Head-Fi reviews the Ollo Audio X1

The Ollo Audio X1 has been reviewed on Head-Fi, with a detailed look at its build quality, comfort, USC II calibration system, sound character, measurements, repairability, and value.

The review describes the X1 as a “warm, detailed studio reference” and frames it around a simple idea: studio reference headphones are not only tools for engineers. They can also become a way of understanding music more deeply — almost like listening through the decisions of the mixer and producer behind the record.

“Few headphones make the case for that idea as compelling as the Ollo Audio X1.”

For us, that is close to the heart of what X1 was made for. Not just to sound impressive for a few seconds, and not to flatter everything into something polished before the work has actually been done. X1 was designed as an open-back studio reference headphone for people who need to hear what is there, make decisions, and trust those decisions outside one room or one playback system.

A handcrafted build that feels deliberate

One of the first things the review highlights is the physical build of the X1. The reviewer describes the first impression as one of “genuine artisan manufacture”, pointing to the American walnut earcups, the finish, the structure, and the sense that the headphone has been made with visible care.

The review also notes that the American walnut earcups are CNC-machined from a single piece of wood, with a warmth and presence that moulded plastic or anodised aluminium cannot replicate. The reviewer describes the grain and finish as something that suggests care in selection rather than random batch processing.

“This is a headphone that looks as considered as its engineering claims to be.”

That matters because studio tools live hard lives. They sit on desks, move between rooms, get packed into bags, passed between hands, and used for long sessions where comfort, durability, and trust matter more than surface-level design tricks.

The review also points to the X1’s solid feel in hand. The stainless steel headband and walnut construction give the headphone a sense of durability that fits a real studio environment, where tools are used daily and need to hold up over time.

At 416g, the X1 is not the lightest headphone in the open-back studio category. But the reviewer also notes that the elastic strap distributes the weight well, the earcup depth is generous, and the overall fit became better after a few days of use.

Built to be repaired, not discarded

Repairability is another major part of the review. The reviewer spends time on the removable earcups, visible screws, accessible components, and the fact that the X1 is designed to be opened, serviced, and kept in use.

“This is a headphone built to be repaired, not discarded.”

The review also mentions that components such as drivers, backplates, sockets, earpads, and headband are available as spare parts directly from OLLO Audio.

That has always been part of the OLLO approach. A professional tool should not become useless because one part wears out. Ear pads will eventually need replacing. Cables live real lives. Studio gear gets used. The point is not to pretend nothing will ever wear down, but to make sure the product can keep working when it does.

The reviewer describes OLLO’s commitment to user serviceability as both rare and practically meaningful. That phrase matters, because repairability is not just a nice sustainability message. It is practical. It means less waste, less downtime, and a product that can stay with the user beyond the usual replacement cycle.

USC II calibration: measured for your specific pair

The review also gives a lot of attention to the USC II calibration system included with the X1.

Each X1 comes with a calibration profile derived from measurements of that specific pair. In the review, this is described as something rare and valuable, because driver variation within a production run is real. Correcting at the individual unit level gives the listener a more precise starting point than a generic correction curve.

“The fact that the calibration file is a compensation file for your specific unit is something that you rarely see.”

The reviewer also highlights the way USC II lets the user apply calibration with an intensity slider from 0–100%, rather than forcing a simple on/off decision. That means you can blend the corrected and native response instead of being locked into one version of the headphone.

The review describes this as a thoughtful implementation, and goes further by saying that the USC II system gives the X1 a degree of control that fixed-response headphones cannot offer.

Beyond calibration, the review mentions the different USC II listening modes: Flat, Studio, Car, Spatial, and Harman target. It also notes mixing utilities such as mono/stereo soloing and EQ tilt control.

The reviewer writes that the modes allow the listener to hear the same recording through a different interpretive lens — useful whether mixing or simply listening for pleasure.

“None of these are gimmicks. They are tools that let you hear the same recording through a different interpretive lens.”

Warm, detailed, and more engaging than expected

The sound section of the review is especially interesting because the reviewer hears the X1 as more than a purely clinical studio tool.

They describe its overall character as warm and detailed — “closer to an engaged, musical listen than the clinical monitor presentation the ‘studio reference’ category might imply.” They also point out that the X1’s native tuning sits somewhat differently from what the words “studio reference” might lead you to expect, with a more musically engaging, texturally warm-neutral character.

At the same time, the review makes a clear distinction between the X1’s native sound and its calibrated use. The provided personalised calibration brings the sound back toward a more neutral tuning, giving the listener a way to move between the X1’s natural character and a stricter reference presentation.

The bass is described as slightly warm, with kick drums and bass lines carrying satisfying body and weight without crossing into bloom or looseness. The reviewer also notes clean texture in the bass region, with bass guitar lines and acoustic double bass rendered with genuine articulation.

For the treble, the review says the X1 is extended and airy without becoming etched, glassy, or fatiguing. It avoids the upper-harmonic aggression that can make some studio headphones tiring over longer sessions, while still retaining enough air and shimmer for cymbals and high-frequency transients.

But the strongest praise is reserved for the midrange.

“The midrange is the X1’s most accomplished region, and the aspect of the sound that most clearly distinguishes it from competitors at similar prices.”

The reviewer describes vocal timbre as convincing and immediate, with voices sitting close and naturally present. Instrument separation is described as precise without becoming forensic, and acoustic instruments are said to carry enough note weight and body to give recordings a sense of physical reality.

That kind of language matters because it points to the real use of a reference headphone. Detail alone is not enough. The question is whether a headphone helps reveal texture, movement, tone, and intent without forcing the listener into a tiring, hyper-analytical state.

In the review, this is where the X1 seems to land: detailed enough to be useful, warm enough to remain human, and revealing enough to make familiar recordings feel newly present.

