There are different ways to maximise the amount of detail you can retrieve within a certain sound. The first, and most common, is by just brightening the presentation – like turning on a strong fluorescent light. It’s effective, but it won’t necessarily be the most romantic setting for a date. The IEM-R4’s presentation is like walking over the hillside on a beautiful summer’s day. The sound is spacious, and all the detail is there – clear as day. But it comes with a natural touch. Not by lifting the treble, the easiest route; but by a high level of transparency and resolution. To do so, the R4 relies on its extraordinary treble extension.
A high level of transparency translates to extreme clarity in the articulation of a note, while retaining a natural tone. Once you strip a note from veil, even the finest of details doesn’t need to be bright or even loud, to be heard. Similarly, high resolution results in a more natural, realistic presentation, that feels more lifelike. The R4’s upper treble is not only very well extended, it’s very linear. The result – a very black background. While this might seem like an abstract audiophile term, it’s nevertheless an important construct. With an increasingly blacker background, the contrast between the tones and the background improves; a difference like painting white stripes on either a light grey or black board. In doing so, detail becomes more apparent because of the increasing contrast. As a result of these factors combined, the R4 marvels with the ease in which it presents its detail.
The R4’s impressive extension returns in its stage. While some cables affect the stage dimensions in various ways, in general the differences are relatively minor. Not in the case of the R4 – this is the widest stage I have experienced from a cable so far, with quite a safe margin. The stage opens up, and gains more room to breathe. While both height and depth increase, the difference isn’t as significant as its width. However, the layering ability improves, resulting in a more organised presentation. The spacious feel is augmented by the airiness of the stage, resulting from its controlled mid-bass. This is a bass that solely contributes itself in the form of instrument tones such as the bass player or kick drums, rather than a source of warm air on the stage. The R4’s separation benefits as a result. The fixation of the instrument positioning, the depth and layering; it all comes together in a vast, holographic image.
When it comes to tone, the R4 comes very close to neutral. But it’s the beautiful variation of neutral – one where there’s perfect harmony in the sound, balancing between warmth and light. Overall, the frequency response is very linear. There’s a slight bump in the 2-3 KHz range, resulting in a clear vocal presentation with a nice bit of body. And rather than lifting the treble, there’s a lift in the 5 KHz range followed by a slightly attenuated treble. The result is a clear yet very natural tone, with a smooth but articulate treble. Its midrange is warm, but only slightly warm – just a hint of warmth, essential for the naturalness of the tone.
The R4’s bass is fairly neutral, mirroring the source and iem in overall quantity. The bass impact is not enhanced, but as the sub-bass extension is very good, the hits reach deep. The balance between the sub- and mid-bass is very linear. Accordingly, the overall body of the bass is dense. When just the mid- or upper-bass is enhanced, a bass might have great quantity, but its nevertheless a fuzzy bass. The bass the R4 creates has good body, but it is also highly resolved. As a result, bass players sound more like a fellow instrument, rather than just a prominent source of warmth. Accordingly, the separation from the sub-bass is effective, bringing the mid-bass into the spotlight without needing to enhance its quantity. It’s a beautiful bass to behold, enjoyable for its musical contribution to the sound by means of its definition and true tone.
The midrange is slightly warm, although it isn’t warm enough to be classified as such. While there is an essential hint of naturalness throughout the presentation, overall, it comes very close to neutral. The lower midrange is slightly laidback, creating a compact but dense vocal presentation. The vocal positioning is fairly neutral. As it isn’t overly forward, it creates extra space on the stage. This results in an effective separation, especially when taking the stage dimensions into account. For instance, the IEM-R2 has a more prominent lower midrange, resulting in a fuller and more forward vocal presentation. The R4’s neutral stage position in turn creates a more open stage.
Similarly, the upper midrange mostly sounds clear, although it isn’t bright. As the treble isn’t enhanced, it isn’t particularly sparkly, but it doesn’t have to be – it gets its liveliness from its transparency, the purity of the sound. This isn’t the type of upper midrange that steers you towards electronic melodies, as the midrange isn’t brightened by a prominent treble. In fact, the naturalness of the presentation gives an analog feel, even to synthetic music; like a DJ went out of his way to manually record samples from actual instruments, rather than just pressing a button to reproduce them. There’s a certain realism to the music, that makes the music sound beautiful for just sounding true; that sweeping, romantic feel that a violin or piano should convey. There’s still a touch of sparkle to make string instruments like an acoustic guitar shine, but the focus is on the accuracy of the tone. That slightly warm accent provides an essential trueness, essential for conveying emotion.
Treble always has an intricately complicated role in a presentation. On the one hand it’s a necessity to add clarity and detail. But it’s also polarizing for listeners. Some desire the upfront detail, sense of pace, and overall sparkle a prominent treble can give. But for many others it’s a necessary evil, which needs to be contained as thoroughly as possible. As the R4 relies on its outstanding transparency and resolution for detail, it doesn’t require a brighter treble – the result of its outstanding top end extension.
The treble itself is very linear, resulting in an articulate but smooth performance. It’s not very often I listen to the treble to actually enjoy its tone. Not the sparkle or micro-detail – just a treble note itself. For a treble tone to sound accurate, it needs to have a slightly warmer tone. The naturalness of the R4’s presentation results from a slightly attenuated treble. This doesn’t mean the treble itself is laidback, as the clarity of the signature instead results from an upper midrange boost. But attenuating the treble itself results in more natural tone, akin to the treble tone of iems like Aether, UE18+ Pro, or Deca to name a few.