DISCLAIMER
I would like to thank the Linsoul for providing this review unit.
The 7Hz Aurora can be gotten here:
https://www.linsoul.com/products/7hz-aurora (no affiliate links).
SPECIFICATIONS
Driver configuration: 1 x 12 mm composite diaphragm dynamic driver + 2 x custom balanced armature drivers + 1 x 6 mm micro-planar driver
Frequency response: 5 Hz - 40 kHz
Impedance: 30 Ω
Sensitivity: 105 dB/V @ 1 kHz
Cable: 2-pin, 0.78 mm; single-crystal copper cable; 3.5 mm and 4.4 mm modular terminals
Tested at: $399 USD
ACCESSORIES
Other than the IEM, these are included:
- 4 pairs of 7Hz H07 silicone eartips
- 3 pairs of long nozzle silicone eartips
- Plastic case for eartips
- Cable
- Cable terminations for 3.5 mm and 4.4 mm modules
- Carrying case
The accessory spread is generous, and definitely befitting of a MidFI IEM.
While no foam tips are included, we have 2 variants of silicone tips. First up, we have 4 pairs of 7Hz H07 silicone tips - which are short-bore - and these present a balanced signature. Interestingly, 7Hz has debuted a long-nozzle eartip - which looks similar to the DUNU S&S types; these are also extremely balanced in sonics, but with improved soundstaging and isolation.
These S&S doppelgangers are my favourite pairing, as they furnish an expansive soundsage without overly boosting any part of the frequency response. However, they have longer nozzles and a sticky feel, and are not as soft in the ears as the other H07 silicone tips. The eartips come in their own plastic case, which is a nice touch.
We have a 2-pin single-crystal copper cable provided, and this comes with distal 3.5 mm and 4.4 mm modular terminals, for pairing with single-ended and balanced sources, depending on your needs. This cable is well-braided and thick, with minimal microphonics. A chin cinch is added for practicality, and the L-shaped terminals are useful during field-use.
Last but not least, we have an ovoid leatherette carrying case. The innards have webbing and soft cushioning, while the externals are tough enough to withstand compressive forces.
The rest of this review was done with the stock cable and stock long nozzle silicone tips. No aftermarket accessories were used, so as not to add any confounders to the sound.
BUILD/COMFORT
The housings are fashioned from 3D-printed medical-grade resin. The faceplates contain titanium filaments, which are unique to each housing - thus consumers will get their own individualized IEM so to speak. The shells have a mirror-like, psychedelic and colourful tiger-striped motif, which is certainly eye-catching. They may be prone to smudging, but build quality is top-notch.
The earpieces are quite large to house the numerous drivers. Thankfully, despite the bigger dimensions, comfort is still agreeable, due to the mere 5 g weight of each side. I had no issues wearing the Aurora for hour long sessions, with the smooth inner surfaces not poking the ears.
With the long-nozzle S&S look-alike tips installed, isolation is above average. I did not find any driver flex on my pair, which is a sign of good acoustic airflow.
INTERNALS
The Aurora is a tribrid, boasting of the following eclectic configuration with a 3-way cross-over:
- 1 x 12 mm composite diaphragm dynamic driver
- 2 x custom balanced armature drivers
- 1 x 6 mm micro-planar driver
The DD handles the bass, with the pair of BAs covering the full range. The micro-planar settles the upper treble.
DRIVABILITY
I tested the Aurora 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 is moderately easy to drive. While weaker sources may juice it, the Aurora does benefit from amplification, in terms of soundstage, dynamics and bass control.
SOUND & TECHNICALITIES
Graph of the 7Hz Aurora via IEC711 coupler.
Tonally, the Aurora showcases a U-shaped, balanced sonic profile. This is quite genre agnostic, and should cover most consumer demands.
This is a sub-
bass focused IEM. Bass extends deeply, with good rumble felt. However, it is not a bona fide basshead IEM in terms of sheer quantity. Quality-wise, the Aurora provides a textured, fast and tight bass, with not an ounce of mid-bass bleed. Even with complex bass tracks, the Aurora handles these with aplomb; case in point, for Sting's Englishman In New York, the Aurora aces the fast double bass solo in the middle of the track, where many other sets may fall apart.
