AudioQuest might be best known as a cable manufacturer but it has been making considerable headway in the computer audio and headphone markets. Following the success of its Dragonfly USB DAC/headphone amp, the company officially launched its first ever headphone. Enlisting the services of Skylar Gray (ex-Westone) to design from scratch with purpose-built components never before used in headphone construction, AudioQuest’s objective was to make a minimum distortion, tonally linear earspeaker that “bridges the gap between the pursuit of unbridled pleasure and unprocessed truth” and offers an “immersive, emotionally compelling, non-fatiguing listening experience”. The product of this financially unconstrained remit is Nighthawk, a semi-open back headphone priced at £499 that looks and sounds like few others on the market.
An enormous amount of R&D has gone into Nighthawk. There are numerous engineering firsts on display, some of which are based on unorthodox posits. Discussing them all is beyond the scope of this review, so I will focus on the most interesting ones and direct info-maniacs to the Nighthawk website which goes to great lengths to explain its design and the (in places controversial) rationale that underpins it.
Let’s tackle the controversy first: Nighthawk’s drivers. Instead of reaching for Mylar, the material of choice for almost every headphone maker, AudioQuest has engineered a unit that they claim is far closer in function and performance to a conventional loudspeaker. Nighthawk’s self-damping drivers employ a biocellulose diaphragm, proper voice-coil former, compliant rubber surround and patented split-gap motor. And are claimed to be capable of high and precision-controlled excursion with “true pistonic motion” and thus exceptionally low distortion. This is a feat that AQ argues mylar is incapable of due to its inherent flimsiness, and the consequently non-linear distortion at frequencies from 2kHz to 10kHz is blamed for the “artificially boosted highs” that exist in “most headphones”. It should be cautioned however that much of AudioQuest’s discussion centres around comparison with a single unnamed but apparently “highly regarded flagship model”.
The earcups that house the drivers are also an engineering first. They are made from “liquid wood”, an intriguing, natural and sustainable composite of wood and plant fibre that is injection molded with exceptional accuracy. Not only beautiful in appearance, it is also asserted to be acoustically superior to conventional plastic or wood. The semi-open back grilles represent more innovation in the form of a 3D-printed diamond cubic lattice inspired by the structure of butterfly wings. These not only vent the earcups but also act as diffusers by trapping and dispersing sound waves to minimise reflections and resonances. Isolation from environmental noise is, as you may expect, somewhere between conventional open- and closed-back designs.
Nighthawk is structurally supported by a steel frame that provides a secure fit with low clamp pressure. Four elastomer bands suspend each earcup from the yoke. A patent-pending suspension system similar to that used in microphone cradles to provide isolation from mechanical vibration, in Nighthawk they also allow precise positioning of the earcups to the listener’s head independent of the yokes, improving performance and comfort. The frame does not actually rest on the head, it floats above the self-adjusting and very comfortable headband. This comprises a resistance band inside a padded leather and suede jacket, the headband smoothly stretches to fit the wearer’s head and distributes Nighthawk’s 350g weight evenly. The earpads are fashioned from “protein leather”, a bio-derived synthetic fabric chosen for both its durability and skin-like softness, and are extremely comfortable.
Electrical connection via 2.5mm sockets at the base of each earcup means Nighthawk is capable of balanced operation. It currently ships with two detachable 8ft long cables, neither of which incidentally are balanced! (A stock Nighthawk XLR-terminated cable is however in development.) The thicker of the two cables is based on AudioQuest’s popular Castle Rock loudspeaker wire and features “high-purity Solid Perfect-Surface Copper+ (PSC+) conductors in a Double Star-Quad configuration” with silver plated terminations, which according to its maker provides superior clarity, dynamic contrast and lower distortion. A “less sophisticated” second cable is included on practical grounds, as its thinner and more flexible construction makes it better suited to the rigours of portable use. To my ears, the PSC+ version is clearly the superior of the two cables and should be used whenever practical. The basic cable would however be my preference for travel as, despite being longer than desired for this purpose, it is noticeably less microphonic.
AudioQuest explicitly recommends exercising its nocturnal raptor for at least 150 hours before assessing its performance. It is not unusual for a headphone’s sonic presentation to change during its initial period of use before it plateaus, and I can confirm that Nighthawk benefits from the recommended break-in period; after which its tonal balance and soundstage is significantly less coloured and more expansive. A 25-ohm impedance and 100dB/mW sensitivity makes this headphone a very easy load for portable devices to drive cleanly to uncomfortably loud SPLs, with plenty of juice left in reserve. What’s more, it has been intentionally engineered to present a remarkably flat impedance curve across its entire frequency range, which its maker claims minimises its susceptibility to sonic deviations presented by different headphone amps, thus maximising compatibility. I can nevertheless reveal that Nighthawk is still a transducer that scales impressively with superior sources and very much responds to the attributes of the amplifier it is paired with.
