On the hardware side of things, the Quad Drivers utilize 3 balanced armature drivers in addition to a single carbon dynamic driver for a total of 4 drivers per ear. However, 1More have utilized a very unorthodox crossover method, dedicating the dynamic driver to both bass and midrange while delegating 2 armature drivers to high frequencies and the final armature driver to ultra-high frequencies. Through such a setup, the Quad Drivers achieve a more consistent sound from sources of varying output impedance and a slightly more coherent bass to midrange performance when compared to less integrated multi-driver earphones like the Sony XBA-40.
Of note, I did find the Quad Drivers to be quite bassy on first listen though after 150 hrs of burn-in, I did find them to become a little more balanced throughout, not surprising since the majority of the sound is produced by the dynamic driver. In all fairness, I was listening to the very neutral Hifiman RE-600 before hearing the Quad Driver, but I would surmise that the sound differences are a combination of both physical burn-in and some psychological adjustment. After some more extended listening, I have found the Quad Driver to be just modestly v-shaped; they aren’t neutral or even balanced, but provide an engaging consumer reference sound.
The Quad Drivers have a relatively low impedance of 32ohms combined with an average sensitivity of 99dB. As such, they did require a few more volume notches than the New Primacy and RE-600, they were similarly difficult to drive as the Pinnacle P1. The Quad Drivers definitely benefit from a nice source, they struggled from my iPod Nano with a considerable loss of soundstage space, air and separation and plugging them into my HTC 10 or Oppo HA-2 immediately yielded superior results. That being said, I did notice a much larger difference switching from the Nano to my HTC than switching from my HTC to my HA-2, the Quad Drivers were definitely intended to be driven by smartphones, given the nature of the driver array, and most modern smartphones should have no issue driving these earphones. The earphones remained quite tonally consistent, they were vastly less affected by output impedance than the Sony XBA-40’s but unevenness in the high end was prevalent on high impedance sources. The Quad Driver’s aren’t overly susceptible to hiss but will pick up small amounts on particularly noisy sources, on my HA-2 and Hidizs AP60, hiss was just audible but easily overpowered when music was playing.
I’ll admit that I’m a sucker for v-shaped earphones and the 1More Quad Driver is a well-executed example indeed. They aren’t quite as balanced as the New Primacy and are considerably more v-shaped than the slightly mid-forward RE-600 though they are also more balanced overall than the Pinnacle P1 which I found to have quite an aggressive upper-midrange/lower treble response and slightly scooped lower mids. In that regard, the Quad Driver retains plenty of balance to maintain genre versatility.
Soundstage, Imaging and Separation –
Being a vented, shallow fitting earphone, the Quad Drivers definitely hold an advantage over other sealed earphones in terms of soundstage performance offering an especially immersive performance. Booting up a live recording of Eric Clapton’s “Layla” and “Nobody Knows You When You’re Down and Out” and the most immediately noticeable aspect of the Quad Driver’s sound was their exemplary instrument separation. Great layering and delineation between instruments, vocals and audience produced a performance that handily bested the Pinnacle, RE-600 and even the more expensive New Primacy. In addition, impressive handling of complex passages flatter faster genres such as rock and electronic without sounding disjoint like the XBA-40. Soundstage space is also very impressive, especially depth which provides almost holographic projection of vocals and atmospheric effects. Of these earphones, the Pinnacle P1 had the most noticeably large soundstage, mainly in width, though the Quad Driver almost matches that out of the head width with far more depth, once again producing a more immersive sound. Imaging takes a bit of a hit due to the size and nature of the Quad Driver’s soundstage though centre image is quite strong and instrument placement is easily discerned; they just fail to match the incredibly sharp placement provided by the RE-600’s and New Primacy. Overall, if soundstage is a large priority, the Quad Driver is hard to beat within this price range, especially with regards to separation. Fans of classical, rock and electronic genres, in particular, will find much to love within the Quad Drivers tasteful v-shaped tuning and exceptional soundstage performance.