The lower
midrange is a tinge recessed, but this frequency band is very transparent and clean due to no bass impingement. This allows excellent layering and pinpointing of instruments and vocals on a dark background. On graphs, there appears to be a peak at the 3ish kHz region - I personally hate over-zealous upper mids - but on actual listening at moderate volumes (as per the Fletcher Munson curve), I found this region forwards without overt shoutiness, which is a tough line to balance. This slight peak actually furnishes clarity and resolution without being an ice-pick, and as we will read below, the technicalities on this IEM are top-notch.
The Aurora has good
treble sparkle, but once again, this area is nicely balanced, in bestowing air but not veering to harshness. Sibilance is minimal, and the Aurora manages to get cymbal strikes and high-hat hits just right - they are present but not jarring. Of note, there's a 6/7 kHz dip in the treble which is something of a trade-secret used in TOTL tuning to decrease sibilance and splashiness without overly damping resolution.
As alluded to, the Aurora is a
technicalities champ. Micro-detailing is very well portrayed. Soundstage width and height is expansive, especially when amped, and the Aurora sounds grand, yet with a very clean soundscape. Music never sounded compressed or claustrophobic. Imaging and layering is accurate, and technical junkies will be pleased to be able to locate instruments easily in the headspace.
Unlike other very technical sets, the Aurora doesn't sound sterile and maintains a decent note weight. However, where the Aurora loses some marks in my book, is in its
timbral accuracy. In the upper frequencies, there is a slight hollowness to notes, especially for acoustic instruments like brasses and woodwinds. Vocals have a nasal twang too - this is a bit more prominent in female vocals.
COMPARISONS
Due to its very specialized driver configuration, I do not have any like-for-like IEMs with this setup in MidFI territory. Nevertheless, the Aurora will be compared against some other benchmark MidFI products.
Moondrop Variations
The Variations is a Harman measurebator's gold-standard. The Variations has a prominent mid-bass scoop out, so it sounds much thinner and anemic than the Aurora in this region. The Aurora is a bit brighter in the treble.
The Variations is slightly weaker in micro-detailing and imaging, but has a bit more natural timbre and a slightly bigger soundstage and better layering.
I would consider them sidegrades at the MidFI segment. The Variations is about $120 USD more expensive though, and there are widespread reports of QC issues dogging this IEM (my Variations faceplate dropped out spontaneously without trauma, for example LOL).
Letshuoer EJ07M
The EJ07M is also U-shaped, but has a bit of a darker treble, and a thinner lower midrange.
The EJ07M has a hair better imaging, but has weaker instrument separation, soundstage and micro-detailing. In fact, the EJ07M's soundstage is notably small and claustrophobic on doing A/B comparisons back-to-back with the Aurora.
The EJ07M suffers from horrendous driver flex, which may be a deal-breaker for some.
CONCLUSIONS
For folks wanting a balanced U-shaped pair with stellar technical prowess, the 7Hz Aurora is one to mull over. Technical chops are a highlight, in particular for imaging, soundstage and micro-detailing. Bass is very fast and clean, though not at bona fide basshead amounts, so it is a case of quality over quantity. The transparent midrange allows instruments and vocals to breathe, with good treble sparkle noted.
In terms of non-sonic tangibles, the Aurora is generously accessorized, with a modular cable for myriad source matching. Isolation is above average with relatively fuss-free drivability. While the shells are on the larger side, comfort is surprisingly decent in view of the lightweight shells.
For the ardent timbre-freaks amongst us, a negative would be a metallic timbre noted in the upper frequencies for female vocals and acoustic instruments. By and large, this is a bit more prominent for acoustic genres, and may be mitigated somewhat with tip choice or perhaps source pairing.
All things considered, the 7Hz Aurora belongs in the MidFI conversation, doing most departments well.