DISCLAIMER
I would like to thank HIFIGO for providing this review unit.
The Celest Relentless can be gotten here: https://hifigo.com/products/kinera-celest-relentless (no affiliate links).
INTRODUCTION
For folks that are interested in a little ancient Chinese mythology, the "Relentless" namesake used for this IEM is actually from a touching story of a legendary guardian bird:
SPECIFICATIONS
ACCESSORIES
Other than the IEM, these are included:
- 3 pairs of Celest 221 "vocal" silicone eartips (S/M/L/)
- 3 pairs of Celest 608 "balanced" silicone eartips (S/M/L)
- 2 pairs of foam tips (M/L)
- Cable
- Modular plugs for 3.5 mm and 4.4 mm
- Metal bookmark
- Carrying case
- Cleaning brush
For a $100ish USD set, the accessories are very generous; essentially, everything that an audiophile would require is covered.
The black Celest 221 tips are wide-bore and they boost treble and soundstage. The red Celest 608 are narrow-bore, and these increase bass, though with some stage compression. The foam tips provide the best isolation, albeit with a attenuation of the treble frequencies.
The stock copper silver-plated cable is well-braided and tangle-free, with minimal microphonics. There's a chin cinch for added grip. It comes with options for 3.5 mm (single-ended) and 4.4 mm (balanced) modules, depending on your source preference. A nice touch is that the distal terminal has a screw on design, so that the module doesn't inadvertently drop out during usage, which is something not uncommon in flimsy modular cables which are just plug-on.
The metal bookmark, as detailed above in this tragic story of the guardian deity bird, dovetails (no pun intended) beautifully with the Relentless moniker.
Last but note least, we have a practical cleaning brush and a square leatherette semi-rigid case. The case is tough externally, with webbing and a soft material internally to cushion the contents.
The rest of this review was done with the stock cable and stock narrow-bore Celest 608 silicone tips. No aftermarket accessories were used, so as not to add any confounders to the sound.
BUILD/COMFORT
The housings are fashioned from HeyGears 3D-printed dermatologically-friendly resin. The faceplates are individually hand-painted, so each earpiece is unique! These faceplates showcase feathers of the guardian bird, coupled with waves of the tumultuous East China Sea, as per this storied narrative.
The shells are semi-transparent, allowing consumers to visualize the acoustic tubing and drivers!
While on the larger side to accommodate 7 drivers per shell, the housings are light, and I had no issues using the Relentless for longer listening sessions. The inner aspects are smooth with no awkward protrusions.
I did not encounter any driver flex on my pair. Isolation is slightly above average, and this IEM can be used in noisy places without much penalties.
INTERNALS
The Relentless is a 7 driver setup, comprised of the following configuration:
DRIVABILITY
I tested the Relentless with the following sources:
- Apple dongle
- Cayin RU7
- Chord Mojo 2
- Fiio KA11 dongle
- Fiio KA17 dongle
- Khadas Tone Board -> Schiit Asgard 3 amp
- Questyle M15 DAC/AMP dongle
- Sony Walkman NW A-55 DAP (Walkman One WM1Z Plus v2 Mod)
- Sony Walkman NW A-55 DAP (Walkman One Neutral Mod)
- Sony Walkman NW WM1A DAP (Walkman One WM1Z Plus v2 Mod)
- Smartphone
This IEM has moderate drivability requirements. It is not an extremely easy IEM to drive, and will scale slightly with amplification, in terms of headroom and dynamics.
SOUND & TECHNICALITIES
Graph of the Celest Relentless via IEC711 coupler.
Tonally, the Relentless sports a bright V-shaped tuning. It promises an exciting listening session, melding a big fun bass with a well-extended and resolving treble. This is in contrast to Celest's usual darker house sound.
This is a mid-bass focused set, with bass north of neutral, but just a bit shy of bona fide basshead levels. There's decent sub-bass rumble and an impactful mid-bass. The bass is surprisingly textured, with nimble speed and just a slight smattering of mid-bass bleed.
As per its V-shaped signature, the lower midrange is recessed to some extent, though thankfully there is no huge bass encroachment, so this frequency band remains relatively transparent. Upper mids hit about 8 dB ear gain, and vocals are forwards without pushing into overt shouty territory.