Bass is boosted, but is well done in terms of tuning. The bass boost is mostly focussed within deep/lower-bass with surprisingly balanced mid-bass and upper-bass responses. Though the earphones still have a slight mid-bass boost, the earphones don’t sound particularly thick or warm and the low-end has both nice clarity and a notable lack of bloat. Due to the nature of this bass boost, the Quad Drivers can sound slightly muddy and even tubby at times, especially in stark contrast to very neutral earphones like the RE-600, though I would still consider them to be relatively balanced throughout their low-end in the grand scheme of things; the Pinnacle P1, for instance, is similarly tubby if not slightly more so. Bass also isn’t ever present nor does it ever drone as with more mid-bass boosted earphones, allowing for greater transparency on vocal tracks. The Pinnacle P1 is a similarly impressive performer in regards to bass with just slightly less emphasis overall. However, the Pinnacle places its emphasis more in the mid-bass, sounding punchier but less natural as a result. Bass also reaches considerably deeper on the Quad Driver than the P1, and those that thought the P1 was missing rumble or slam will find that physical bass response with the Quad Driver without bass ever becoming overwhelming or loose. The RE-600 and New Primacy provide tighter bass responses than both, excelling with greater PRAT whilst retaining a similar amount of extension, if slightly more in the New Primacy’s case. In terms of tuning, the New Primacy has more of a sub-bass emphasis while the RE-600 has similar tuning to the Quad Driver albeit with vastly less quantity; it’s really a matter of taste, but I would definitely lean towards the Quad Driver and New Primacy as their tuning generally comes with the least compromises.
Otherwise, bass is articulate with really nice bass resolution and definition to each note, they actually sound quite similar to the Pinnacle in that regard, perhaps a factor of their exemplary soundstages. However, when listening to The Cranberries “Wanted”, each of those notes was missing some texture, especially evident in comparison to the outstanding Oriveti New Primacy and the leaner RE-600. That’s not to say that bass is slow or sloppy, the earphones had no issue keeping up with the fast basslines and rapidly transitioning tones of Michael Jackson and the Red Hot Chilli Peppers but that last bit of bass detail that I would expect at this price is missing. Still, the definition and clarity of bass notes are among the better earphones I have heard and when combined with the tasteful tuning, the Quad drivers rarely fail to impress; I think they’re a really well-performing earphone that provide no shortage of bass definition and slam without encroaching upon bass-head levels of quantity.
It may come as a surprise, but to my ear, the most impressive aspect of the Quad Driver’s audio performance is the midrange. It’s an evolution of the very balanced tone carried by 1More’s E1008, with greater clarity and resolution throughout. Breaking it down, the Quad Driver has quite a clear, balanced midrange that sits slightly behind the bass and treble but remains easily discernible and almost perfectly prominent. This is achieved via a moderate clarity boost and a slightly brighter tone. That being said, the midrange is very even, vocals are smooth if not quite as clean and sliky as the New Primacy, and this clear character remains consistent throughout the entire midrange. When compared to the RE-600, which I consider to be somewhat of a midrange benchmark, the Quad Driver had a similar emphasis on upper and lower midrange instruments though mids were considerably clearer and slightly fuller. Meanwhile, the New Primacy was even more full-bodied and slightly darker and the Pinnacle P1 was very aggressive though its upper midrange, sounding detailed and revealing but also a little unrefined and at times fatiguing. The Quad Driver sits in-between the New Primacy and RE-600 in terms of body, being slightly fuller than neutral but hardly thick or warm. Vocals are very clear with great layering and definition and clarity is fantastic without coming across as strident; the Quad Drivers have that smoother dynamic driver midrange tone, not unlike the Sennheiser ie800. This clarity does grant a slightly raspy tone to the midrange, especially with female vocals, though vocals never sound thing or overly artificial.
