of the selected target—beyond what can be achieved through acoustic design alone.
The neutral and balanced sound of the X2 stems first and foremost from its acoustics: plug them in, and they’re ready to record and mix. Calibration comes into play at a second level, refining what physical acoustics alone cannot correct, without forcing the drivers into extreme compensations. Together, they ensure the most linear response possible for your unit, even when room acoustics prevent the monitors from achieving it.
The USC file contains readable, unencrypted EQ data in XPS format: no subscriptions, no closed ecosystem, no ties to specific software. The calibration data belongs to you, and you can import it into any DAW EQ, correction plug-in, or DSP interface. It’s also printed inside the package, so you always have it on hand when working in an external studio—no need to install software or ask for an administrator password.
Using your X2’s serial number, download the USC file and import it into the included USC plug-in, available in VST, AU, AAX, and standalone formats for Mac and Windows. You can insert it on the DAW’s master bus—remembering to bypass it before bouncing—or use it in system-wide mode with solutions like Rogue Amoeba’s SoundSource on macOS.
USC data can also be used with Realphones (full integration), Sonarworks (via a custom target), Morphit, Waves Nx, and any plug-in equipped with an EQ. On the hardware side, they work with RME TotalMix, UA Apollo via UAD Console, ARC ON Ear, MOTU Pro Audio Control, Neumann (MT48 and Anubis), Metric Halo MIO Console, and, more generally, with any output equipped with an EQ, including monitor controllers such as the Metric Halo ULN or RME ADI-2 Pro FX.
The X2s are handcrafted from American walnut, aluminum, stainless steel, synthetic leather, and silicone. When parts wear out, you can easily replace them at home with common tools: the drivers, synthetic leather headband, and harmonic steel headband are all replaceable. The 5-year limited warranty confirms their suitability as a tool for everyday use.
The self-adjusting headband and 360° rotating ear cups ensure an instant, comfortable fit, even when sharing the headphones with others in the studio. The clamping force is calibrated to achieve the target response on the standard ear simulator. The 2-meter silicone cable, with an enameled OFC copper core, connects to the headphones via two mini-XLR connectors and terminates with a 3.5 mm jack and a 6.3 mm screw-on adapter.
The driver is mounted eccentrically and at an angle within a conical chassis, delivering a soundstage that faithfully reproduces the positions of instruments in both stereo projects and immersive projects played back in binaural mode. Front-to-back pressure equalization is controlled by an 11.8 acoustic ohm Saati flow resistor, and the left and right drivers are matched to a tolerance of ±1 dB.
Technical Specifications
Impedance
32 ohm
Headphone Type
Open-back
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