Select comparisons
Custom Art FIBAE 5 ($999). In my recent FIBAE 5 review I summed up Custom Art’s new tribrid custom IEM as ‘the consummate kilobuck all-rounder’, and Zeta doesn’t change that assessment.
Although I consider Zeta a more enjoyable IEM, FIBAE 5 takes an evenhanded approach to its tuning that will likely win broader appeal. FIBAE 5 combines bass that’s punchy but not quite as authoritative as Zeta’s, a clear but slightly softer and thinner midrange, and a treble that’s more extended and present, if a little peaky at times.
Zeta is a more accomplished technical performer, though you might argue that FIBAE’s cleaner midrange and planar treble give it a slight clarity edge. FIBAE 5 is comparatively conservative and relaxed, with Zeta more engaging, lively and fun.
As a package, Zeta ships with a better cable, nicer accessories, and while it’s difficult to compare a titanium-shelled universal IEM to a work-of-art resin custom, Zeta just about shades FIBAE 5’s still exceptional build quality for me.
Campfire Audio Supermoon ($1500). Another custom IEM I reviewed a short while ago, Campfire’s Supermoon is still the most technically gifted IEM I’ve heard in its price range, and while its tonality is far more divisive, for the music it plays well with, it has a unique sound that’s hard to beat.
Despite sporting a single planar dynamic driver, compared to Zeta, Supermoon is more resolving and quite a bit faster, though it lacks the dynamic contrast and punch of Zeta’s beautifully-tuned dynamic driver. Stage size is similar on both, with Supermoon perhaps a touch wider, and it’s hard to beat Supermoon’s instrument and vocal separation at this level, in my opinion.
Tonally I find Zeta’s balance and warmth more natural and organic than Supermoon’s ‘digital’ presentation. That’s not necessarily a mark against Supermoon, especially for those who prefer their sound cleaner and leaner, and both IEMs share an innate musicality that steers well wide of analytical. There’s no question that Zeta has the more accurate timbre, more realistic voicing, and significantly thicker note weight, especially in the upper midrange and treble registers.
As with FIBAE 5, it’s difficult to compare build and fit between Zeta and Supermoon. At this level, both are excellent, as well-made as any I’ve seen at any price tier. I do prefer Supermoon’s thinner, lighter and more ergonomic cable, and since I generally prefer MMCX connectors to 2-pin, Supermoon gets my nod here too. I know that’s not a popular opinion, though, so you might find the opposite to be true.
Sony IER-Z1R ($1,799). Sony’s peerless flagship is, to me, as fresh today as it was when it made its debut five years ago. Regardless of price, I’m yet to hear an IEM that delivers Z1R’s unique combination of liquid sub-bass, pristine female vocal clarity and pitch-perfect treble, inside a cavernous stage that presents the most lifelike, life-size soundscape I’ve heard in portable audio to date.
In Zeta, I’ve found an IEM that shares some of Z1R’s tonal traits, but mixes them up with its own flavour. Zeta has more midbass drive than Z1R, giving its bass a weightier, heavier and punchier character to Z1R’s textured, nuanced sub-focused rumble. Zeta’s midrange is audibly more forward than Z1R’s, especially male vocals, though Z1R still somehow edges Zeta for absolute clarity.
Where Zeta’s treble is sibilance-free and more relaxed, the Sony’s is more direct, incisive and clean, with a sparkle that’s truly class-leading. Some find Z1R’s treble too splashy with high-energy music, so picking between the two treble presentations will come down to preference. I find that both work equally well with most of my library.
Technically, Z1R is a step up from Zeta, which as I mentioned above, lacks very little in most departments. Z1R is tuned for clarity, whereas Zeta is slightly fuller and warmer, with thicker note weight. Z1R is more resolving, more precise, more open, painting with a finer brush as it were. That said, both sound lifelike and realistic, despite these differences.
Very few IEM manufacturers can challenge Sony from a packaging and build quality perspective, and HiBy is no different. Many will find Zeta an easier fit, however, with lighter and more ergonomic shells, but I’m one of the lucky few for whom Z1R fits like a glove (with the right tips, of course). As pretty and shiny as they are, Z1R’s Zirconium shells are also prone to micro scratches, which Zeta’s coated titanium alloy shells don’t seem to be.
Overall, the best compliment I can give Zeta in this comparison is that I have no hesitation picking it alongside Z1R to get the same level of enjoyment, especially from bass and vocals. Make of that what you will, but know that I can count on one hand the number of other IEMs I can say that about.
Select pairings
Zeta is a warm-sounding IEM for sure, but it’s not dark, nor veiled or dry. It’s also not so warm that it doesn’t play well with warm-leaning sources. It has great synergy with all my DAPs, all of which are warmer than neutral, but if you prefer a more neutral, lighter or brighter sound, the combination of Zeta and brighter sources may be more to your liking.
HiBy RS8. HiBy’s flagship DAP, RS8 features a pleasant warm-of-neutral tonality with a distinctly analogue-sounding R2R character, and amplification that elevates it to the top of the portable player technical performance charts too. To me it feels like Zeta was tuned with RS8 in mind, and I wouldn’t be surprised if some of the marketing materials from HiBy featuring the pairing were taken long before Zeta was a known entity.
Since RS8 is my baseline for Zeta’s sound, I can only compare it to other sources by proxy. Everything I’ve described about Zeta to this point is drawn mainly from my experience of it with RS8. Zeta does change its profile to some degree with different sources, but to me achieves an almost perfect symbiosis of sound and function – including the minor MSEB tweaks I touched on in the review – with RS8.
iBasso DX300 MAX. I recently purchased iBasso’s ‘flagship’ DAP as a replacement for the last of my desktop sources, wanting a transportable alternative with desktop-grade driving power for my IEMs. In the DX300 MAX I found what I was after, along with a smooth, slightly warm and somewhat organic sound profile despite its delta sigma DAC.
The biggest difference I hear with the DX300 Max with Zeta is its absolutely effortless bass control. Bass notes are tighter, and land with more impact compared to RS8 – which is itself a superb bass performer. ‘3MAX’ takes bass control to a different level, separating it even further from the other frequencies while sharpening its focus and resolution. Where it doesn’t quite match RS8 is in vocal purity, although I find Zeta’s midrange better-resolved and slightly cleaner with the iBasso.
I also hear Zeta’s treble to be a touch more relaxed and ethereal with the DX300 MAX compared to RS8. It’s also more resolving, with a grander stage in all dimensions.
Sony WM1Z. There’s something to be said about Sony synergy, which is the main reason I bought Sony’s ‘gold brick’ to pair with Z1R, but I’m happy to say it’s equally at home with Zeta.
Some might tell you to steer clear of warmer sources like WM1Z with Zeta, but I personally don’t find Sony’s flagship (non-Android) Walkman to be skewed too warm in the first place. Instead, I find that unique combination of excitable yet rich, smooth and expansive Sony house sound to work well with Zeta’s natural tonality.
I also don’t hear Zeta’s bass as elevated any further than it is with RS8, which is to say tastefully elevated but not overdone for my preferences. In some ways it hits harder than RS8, but doesn’t have quite the same resolving power as the HiBy, or the delicate control of the 3MAX. Midrange notes are clear and concise, reminiscent of the 3MAX, while treble is given a touch more bite than the HiBy and iBasso, making Zeta sound a touch more excitable.
Like Z1R, some say Sony’s Walkman is showing its age, but I still find it to be competitive at the highest level with modern DAPs, and given fresh sounding, easily-driven IEMs like Zeta, very much has a place in any collection where streaming and Android functionality are not a priority.
Continue to closing thoughts…