Drive it with the onboard amp of an iPod or MacBook laptop, for instance, and Nighthawk’s warm V shaped sonic profile is very evident; so much that it initially sounds quite murky and bloated until your brain adjusts to this headphone’s wholesome flavour. Nighthawk’s rich, velvety, and intoxicatingly heady delivery soon had me conjuring images of the nation’s favourite dark Irish stout. As pleasant as this indulgent beery fantasy was, I struggled to accept Nighthawk’s tonality which was so different from my - and I suspect many other listeners’ - personal reference sound; a reference influenced by the many great headphones of past and present. The warm and laid-back character was not the result of a rolled-off top octave. Nighthawk’s highs are in fact remarkably linear, extended and resolving, and the leading edges of sibilants and transients are rendered very crisply. It was instead due to a shallow but broad trough in the ‘presence’ region, the frequencies that our ears are particularly sensitive to. Vocals, strings, piano, and percussive strikes were consequently mellowed and did not project with the attack that many headphone enthusiasts are used to. An extended and gently rising low end was also apparent, adding heft and warmth and intensifying this headphone’s rich and euphonic tone. As this rise began relatively high up the scale, it sometimes caused instances of smearing. Despite exhibiting endearingly woody timbres for the most part, lower registers of the male voice could, for example, sound too thick and wooly and lack separation from other bassy instruments.
Upgrade from the onboard electronics in portable devices - even merely to a low-cost outboard option - and Nighthawk’s performance is improved, becoming more neutral and resolute. Driven by Schiit Audio’s USB-powered Fulla DAC/Amp dongle, the headphone’s overall disposition is less sunken and congealed. Lows are grippier and speedier whilst retaining their smooth extension, musicality and palpability. Thanks in part to this now better behaved low end, mids grow in presence and fluidity but are neither thrust forward nor brightened to the extent that their moreish laid-back warmth is sacrificed. Vocals, for example, gain more clearance from other instruments in the bass section but retain their charming woody timbre, only now the texture is more like “liquid wood”, if you’ll excuse the pun. Fulla exhibits a slight hardness in its reproduction of lower treble frequencies, which can induce listener fatigue if paired with an inherently bright headphone. Irrespective of the partnering amplification used however, Nighthawk demonstrated a welcome absence of mid-to-high frequency glare and grain which made the majority of my source material sound delightful. Even aggressively compressed modern productions did not inflict anywhere near the amount of aural displeasure they normally would. Yet this headphone manages to reveal a satisfying level of detail, particularly when driven by a quality standalone DAC and headphone amplifier, which enables it to be used for critical listening.
Unsurprisingly, scaling also improves the spatial aspects of Nighthawk’s presentation. Skylar Gray’s unique semi-open back design facilitates a convincing soundstage of appreciable depth and width, but the true extent of this dimensionality was not revealed until the headphone was paired with high quality separates. Nighthawk may struggle to pull off the unearthly ‘out-of-head’ 3D holography trick that some of the best open backs can accomplish, and is therefore perhaps more similar to a great closed back design in this respect, but it is very spatially cohesive and delivers reassuringly solid imaging. More loudspeaker-like in its placement of instruments, it rarely reveals unnaturally localised ‘holes’ in the soundstage. As detail is delivered in a subtler manner, instead of one that draws immediate and perhaps undue attention, Nighthawk is an excellent choice for listeners longing to emerge free from aural fatigue after an immersive late-night music binge. Its warm and mildly asymmetrical V shaped sonic flavour does however make it best matched with a source that leans to the forward and grippy side of neutrality.
I have to applaud AudioQuest’s boldness in entering the high-end headphone market with a model that is so radically different in design and sound to any other currently available. Bucking the trend so boldly is sure to divide audio enthusiasts. Listeners who enjoy an immersive, rich sound with crisp highs, smooth laid-back mids, and lush flowing bass notes are sure to succumb to Nighthawk’s euphonic late-night caress. Those with a preference for a lighter, speedier delivery with more bite and accentuated spaciousness may find that this nocturnal bird drifts too far from home. The undecided would be wise to give this unique headphone an extended listen - not just a cursory one - to learn if they can be persuaded to Skylar Gray’s way of thinking. After being initially underwhelmed, I have very much come to appreciate the more forgiving listening experience Nighthawk offers over its brighter and more analytical sounding peers. AudioQuest’s debut earspeaker may not be most listeners’ instinctual pick, but by challenging the entrenched ‘audiophile’ headphone sound we have been conditioned to accept, the niche Nighthawk has made for itself in an overcrowded market is wholly justified.
Ancillaries used during testing
Stationary system/s: Mac Mini 2010 + Schiit Bifrost Uber + Yamaha A-S2000 / Schiit Valhalla.
Portable system/s: iPod Touch (onboard amp/DAC); MacBook Air (onboard amp/DAC); MacBook Air + Schiit Fulla.
Reference headphones: Sennheiser HD600.
Read Nighthawk designer Skylar Gray's comments on this review.
Impedance: 25 ohms
Sensitivity: 100dB SPL/mW
Power Handling: 1.5W
Driver: 50mm Dynamic | Biocellulose Diaphragm | 1.2T Split-Gap Motor
Cable length: 8ft (2.4m)
Conductors: Solid Perfect-Surface Copper+ (PSC+)
Geometry: Symmetric Star-Quad
NDS: Noise-Dissipation System
Terminations: 3.5mm Stereo > Dual 2.5mm Mono | Direct-Silver Plated Copper
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