The OAE2 is Grell Audio’s latest pair of headphones. Thanks to an innovative design and unconventional engineering choices, they aim to reproduce the kind of natural, non-fatiguing sound typically associated with listening to a pair of loudspeakers.
Grell Audio is a young company founded in 2022 by Alex Grell, one of the world’s most renowned audio engineers and the designer behind several legendary Sennheiser headphones that have become true cult classics among audiophiles. Among the models designed by Alex Grell are the HD 580, HD 650, HD 800, and the extremely expensive Orpheus. After leaving Sennheiser, he founded his new company together with other industry experts with the goal of developing innovative headphones through original engineering solutions and unconventional technical approaches. Their objective is to create products that better match the natural characteristics of human hearing, delivering a more realistic and lifelike listening experience.
Prodotti consigliati
Features and Technologies
We had the pleasure of spending an extended period listening to the Grell OAE2, Grell’s new open-back over-ear headphones, whose design incorporates several truly unique concepts.
The OAE2 is built around three carefully engineered acoustic principles designed to work together. These include the so-called Front-sided Sound Field Modulation (FSFM), a specially developed damping system, and an unconventional acoustic structure featuring angled drivers mounted within a large, curved open baffle.
Front-sided Sound Field Modulation (FSFM) is an innovative concept that is virtually unique in today’s headphone industry and was previously implemented in Grell’s OAE1 as well. According to this principle, the sound produced by the headphones is shaped around the listener’s individual ear anatomy.
Human hearing naturally perceives sound most accurately when it arrives from the front. When a sound originates elsewhere, our instinct is to turn our head toward its source. Taking advantage of this characteristic, the FSFM technology positions the drivers at a forward angle relative to the ears, allowing the sound waves to reach the listener as if they were coming from loudspeakers placed in front of them.
Furthermore, each listener’s unique ear shape contributes to shaping the frequency response of the sound before it reaches the eardrum. The result is reproduction that is as natural, accurate, and coloration-free as possible, with richly detailed yet remarkably non-fatiguing midrange and treble frequencies.
The specially developed damping system is the result of extensive testing across a wide range of acoustic materials. It has been engineered to provide bass reproduction that is deep, controlled, and exceptionally accurate.
The acoustic driver is the true technological heart of the OAE2. It features a relatively compact 40 mm biocellulose diaphragm mounted at a forward angle that simulates the listening position of a pair of stereo loudspeakers inside a room, while leaving a large curved open area within the baffle.
This design allows sound waves to propagate more naturally, reducing the reflections typically generated by acoustically enclosed surfaces. The baffle itself is covered by a high-precision stainless-steel mesh manufactured in Germany, which contributes to defining the system’s acoustic impedance. As a result, the balance between bass and treble is optimized while maintaining precise low-frequency control and minimizing unwanted resonances and tonal coloration.
Main Specifications
- Frequency response: 12–34,000 Hz (-3 dB), 6–46,000 Hz (-10 dB)
- Driver type: Dynamic
- Nominal impedance: 38 Ohms
- Sound pressure level: 100 dB at 1 kHz, 1 VRMS
- Weight (without cable): 378 g
The Grell OAE2 is available for around €500 directly from Grell’s website or through various authorized retailers, including Thomann in Italy. This places it in what could be considered the entry point of the mid-range headphone market.
Given its unusual design philosophy, we were genuinely eager to find out how these headphones would perform.
Accessories, Cables and Connectivity
The Grell OAE2 comes in a sturdy cardboard box and includes a generous selection of accessories: a travel case, two 1.8-meter cables (one terminated with a balanced 4.4 mm plug and the other with a 3.5 mm plug plus a 6.35 mm adapter), as well as a large, full-color instruction manual that is both comprehensive and exceptionally well produced.
Straight out of the box, the headphones feel solidly built and elegantly designed. Once worn, they prove to be remarkably comfortable despite being relatively heavy for this type of headphone.
We should point out, however, that we had to extend the headband to its maximum length to achieve a proper fit. People with a particularly large head, above-average height, or very thick hair may find the headphones somewhat tight or too short, so this is something worth considering before purchasing. For listeners of average to above-average build, however, we encountered no fitting issues whatsoever.
The silver-plated OFC copper cables are of excellent quality and feature a rather unusual connection system on the headphone side: a single 2.5 mm stereo plug that can be connected to either the left or the right earcup. The recessed connector, however, is not particularly convenient to use and gives the impression of being somewhat delicate.
Overall, the accessory package is impressive, and the attention devoted to the product’s presentation is clearly evident.
As for the single-sided cable design, there are both advantages and disadvantages. On the positive side, having only one cable connected to a single earcup provides a noticeably greater sense of freedom during wired listening, making the experience more comfortable than expected. On the downside, however, you’ll need to take good care of the supplied cables because, due to their proprietary characteristics—including the recessed 2.5 mm input connector—you won’t be able to replace them with just any aftermarket cable you may already own.
