Symphonium Helios and Fir Audio VxV are in-ear monitors. Symphonium Helios costs $1,100 while Fir Audio VxV costs $999. Symphonium Helios is $101 more expensive. Symphonium Helios holds a clear 0.8-point edge in reviewer scores (8 vs 7.2). Symphonium Helios has significantly better bass with a 1.5-point edge, Symphonium Helios has significantly better mids with a 1.9-point edge, Symphonium Helios has significantly better treble with a 3.6-point edge, Symphonium Helios has significantly better soundstage with a 2-point edge, Symphonium Helios has significantly better details with a 1.6-point edge and Symphonium Helios has significantly better imaging with a 1.3-point edge.
Insights
Metric | Symphonium Helios | Fir Audio VxV |
---|---|---|
Bass | 7 | 5.5 |
Mids | 7.9 | 6 |
Treble | 8.6 | 5 |
Details | 8.1 | 6.5 |
Soundstage | 8 | 6 |
Imaging | 7.8 | 6.5 |
Dynamics | 7.5 | 7.2 |
Tonality | 7.8 | 5.5 |
Technicalities | 7.8 | 6.3 |
Symphonium Helios Aggregated Review Score
Average Reviewer Scores
Average Reviewer Score:
8Strongly Favorable
Fir Audio VxV Aggregated Review Score
Average Reviewer Scores
Average Reviewer Score:
7.2Generally Favorable
Reviews Comparison
Symphonium Helios reviewed by Shuwa-T
Fir Audio VxV reviewed by Shuwa-T
Symphonium Helios reviewed by Head-Fi.org
Fir Audio VxV reviewed by Head-Fi.org
Symphonium Helios (more reviews)
Symphonium Helios reviewed by Z-Reviews
Youtube Video Summary
Positioned as a $1,100 4BA set with a proprietary “sub-woofer” armature, Helios promises consistency via FLAT (Filtered Linear Attenuation Tuning). In practice, the claimed impedance immunity proves fickle: desktop gear can skew the treble and dynamics, and tube amps are a no-go. Performance clicks on the right solid-state portable (e.g., a Violectric unit), where the presentation opens up with striking clarity, tactile microdetail, and pinpoint imaging. The stage doesn’t just spread left–right; there’s convincing presence—sounds pop in and around the head with tidy placement. Low end is tight and clean rather than head-rattling; it accommodates bass, it doesn’t chase it.
Ergonomics dampen the honeymoon. The shell is big and oddly shaped, the stock cable has poor ear retention, and the included tips feel thick and overdamp the voicing. Tip rolling (e.g., Xelastec, foam-hybrids, or Dunu SS) helps restore balance and bass grip, but fit remains fussy. Once settled, Helios delivers a smooth, near-tame signature that’s detailed without harshness—more refinement than fireworks. Verdict: a highly capable, clear and composed monitor for source- and tip-savvy listeners; brilliant when the chain is right, but the overall package—from fit to amp matching—can be annoying enough to test patience.
Z-Reviews Youtube Channel
Symphonium Helios reviewed by Yifang
Symphonium Helios reviewed by Smirk Audio
Symphonium Helios reviewed by Nymz
Symphonium Helios reviewed by Precogvision
Youtube Video Summary
Symphonium Helios hits the kilobuck arena with a 4-BA flagship co-developed with Subtonic, priced around $1,100. The unboxing is minimal: a waterproof, aluminum “hockey-puck” case (cool but gritty threading), assorted tips, and a standard 0.78 mm cable without ear guides. The shell is surprisingly large—reportedly to house bigger capacitors and wider tubing for the desired treble extension—and the wide nozzle plus stick-out fit will be the biggest hurdle for many ears. Comfort varies; demoing first is wise.
Sonically, Helios tracks Harman-ish through the lower mids, then diverges for a more relaxed ear-gain and a showpiece treble. Bass is sub-bass focused with near-zero mid-bass, staying impeccably clean of the mids; for BA, it slams impressively—competitive with U12t—though a touch light on texture. Mids read lean/clean (200 Hz dip), while the top end is remarkably linear with huge air; with AZLA SednaEarfit tips it can verge on abrasive, but the included silicone tips smooth things out to a class-leading treble at this price. Technicals are excellent: incisive imaging (even occasional “backwards” cues), strong macro & micro-dynamics, and lively transients; ultimate resolving edges still nod to sets like Annihilator and U12t. Taken as a whole, Helios stands as a top-tier kilobuck pick on sound quality—its fit is the make-or-break.
Precogvision Youtube Channel
Symphonium Helios reviewed by Crin
Symphonium Helios Details
Driver Configuration: 4BA
Tuning Type: Neutral with Bass Boost
Brand: Symphonium Top Symphonium IEMs
Price (Msrp): $1,100
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Fir Audio VxV Details
Driver Configuration: n/a
Tuning Type: n/a
Price (Msrp): $999
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Symphonium Helios User Review Score
Average User Scores
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Fir Audio VxV User Review Score
Average User Scores
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Symphonium Helios Gaming Score

Gaming Score & Grade
- The gaming score is prioritizing technical capabilities of the IEM (Separation, Layering, Soundstage) and good value.
Gaming Score
6.8Gaming Grade
B+Fir Audio VxV Gaming Score

Gaming Score & Grade
- The gaming score is prioritizing technical capabilities of the IEM (Separation, Layering, Soundstage) and good value.
Gaming Score
5.1Gaming Grade
C+Symphonium Helios Scorings
Average Technical & Tuning Grades
Average Tunign Grade
A- The response is even and composed, lending itself to effortless genre hopping. Voices sit comfortably in the mix.
Average Technical Grade
A- Technical performance is solid, offering clear separation and consistent detail retrieval. There's enough space for instruments to breathe.
Fir Audio VxV Scorings
Average Technical & Tuning Grades
Average Tunign Grade
B-- A mostly enjoyable signature keeps things listenable despite a handful of quirks. It handles most playlists without major complaints.
Average Technical Grade
B- Technical ability is serviceable, keeping basic detail intact across simpler tracks. It keeps up with acoustic tracks without much fuss.
Symphonium Helios User Reviews
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