The Relentless has a bright treble, furnishing lots of resolution and clarity, with lots of air. This IEM will be a blessing for trebleheads for sure, though we do run into some instances of sibilance. Thankfully, for the treble-sensitive amongst us, this region can be tamed somewhat with the foam or narrow-bore silicone tips, in addition to perhaps using a warmer source or not playing the Relentless at high volumes (Fletcher Munson curve).
There's just a minor whiff of BA timbre, and for a set that packs so many BAs, timbral accuracy is surprisingly decent. Note weight is a tinge on the lighter side, but by and large, acoustic instruments and vocals sound quite natural (don't be expecting single DD levels of timbre of course).
Technical chops on the Relentless are quite something, with a huge soundstage, well-layered instrument separation and superb micro-detailing. The Relentless has one of the better soundstages for a $100ish IEM, with sound projecting quite far beyond the ears in width, with good depth and height to boot. Imaging is relatively accurate and transients are crisp.
COMPARISONS
The Relentless will be compared against other midFI hybrids. Single DDs, multi-BAs, and planars are left out as the different driver types have their pros and cons.
Binary X Gizaudio Chopin
The Chopin is a U-shaped set with a mammoth lower midrange/lower mids scoop out. Thus, the Chopin sounds much thinner and anemic in this area, with an artificial metallic timbre.
In technical aspects, the Chopin has a more claustrophobic soundstage, with weaker imaging and micro-detailing. The Chopin also has unique tear drop shaped shells which may possibly pose fitting issues.
Penon Fan 2
The Fan 2 is tuned warm neutral. It has a linear bass (with less quantity), though it has a thicker and lusher midrange than the Relentless. The Fan 2's treble is blunted, with some loss of resolution. The Fan 2 is however, more sedate and less sibilant in the treble. Of note, the Fan 2 is inferior in soundstage, micro-detailing and imaging.
Many consumers complain about fitting issues with the Fan 2's long nozzles, so this might be a potential deal-breaker.
CONCLUSIONS
The Celest Relentless is one of the better $100ish hybrids one can get their paws on as of the time of writing. It compares very favourably against some similarly priced hybrid rivals, beating them in technicalities.
Segueing seamlessly into this poignant and stirring chronicle of the legendary guardian Relentless bird, this IEM has well-matched - and generous - accessories, elegant faceplates and comfortable ergonomics.
Bestowing a bright V-shaped signature, the Relentless has excellent technical chops, in particular micro-detailing and soundstage are the stars of the show. The bass has a good mix of quantity and quality, with a very resolving and extended treble making this the perfect set for trebleheads and detail-freaks. To top it off, timbre is surprisingly natural for something containing so many BAs.
It may be a tinge spicy for our treble-sensitive friends, but thankfully the treble region can be mitigated with foam tips or warmer source pairing or even playback at non-high levels (as per the Fletcher Munson curve). The midrange is a wee bit depressed - as per V-shaped style tuning - so mid-lovers might want to look for something else that beefs up the lower midrange more. However, it has to be said, the Relentless is not as anemic-sounding as something like the Binary Audio Chopin, which has a way more concave lower-midrange.
All things considered, the Relentless gets my recommendation for folks who are looking for a solid entry-level V-shaped midFI hybrid, which is beautiful on the inside and outside.
I would like to thank HIFIGO for providing this review unit.
The Celest Relentless can be gotten here: https://hifigo.com/products/kinera-celest-relentless (no affiliate links).
INTRODUCTION
For folks that are interested in a little ancient Chinese mythology, the "Relentless" namesake used for this IEM is actually from a touching story of a legendary guardian bird:
This legend hails from the ancient Chinese tome of the Classic of Mountains and Seas: https://en.wikipedia.org/wiki/Jingwei
In bygone times, a girl named Nüwa drowned while swimming in the East China sea. Thereafter, she was reborn into a spirit guardian bird called Jingwei.
This diety bird swore to not let her tragic fate befall anyone else, and everyday, she picked up twigs and rocks in her beak from a nearby mountain, in an attempt to deposit these into the sea. The bird was determined to fill up the sea, one stone at a time!
Concluding the story, the sea mocked her, saying that she will never succeed in a million years. Jingwei replied stoically that she will spend ten million years - even a hundred million years - to accomplish her dying wish of not letting anyone else perish in the same manner. Thus came about the Chinese idiom of Jīngwèi tián hǎi (精衛填海) - which translates to relentless resolve even in the face of hopeless odds.
