Note that this is a discontinued product. You may want to visit the brand's page here to browse their newer products.
What reviewers think
Bloggers and YouTubers have tried this product—so we've summarized their strongest opinions below. Links to full reviews follow.
Product Strengths
- Excellent bass and treble response.
- Impressive dynamics and imaging.
- Has excellent treble extension.
- The Helios delivers an immensely deep-reaching sub-bass, accompanied by exceptionally clean articulate treble, with no overdone mid-bass to muddy things up.
Product Considerations
- Large angular shell that may be hard to fit.
- Needs a reasonably powerful source, because many dongles will not be able to run these.
- Midrange is somewhat mixed and quite pushed back.
- Some found the stock cable annoying to deal with.
- There is a lack of mid-bass.
Comparisons (according to reviewers)
- Vs Campfire Audio Andromeda 2020: Helios has a leaner sound and demands attention, sporting aggressive dynamics, sharper resolution, and BA bass that actually slams.
- Vs Hidition Viento-B: One can consider the Helios a Viento-B on steroids with more bass, a more balanced midrange, and a more linear, extended treble response.
- Vs Moondrop S8: The Helios clearly pulls ahead in its impactful dynamics and standout BA bass.
- Vs Sony IER-M9: The Helios has far better dynamics and a smoother, more airy treble response.
- Vs Thieaudio Monarch: The Helios has more treble extension and presence in those final octaves, and for technical performance outdoes the Monarch all around, particularly in the staging and imaging presentation.
- Vs Unique Melody MEST/MK2: The Helios doesn't make compromises, as it sports comparable resolution to the OG MEST and outclasses both IEMs in the dynamics department, and the Helios' treble is a step ahead of the ESTs being used in the MEST IEMs.
Takeaway: The Symphonium Helios is worth consideration for those seeking high-quality sound with great bass and clear highs. It is designed to sound good with diverse musical genres, so listeners can enjoy what they are hearing.
All
Helios - Technical Reference
reviews

Manufacturer details
- Driver Crossover: TrueX™ Custom 3-Way Crossover
- Frequency Response: 12 Hz – 21 kHz ±3 dB
- Sensitivity: 111 dB / Vrms @ 1 kHz
- Impedance: 9.7 Ω @ 1 kHz
- Socket: Spring-Loaded 0.78 mm 2-Pin
- Cable: 26 AWG Pure OCC Copper Litz (Nightjar Acoustics)
- Cable Impedance: 0.18 Ω (3.5 mm) / 0.17 Ω (4.4 mm) @ 1 kHz
- Warranty: 1-Year Limited
Brand highlights
Taking a step back to look at reviewers' thoughts of the brand's entire lineup—not just this product—what stands out most is the following:
- Symphonium differentiates itself by crafting IEMs with low driver counts, yet achieving sonic performance that often surpasses expectations for such configurations.
- The brand is known for its close collaboration with the audiophile community, incorporating feedback and insights from reviewers and enthusiasts into product development.
Select products
Meteor
- Positioning: An entry-level IEM line designed for compactness and everyday use.
- Description: It offers a crisp sound in a small package with a unique mini driver that delivers clear performance. Compared to the other models, its tuning and build are best for smaller rooms and tighter budgets, lacking the extra processing or larger drivers found in the Titan or Helios.
Titan
- Positioning: A mid-range model focused on delivering enhanced bass performance.
- Description: It provides a strong bass response with a dedicated driver setup that brings forward deep low frequencies. Compared to the Meteor or Helios, its simpler design suits users looking for a big sound while still meeting daily listening needs.
Helios
- Positioning: A mid-to-high range option aimed at clean sub-bass clarity and balanced sound.
- Description: It stands out with a custom low-end section that offers clear, punchy bass and smoother transitions across frequencies. When compared to the Titan, which emphasizes extra bass, Helios offers a wider soundstage and clarity.
Crimson
- Positioning: A high-end model designed for richer tonal detail and refined sound.
- Description: It features a novel tuning method that balances bass and treble for a fuller sound and improved detail. In contrast to the Helios or Titan, its design provides a more sophisticated performance for users who need refined audio imaging and extra sonic detail.
Giant
- Positioning: A flagship model offering groundbreaking performance and build quality in the lineup.
- Description: It uses an innovative driver and tuning design that delivers superior detail and a wide dynamic range. Compared to Crimson or Helios, its advanced build and processing meet the needs of users with high technical and functionality standards.
Our take on the brand
Look inside the brand
Our interview with the brand
What are two key technological innovations or strong opinions that differ you from other brands?
What's your approach to customer support?
What are your favorite tracks for showcasing the strength of your products?
What other products pair best with yours?
Used
Symphonium
What if you spend more?