The Quad Driver is quite aggressively detailed, not to the extent of the more forward Sony XBA-40 and Pinnacle P1, but more so than the New Primacy with the RE-600 being even more laid-back. Listening to R.E.M.’s “The Sidewinder Sleeps Tonight” and Indigo Girl’s “Sugar Tongue” and the Quad Driver impresses with great clarity and detail to acoustic guitar plucks and strums, revealing small intricacies that the more laid-back RE-600 tended to skip over while sounding more natural than the, even more, detail forward Pinnacle P1. The New Primacy did tend to resolve more detail though it is also a smoother earphone that places details more in the background with the Quad Driver sounding more engaging and excited. Similarly, listening to Modest House’s “Float On” and the Quad Drivers provided a reproduction with very nice midrange resolution and layering. Due to their v-shaped tuning, vocals were more recessed than the other earphones I’ve mentioned in this review though the Pinnacles were similarly recessed due to their thicker midrange and brighter tonal balance which pushes lower mids a little further behind in the mix. Still, all of these earphones provided pleasing intimacy to vocals though I did prefer the presentation of the RE-600’s and New Primacy’s which provided a little more balance to this slightly mid-recessed track and a little more raw detail and coherency. The Quad Driver ultimately produces a very clear, layered midrange with great resolution and very good detail retrieval that is edged out only by the most exemplary earphones around this price range such as the slightly more expensive New Primacy. Being v-shaped, vocals are slightly recessed, though the midrange is more even than most v-shaped earphones like the Pinnacles and their clear character means that midrange notes are never overshadowed.
Despite having such a comprehensive treble driver array, I didn’t find the Quad Driver to hold any significant advantage over the Pinnacle, New Primacy or even RE-600 in regards to high-frequency performance. They do depart from the New Primacy and RE-600 in terms of tuning, with more similarity to earphones such as the ie800 and Sony XBA-40. A middle treble boost around 8KHz imbues the sound with aggressive detailing and clarity but also slight irregularity to treble, resulting in a loss of detail and some coherency issues (tested from a low output impedance source). The RE-600 and New Primacy, though more laid-back do sound more coherent and linear in the highs which contribute to their fantastic detail retrieval though the Quad Driver does have slightly better top end extension and a lack of any high-end roll-off. Once again, I found the Quad Driver to be more linear than the Pinnacle though the P1 also produced considerably more treble sparkle and was slightly more detailed. Despite this, I still prefer the Quad Driver for long-term listening and their aggressive, slightly forward treble response combined with their expansive soundstage and stellar separation creates an intoxicating sound with great air and shimmer.
But coming back to that uneven middle treble spike, I do feel that the Quad Drivers produce some harshness on treble-forward songs such as Radiohead’s “Creep”. That being said, treble does behave itself, for the most part, producing a well-detailed and textured sound that flatters cymbals, electric guitar, and atmospheric effects. When listening to Creep, the Quad Driver produced a nice rendition with cymbals sounding extended and well-bodied. On the contrary, the Pinnacle sounded slightly thin and splashy but also resolved slightly more detail in the upper registers while the more linear New Primacy and RE-600 both resolved more texture to each treble note along with a cleaner presentation than both the P1 and Quad Driver. Similar impressions carry over when listening to Queen’s “Killer Queen” where the Quad Driver was appropriately revealing and crisp with nice clarity to the finger snapping within the intro and high-hats throughout the chorus without sounding overly like wood sticks. The RE-600 immediately impressed with a very even treble response that provided more insight into those snaps though cymbals and high-hats were more rolled-off, losing out air and shimmer. The New Primacy was similarly revealing to the RE-600 while maintaining a natural tone and had no issue with extension apart from a slight roll-off at the very top. So I do think that Quad Driver is a nice sounding earphone though due to the nature of 1More’s treble boost, the can sound a little disjointed at times. More neutral earphones like the RE-600 do have noticeably more detail in the lower treble region along with more texture to high-notes. The 1More’s redeem themselves through greater extension, a lack of any roll-off and a slightly forward sense of detail and clarity that infuses the sound with excitement and energy without being quite as grating as either the Sony XBA-40 or Meeaudio Pinnacle P1.
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