In fact, as we will read below, this IEM's shells and packaging feature a beautiful sea wave motif - in addition to a golden bookmark of the Jingwei bird - tying in nicely with this heart-rending folk story.
In bygone times, a girl named Nüwa drowned while swimming in the East China sea. Thereafter, she was reborn into a spirit guardian bird called Jingwei.
This diety bird swore to not let her tragic fate befall anyone else, and everyday, she picked up twigs and rocks in her beak from a nearby mountain, in an attempt to deposit these into the sea. The bird was determined to fill up the sea, one stone at a time!
Concluding the story, the sea mocked her, saying that she will never succeed in a million years. Jingwei replied stoically that she will spend ten million years - even a hundred million years - to accomplish her dying wish of not letting anyone else perish in the same manner. Thus came about the Chinese idiom of Jīngwèi tián hǎi (精衛填海) - which translates to relentless resolve even in the face of hopeless odds.
In fact, as we will read below, this IEM's shells and packaging feature a beautiful sea wave motif - in addition to a golden bookmark of the Jingwei bird - tying in nicely with this heart-rending folk story.
SPECIFICATIONS
- Driver configuration: 8 mm dynamic driver + 2 x 29689 balanced armature drivers + 4 x 10012 balanced armature drivers
- Frequency response: 20 Hz - 20 kHz
- Impedance: 27 Ω
- Sensitivity: 105 dB
- Cable: 2-pin, 0.78 mm; 5N copper silver-plated cable; modules for 3.5 mm and 4.4 mm terminals
ACCESSORIES
Other than the IEM, these are included:
- 3 pairs of Celest 221 "vocal" silicone eartips (S/M/L/)
- 3 pairs of Celest 608 "balanced" silicone eartips (S/M/L)
- 2 pairs of foam tips (M/L)
- Cable
- Modular plugs for 3.5 mm and 4.4 mm
- Metal bookmark
- Carrying case
- Cleaning brush
For a $100ish USD set, the accessories are very generous; essentially, everything that an audiophile would require is covered.
The black Celest 221 tips are wide-bore and they boost treble and soundstage. The red Celest 608 are narrow-bore, and these increase bass, though with some stage compression. The foam tips provide the best isolation, albeit with a attenuation of the treble frequencies.
The stock copper silver-plated cable is well-braided and tangle-free, with minimal microphonics. There's a chin cinch for added grip. It comes with options for 3.5 mm (single-ended) and 4.4 mm (balanced) modules, depending on your source preference. A nice touch is that the distal terminal has a screw on design, so that the module doesn't inadvertently drop out during usage, which is something not uncommon in flimsy modular cables which are just plug-on.
The metal bookmark, as detailed above in this tragic story of the guardian deity bird, dovetails (no pun intended) beautifully with the Relentless moniker.
Last but note least, we have a practical cleaning brush and a square leatherette semi-rigid case. The case is tough externally, with webbing and a soft material internally to cushion the contents.
The rest of this review was done with the stock cable and stock narrow-bore Celest 608 silicone tips. No aftermarket accessories were used, so as not to add any confounders to the sound.
BUILD/COMFORT
The housings are fashioned from HeyGears 3D-printed dermatologically-friendly resin. The faceplates are individually hand-painted, so each earpiece is unique! These faceplates showcase feathers of the guardian bird, coupled with waves of the tumultuous East China Sea, as per this storied narrative.
The shells are semi-transparent, allowing consumers to visualize the acoustic tubing and drivers!
While on the larger side to accommodate 7 drivers per shell, the housings are light, and I had no issues using the Relentless for longer listening sessions. The inner aspects are smooth with no awkward protrusions.
I did not encounter any driver flex on my pair. Isolation is slightly above average, and this IEM can be used in noisy places without much penalties.
INTERNALS
The Relentless is a 7 driver setup, comprised of the following configuration:
- 1x 8 mm dynamic driver takes care of the bass and midrange.
- 2 x 29689 BAs settle the lower treble
- 4 x 10012 BAs handle the upper treble
DRIVABILITY
I tested the Relentless with the following sources:
- Apple dongle
- Cayin RU7
- Chord Mojo 2
- Fiio KA11 dongle
- Fiio KA17 dongle
- Khadas Tone Board -> Schiit Asgard 3 amp
- Questyle M15 DAC/AMP dongle
- Sony Walkman NW A-55 DAP (Walkman One WM1Z Plus v2 Mod)
- Sony Walkman NW A-55 DAP (Walkman One Neutral Mod)
- Sony Walkman NW WM1A DAP (Walkman One WM1Z Plus v2 Mod)
- Smartphone
This IEM has moderate drivability requirements. It is not an extremely easy IEM to drive, and will scale slightly with amplification, in terms of headroom and dynamics.