Soundstage, imaging, and angled drivers

The Head-Fi review also looks at soundstage and imaging. The X1’s open-back design and angled 50mm driver are described as contributing to a soundstage that is consistently good for a studio headphone.

The reviewer notes clear left-right separation, a well-defined centre image, and convincing depth layering. For complex recordings, the sense of front-to-back distance between instruments is described as more convincing than the price might suggest.

This links directly to one of the physical design choices of the X1: the angled driver orientation. The angled 50mm driver is deliberate, aimed at improved stereo imaging and a more natural soundstage presentation compared with a driver mounted perpendicular to the ear.

For mixing, producing, and reference listening, this kind of spatial behaviour matters. It helps the listener understand placement, depth, and relationships between elements rather than only hearing frequency balance.

Measurements and calibration

The measurements section of the review supports many of the listening impressions. The reviewer describes the frequency response as a warm-neutral tuning, with good channel matching and treble extension that avoids anything too dramatic or sibilant.

The review also compares the raw and calibrated response. According to the reviewer, the calibration fills in the 1kHz–2kHz region and lowers the lower midrange slightly, bringing the overall tonality closer to neutral.

Again, the important point is not just that X1 has a native character. It is the individual USC II calibration that gives the listener another layer of control over that character.

“The response is warm rather than strictly flat, and the individual calibration in USC II brings this closer to the target — the combination of native character and software correction gives you a degree of control over the presentation that fixed-response headphones cannot offer.”

The distortion measurements also receive strong praise. The reviewer describes them as genuinely excellent, noting that distortion remains well-controlled even in the demanding low-frequency range where dynamic drivers typically show the most stress.

“The distortion measurements are genuinely excellent and explain part of the X1’s character under real musical conditions.”

Compared with other studio reference headphones

The Head-Fi review also places the X1 alongside several other open-back studio reference headphones, including the Sony MDR-MV1, Sennheiser HD490 Pro, Audeze MM-100, HEDD D1, and Meze 109 Pro.

The comparisons are useful because they show where the X1 sits in the current studio reference landscape. The X1 is not described as the lightest or the most strictly analytical headphone in the group. Instead, it is presented as a headphone with its own combination of handcrafted build, warm-neutral tuning, midrange richness, individual calibration, repairability, and value.

Against the HEDD D1, the X1 is described as warmer and more organic, while the D1 is described as drier and more forensic. Against the Meze 109 Pro, the X1 is described as having greater midrange presence and harmonic richness. Against the Sony MDR-MV1, the X1 is described as more involving, while the Sony is lighter and more neutral. Against the Sennheiser HD490 Pro, the review presents the choice as one between ergonomic ease and a cooler analytical presentation on one side, and tonal warmth plus calibration depth on the other. Against the Audeze MM-100, the review frames the X1 as more musically engaging in midrange texture, while the MM-100 makes a stronger technical case for bass and transient handling.

The X1 does not try to be everything. It is not just another neutral open-back studio headphone. It offers a specific combination of sound, build, calibration, serviceability, and long-term ownership.

Value and long-term ownership

One of the strongest parts of the review is the value assessment. The reviewer points to the price of €539, the handmade wooden build, the individual unit calibration, the five-year warranty, user serviceability, and the 90-day money-back guarantee.

“The price rating of five needs little justification: at €539 for a handmade, artisanal wooden headphone with individual unit calibration, a five-year warranty, full user serviceability, and a 90-day money-back guarantee, the X1 is priced with genuine restraint.”

That sentence captures something important. X1 is not just a product built around sound. It is also built around ownership. The calibration, warranty, repairability, spare parts, and trial all matter because they shape the long-term experience of using the headphone.

For studio tools, that matters. A headphone is not only something you hear for a few minutes in a shop. It becomes part of the way you work, check, adjust, and listen. It sits with you through decisions. It becomes part of your reference system.

A headphone for reference and pleasure

The conclusion of the Head-Fi review brings the review back to something simple: the X1 made the reviewer listen to music differently.

That is not a small compliment. A headphone can be accurate and still leave the listener unmoved. It can be enjoyable and still hide too much. The most interesting tools often sit somewhere more difficult: they reveal, but they do not flatten the experience. They show detail, but they do not turn music into a technical exercise.

“The Ollo Audio X1 made me listen to my music collection differently, which is a high compliment for any headphone.”

The reviewer says the warmth and midrange presence of the X1 gave familiar recordings a textural engagement they had not heard through other references in their collection. They also say the USC II calibration system provided a meaningful additional layer of control for sessions where strict accuracy mattered more than enjoyment.

That dual use is exactly where the X1 becomes interesting. It is not only for the moment when you are working. It is also for the moment when you want to understand a record more deeply. The same qualities that help with reference listening — detail, imaging, midrange information, low distortion, calibration — can also make music feel more present.

“For the listener who wants a handcrafted, individually calibrated, user-serviceable open-back headphone that reveals musical detail without sacrificing the pleasure of listening — and who is willing to have patience with the fit while the clamping force softens with use — the Ollo Audio X1 is a remarkable product at a price that is very difficult to fault.”

The final line of the review says it plainly:

“Buy it if you want to rediscover your music collection through ears that are simultaneously more honest and more musical than most.”

For us, that is a strong summary of what X1 is trying to do. It is not about making everything sound bigger, shinier, or easier than it is. It is about giving you a clear, detailed, and usable reference — one that still leaves the music alive.

If you want to read the full review, including the complete measurements, images, unboxing notes, and comparisons with the Sony MDR-MV1, Sennheiser HD490 Pro, Audeze MM-100, HEDD D1, and Meze 109 Pro, you can find it on Head-Fi.

Read the full review on Head-Fi