How Does the OAE2 Sound?
Let’s move on to our listening impressions.
We tested the OAE2 with several headphone amplifiers and DACs available during our review, including the HiFiMAN EF400, EF500, and Serenade Jr, the Fosi Audio ZD3, ZH3, and GR70, as well as an older Beresford Caiman Seg. We also had the opportunity to compare it directly with several similarly priced HiFiMAN headphones, along with models such as the Fosi Audio i5 and the Grado SR80e.
@amplificalo Grell Audio OAE2 Unboxing video /// Review coming soon Follow us for more! #headphones #hifi @grell ♬ audio originale – Amplificalo
From the very first minutes of listening, the OAE2 immediately distinguishes itself through its exceptionally natural and utterly non-fatiguing sound signature.
Thanks to bass performance that is remarkably substantial for an open-back headphone, a beautifully balanced midrange that renders both vocals and instruments with striking realism, and treble that never becomes excessively aggressive, the OAE2 may not be the ideal choice for listeners seeking the utmost level of transparency or microscopic detail, or for those accustomed to headphones with an emphasized upper-midrange presentation.
Instead, it will delight anyone looking to spend hours immersed in music that feels lively, dynamic, exceptionally well balanced, and convincingly realistic.
Overall, the OAE2 comes across as less analytical than many competitors in its price range. Rather than chasing the last ounce of detail retrieval, it focuses on delivering an engaging, highly musical, and thoroughly enjoyable listening experience.
The headphone’s distinctive FSFM construction is probably responsible for the particularly natural perception of high frequencies. The treble integrates seamlessly with the rest of the frequency spectrum, remaining detailed without ever becoming harsh or fatiguing.
Another aspect we were especially curious about was the reproduction of the soundstage. Grell claims that the OAE2 is capable of approaching the listening experience of a high-quality pair of stereo loudspeakers.
The resulting presentation is undoubtedly distinctive and may require a short period of adjustment, especially after listening to more conventional headphones. Vocals and instruments tend to appear in front of the listener, relatively close rather than far away, and only rarely seem to originate from inside the head or far off to the sides.
Image precision and instrument separation are outstanding for a headphone in this price range. The soundstage, however, is not as wide as that of headphones featuring a more pronounced upper-midrange and treble emphasis.
We should emphasize one point mentioned in the user manual: it may be necessary to experiment with the position of the earcups on your ears in order to achieve the intended effect. This is not merely a suggestion—it is genuinely essential.
Because of the technologies employed, moving the earcups back by as little as two millimeters can significantly alter the perceived soundstage. Fortunately, finding the optimal position is quick, intuitive, and even rather enjoyable.
DAC and Amplifier Pairing
When it comes to pairing the OAE2 with different DACs and headphone amplifiers, we found it to be remarkably versatile. It performs well with every source we tested and proves equally convincing across virtually every musical genre.
Given its natural, smooth, and non-fatiguing tuning, the OAE2 pairs particularly well with modern, highly transparent and revealing headphone DAC/amplifiers based on AKM or ESS DAC chips. At the same time, warmer-sounding equipment—such as the HiFiMAN Serenade Jr.—further enhances the headphone’s musicality, resulting in an even richer and more engaging listening experience.
Despite its relatively low 38-ohm impedance, the OAE2 has moderately low sensitivity, meaning that it requires a reasonable amount of power to perform at its best.
Fortunately, virtually all modern desktop headphone DAC/amplifiers should have no difficulty driving it properly. Portable devices, however, deserve a little more attention, as they may not always provide sufficient output power.
In any case, this is an open-back headphone with virtually no acoustic isolation, making it unsuitable for use on the go or in noisy environments.
Conclusions
The Grell OAE2 is, in many respects, a headphone unlike most others currently on the market.
Its defining characteristic is an exceptionally natural sound signature. While it may not be the ultimate choice for listeners whose highest priority is absolute resolution or microscopic detail retrieval, it delivers a presentation that is musical, engaging, and emotionally involving.
Perhaps its greatest strength—and one that deserves to be emphasized—is that it never becomes fatiguing, even during extended listening sessions. This makes the OAE2 an excellent choice for anyone who enjoys spending hours immersed in music without experiencing listening fatigue.
The unique technologies employed in its design, starting with Front-sided Sound Field Modulation (FSFM), make a tangible contribution to the headphone’s natural presentation and help recreate a listening experience that more closely resembles that of a high-quality pair of loudspeakers.
Because of its distinctive sonic character, we recommend auditioning the OAE2 before purchasing whenever possible. Its presentation differs noticeably from that of most conventional headphones, and prospective buyers may appreciate experiencing its unique approach firsthand.
That said, even without an audition, the OAE2 is unlikely to disappoint anyone looking for headphones capable of delivering a realistic, natural sound that remains enjoyable and fatigue-free over countless hours of listening.
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