SOUND & TECHNICALITIES
Graph of the Celest Relentless via IEC711 coupler.
Tonally, the Relentless sports a bright V-shaped tuning. It promises an exciting listening session, melding a big fun bass with a well-extended and resolving treble. This is in contrast to Celest's usual darker house sound.
This is a mid-bass focused set, with bass north of neutral, but just a bit shy of bona fide basshead levels. There's decent sub-bass rumble and an impactful mid-bass. The bass is surprisingly textured, with nimble speed and just a slight smattering of mid-bass bleed.
As per its V-shaped signature, the lower midrange is recessed to some extent, though thankfully there is no huge bass encroachment, so this frequency band remains relatively transparent. Upper mids hit about 8 dB ear gain, and vocals are forwards without pushing into overt shouty territory.
The Relentless has a bright treble, furnishing lots of resolution and clarity, with lots of air. This IEM will be a blessing for trebleheads for sure, though we do run into some instances of sibilance. Thankfully, for the treble-sensitive amongst us, this region can be tamed somewhat with the foam or narrow-bore silicone tips, in addition to perhaps using a warmer source or not playing the Relentless at high volumes (Fletcher Munson curve).
There's just a minor whiff of BA timbre, and for a set that packs so many BAs, timbral accuracy is surprisingly decent. Note weight is a tinge on the lighter side, but by and large, acoustic instruments and vocals sound quite natural (don't be expecting single DD levels of timbre of course).
Technical chops on the Relentless are quite something, with a huge soundstage, well-layered instrument separation and superb micro-detailing. The Relentless has one of the better soundstages for a $100ish IEM, with sound projecting quite far beyond the ears in width, with good depth and height to boot. Imaging is relatively accurate and transients are crisp.
COMPARISONS
The Relentless will be compared against other midFI hybrids. Single DDs, multi-BAs, and planars are left out as the different driver types have their pros and cons.
Binary X Gizaudio Chopin
The Chopin is a U-shaped set with a mammoth lower midrange/lower mids scoop out. Thus, the Chopin sounds much thinner and anemic in this area, with an artificial metallic timbre.
In technical aspects, the Chopin has a more claustrophobic soundstage, with weaker imaging and micro-detailing. The Chopin also has unique tear drop shaped shells which may possibly pose fitting issues.
Penon Fan 2
The Fan 2 is tuned warm neutral. It has a linear bass (with less quantity), though it has a thicker and lusher midrange than the Relentless. The Fan 2's treble is blunted, with some loss of resolution. The Fan 2 is however, more sedate and less sibilant in the treble. Of note, the Fan 2 is inferior in soundstage, micro-detailing and imaging.
Many consumers complain about fitting issues with the Fan 2's long nozzles, so this might be a potential deal-breaker.
CONCLUSIONS
The Celest Relentless is one of the better $100ish hybrids one can get their paws on as of the time of writing. It compares very favourably against some similarly priced hybrid rivals, beating them in technicalities.
Segueing seamlessly into this poignant and stirring chronicle of the legendary guardian Relentless bird, this IEM has well-matched - and generous - accessories, elegant faceplates and comfortable ergonomics.
Bestowing a bright V-shaped signature, the Relentless has excellent technical chops, in particular micro-detailing and soundstage are the stars of the show. The bass has a good mix of quantity and quality, with a very resolving and extended treble making this the perfect set for trebleheads and detail-freaks. To top it off, timbre is surprisingly natural for something containing so many BAs.
It may be a tinge spicy for our treble-sensitive friends, but thankfully the treble region can be mitigated with foam tips or warmer source pairing or even playback at non-high levels (as per the Fletcher Munson curve). The midrange is a wee bit depressed - as per V-shaped style tuning - so mid-lovers might want to look for something else that beefs up the lower midrange more. However, it has to be said, the Relentless is not as anemic-sounding as something like the Binary Audio Chopin, which has a way more concave lower-midrange.
All things considered, the Relentless gets my recommendation for folks who are looking for a solid entry-level V-shaped midFI hybrid, which is beautiful on the inside and outside.