Sony IER-M9 VS Symphonium Helios SE

IEM Comparison: Expert & Community Scores Side-by-Side

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Sony IER-M9 and Symphonium Helios SE use 5BA and 4BA driver setups respectively. Sony IER-M9 costs $1,000 while Symphonium Helios SE costs $1,150. Symphonium Helios SE is $150 more expensive. Symphonium Helios SE holds a clear 0.6-point edge in reviewer scores (7.4 vs 8). Sony IER-M9 carries a user score of 7.5. Sony IER-M9 has better bass with a 0.5-point edge, Symphonium Helios SE has better treble with a 0.5-point edge, Symphonium Helios SE has significantly better dynamics with a 2-point edge and Symphonium Helios SE has better imaging with a 0.5-point edge.

Insights

Metric Sony IER-M9 Symphonium Helios SE
Bass 7.5 7
Mids 8 8
Treble 7.5 8
Details 8 8
Imaging 7 7.5
Dynamics 5 7
Tonality 7.5 8
Technicalities 7.6 8
Take these comparisons with a grain of salt—we don't have enough Symphonium Helios SE reviews saved yet to provide an unbiased result.

Sony IER-M9 Aggregated Review Score

Average Reviewer Scores

Audionotions Precogvision Tim Tuned Crin
Yifang

Average Reviewer Score:

7.4

Generally Favorable

Symphonium Helios SE Aggregated Review Score

Average Reviewer Scores

Precogvision
Jays Audio Nymz Yifang

Average Reviewer Score:

8

Very Positive

Reviews Comparison

Sony IER-M9 reviewed by Yifang

Yifang 8 Reviewer Score
S- Tuning
A+ Tech
check links for more info:

Yifang original ranking

Yifang Youtube Channel

Symphonium Helios SE reviewed by Yifang

Yifang 8 Reviewer Score
A+ Tuning
A+ Tech
check links for more info:

Yifang original ranking

Yifang Youtube Channel

Sony IER-M9 reviewed by Precogvision

Precogvision 7.4 Reviewer Score
A- Tuning
B+ Tech
Boring, but you won't find anything more well-rounded for the price. Exceptional timbre for a BA IEM.

Precogvision original ranking

Precogvision Youtube Channel
Bass: A- Mids: A+ Treble: A- Dynamics: C+ Details: A+ Imaging: A-

Symphonium Helios SE reviewed by Precogvision

Precogvision 7.4 Reviewer Score
A- Tuning
A- Tech
YouTube video thumbnail
See Helios but with more mid-treble and mid-bass.
Youtube Video Summary

Symphonium’s Helios arrives as a four-BA flagship with a spartan unboxing: a solid aluminum, waterproof “hockey-puck” case, multiple tip sets, and a standard 0.78 mm cable. Build is plain but substantial, and the shell is large with a wide nozzle—fit and comfort will be the biggest variable. The stock case’s rough threading and the cable’s lack of ear guides are minor gripes, but the overall presentation feels purposeful rather than flashy.

Tonally, Helios tracks Harman through the low mids, with a sub-bass-focused shelf and almost no mid-bass for maximum cleanliness—bass stays out of the mids and still slams impressively for BA. The midrange is clean and slightly lean (200 Hz dip, relaxed pinna gain) but well balanced. Treble is the showpiece: linear, extended, and airy to the edge of audibility, delivering uncommon “air” for the price. With Azla-style tips that air can verge on abrasive; swapping to the included silicone tips smooths the top end and improves coherence without dulling the sparkle.

Technicalities punch at the front of the kilobuck pack: resolution that hangs with class leaders, incisive imaging with uncanny “backwards” cues, and lively macro/micro-dynamics that give transients real snap. It may trail ultra-high-end sets by a hair in bass texture, but overall performance is compelling enough to edge out many peers. Verdict: an easy recommendation on sound alone, with the caveat to demo for fit—the shell size and nozzle girth will decide whether this brightest kilobuck star truly shines for you.

Bass: A- Mids: A+ Treble: A- Dynamics: A- Details: A+ Imaging: A-

Precogvision original ranking

Precogvision Youtube Channel

Sony IER-M9 (more reviews)

Sony IER-M9 reviewed by Audionotions

Audionotions 7.5 Reviewer Score
Nice note weight, very balanced, shockingly good at imaging held back by finicky fit and vacuum seal - fit issues can be resolved by changing tips though (for me the stock silicone LL tips eliminated fit issues for me but YMMV). At used prices today, it's a steal.

Audionotions original ranking

Website (Audionotions)

Sony IER-M9 reviewed by Tim Tuned

Tim Tuned 7 Reviewer Score
A- Tuning
A+ Tech
Just great accross the board, nothing to fault Not very special

Tim Tuned original ranking

Tim Tuned Youtube Channel
Bass: A+ Mids: A+ Treble: A+

Sony IER-M9 reviewed by Crin

Crin 7 Reviewer Score
A- Tuning
A Tech
Neutral tonality, highly coherent and decent detail pickup. The all-rounder of the IER lineup.

Crin original ranking

Crin Youtube Channel

Symphonium Helios SE (more reviews)

Symphonium Helios SE reviewed by Jays Audio

Jays Audio 8.5 Reviewer Score
S- Tuning
S- Tech
Best Treble around it's price. Super airy but still smooth. Bass-scoop isn't as bad as I thought, but those who want mid-bass - avoid it.

Jays Audio original ranking

Jays Audio Youtube Channel

Symphonium Helios SE reviewed by Nymz

Nymz 8.1 Reviewer Score
A+ Tuning
A+ Tech
Limited to 50 units. A huge improvement fit wise versus the original. Great TOTL all-rounder. Great sub, upper mids and treble. Mid-bass is an improvement but still not boosted. Great technical chops while fixing the sense of plasticness the original had.

Nymz original ranking

Nymz Website

Bass: A- Mids: A+ Treble: S Details: A+ Imaging: A+

Sony IER-M9 User Review Score

Average User Scores

Average User Score:

Based on 1 user reviews

7.5

Strongly Favorable

Symphonium Helios SE User Review Score

Average User Scores

Average User Score: n/a

Based on 0 user reviews

No user reviews yet. Be the first one who writes a review!

Sony IER-M9 Gaming Score

Gaming Score & Grade

  • The gaming score is prioritizing technical capabilities of the IEM (Separation, Layering, Soundstage) and good value.

Gaming Score

6.5

Gaming Grade

B+

Symphonium Helios SE Gaming Score

Gaming Score & Grade

  • The gaming score is prioritizing technical capabilities of the IEM (Separation, Layering, Soundstage) and good value.

Gaming Score

7

Gaming Grade

A-

Sony IER-M9 Scorings

Average Technical & Tuning Grades

Average Tunign Grade

A
  • Expect an inviting tonal blend that adapts well to genres while staying largely composed. It strikes a nice blend of warmth and clarity.

Average Technical Grade

A
  • Technical performance is solid, offering clear separation and consistent detail retrieval. There's enough space for instruments to breathe.
Bass A
It serves up confident rumble and texture while keeping the spectrum balanced. You can enjoy bass-heavy music without fatigue.
Mids A+
The midrange sounds refined and revealing, balancing clarity with emotional weight. Timbre accuracy rivals studio monitors.
Treble A
The treble is exquisitely tuned, combining crystal detail with relaxed delivery. Micro-details emerge effortlessly.
Dynamics C+
Expect solid impact overall, even if finer gradations feel a touch smoothed. Micro-details could still be sharper.
Details A+
No subtlety is too small; the presentation exposes it all with composure. Complex tracks remain crystal clear.
Imaging A-
Spatial cues respond immediately, reflecting every movement in the mix. Spatial cues respond instantly to the mix.
Gaming B+
Respectable environmental presentation favors atmosphere over precision. Detects obvious directional cues while conveying game world ambiance. Bad value-to-cost for gaming purpose - not recommended

Symphonium Helios SE Scorings

Average Technical & Tuning Grades

Average Tunign Grade

A+
  • Tuning feels well executed, keeping a natural flow across the spectrum. Switching genres feels seamless.

Average Technical Grade

A+
  • The balance of resolution and space feels assured, keeping complex passages coherent. Layering is convincing on most studio mixes.
Bass A-
It serves up confident rumble and texture while keeping the spectrum balanced. You can enjoy bass-heavy music without fatigue.
Mids A+
The midrange sounds refined and revealing, balancing clarity with emotional weight. Timbre accuracy rivals studio monitors.
Treble A+
Highs sound shimmering and endless, with exquisite smoothness and detail. Air and sparkle feel endless.
Dynamics A-
Dynamic performance is excellent, combining sharp transients with strong contrast. Transients snap with authority.
Details A+
Inner textures glow vividly yet never feel etched or artificial. It borders on studio-monitor transparency.
Imaging A
You can literally point to where sounds originate across the stage. You can point to where sounds originate.
Gaming A-
Good fundamental spatial awareness for most gaming scenarios. Handles basic positioning well but may lack nuance in complex situations. Bad value-to-cost for gaming purpose - not recommended

Sony IER-M9 User Reviews

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M Makavelian
7.5

Worth it at used prices for neutral warm all rounder.

Pros
Great all rounder tuning, imaging, comfort.
Cons
Bit lacking in engagement, bass typical of BA drivers.

Symphonium Helios SE User Reviews

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