Our summary
Product Strengths
- Beautifully balanced tonal quality
- Excellent and innovative shell design
- Unique unboxing and premium accessories
- Comfortable fit despite the larger shells
- Wide stereo separation
Product Considerations
- Treble might seem too controlled for some
- The sound is source dependent
- More mid-treble and air up top, lesser fullness in lower-midrange, and less of the mid-bass boost would be ideal
Comparisons (according to reviewers)
- Compared to 64 Audio’s Fourte and the Vision Ears Phonix, the Enigma competes with them in the summit-fi range
- Compared to Softears Twilight, the bass is tighter and more focused, with better detail, also the Enigma has a more precise and layered soundstage
- Compared to Elysian Annihilator, the Enigma trades the sharp precision of the Annihilator for a smoother and more forgiving presentation
- Compared to Empire Ears Odin, the Enigma is easier and more laid back to listen to, whereas the Odin grabs attention with its bold dynamics
- Compared to Lime Ears Anima, the Enigma feels more refined in comparison, excelling in accurate ear gain/upper-midrange, which results in it sounding more linear and natural
- Compared to Kinera Loki Emerald, the Enigma outshines the Loki in mids, offering a more natural and emotive presentation
Takeaway: The Softears Enigma is a well-balanced high-end IEM, with craftsmanship and attention to detail evident in its distinctive design and thoughtful packaging. If one favors a sound that leans toward musicality with a relaxed tuning, the Enigma is sure to please.
Video review
Our take on the brand
Product Strengths
- Custom, personalized fit due to custom molding, offering comfort and secure fit
- Excellent acoustic isolation, effectively blocking out external noise
- High sensitivity, making them easy to drive with various sources
- Astonishing sound with a high level of detail and clarity
- Durable build quality
Product Considerations
- High price
- Deep canal fit may not be comfortable for all users
- Requires external EQ tweaking to achieve optimal frequency response, as the out-of-the-box tuning may not be ideal
- The included case design can be unwieldy and annoying to open
- Ambient port plugs are small and can be easily lost
Comparisons (according to reviewers)
- Simpler implementation of drivers in the Sennheiser can yield better results
Takeaway: The Premier are a high-end custom in-ear monitor option with excellent sound reproduction, build quality, and personalized fit. For those who prioritize sound quality and custom fit, the Premier could be worth the investment for critical listening or professional use.
Video review
Our take on the brand
Our summary
Product Strengths
- Gorgeous IEM with a finish worthy of a top-of-the-line IEM, pictures not doing it justice
- Highly revealing, with incredible detail and microdynamics that deliver a vivid, lifelike reproduction of music
- Excellent speed and strong texture in the balanced armature based low-end
- Clean, detailed, and transparent mids with top-tier detail retrieval coupled with strong layering and separation
- Soundstage is wide and three-dimensional, with holographic imaging, giving a real sense of being on stage or in the studio with the performers
Product Considerations
- The IEM is on the larger side, so consider this if you've got smaller ears
- Ronin is bright and has energetic treble, which may not be preferred by those who like a warmer sound with bass emphasis
- Bass is more neutral, and it's not going to have the impact of a dynamic driver bass
- Treble can be somewhat unforgiving, highlighting unpleasant aspects of older or lower-quality recordings
- Some reviewers found the character of Ronin to be a little bright and sometimes bass-lite, and may need proper pairing to sound its best
Comparisons (according to reviewers)
- Vs Empire Ears Odin: Odin is more versatile, but Ronin's treble performance is at a higher level
- Vs 64 Audio Fourte Blanc: Fourte Blanc offers a more balanced sound overall, while Ronin leans towards a more technical, bright sound
- Vs Noble Viking Ragnar: Ragnar has more rumble and denser, deeper layers of bass, while Ronin has slightly higher resolution
- Vs Noble Sultan: Ronin has more details, while the Sultan is more weightier and warmer in representation
Takeaway: The Noble Ronin offers incredible detail, imaging, and resolution, delivering an immersive listening experience for those who appreciate a highly revealing sound. For those with a collection of high-resolution music who want to hear every nuance, the Ronin is an excellent choice.
Video review
Our take on the brand
Our summary
Product Strengths
- High-quality build and materials, with CNC-milled aluminum shell and Raffir composite faceplate, which gives a jewelry-like element
- Great imaging with a big soundstage, good instrument separation, and placement
- Excellent vocal imaging with a forward, intimate, and balanced vocal presence that avoids sibilance
- Deep bass extension with physical characteristics (bone conduction driver), and good texture across the entire range
Product Considerations
- Fit can be tricky due to the larger size, potentially problematic for those with smaller ears, but a deep penetration ensures a good seal with the right ear tip
- Can be source-sensitive, and might become muddy with warmer sources—more reference or incisive sources are recommended
- Bass bloom can overwhelm the mids on some recordings
Comparisons (according to reviewers)
- Vs Vision Ears VE10: The Onyx has a massive arena-like soundstage, while the VE10 feels more like a studio; the VE10 has stronger mids and more extended treble, but can be shouty
- Vs U12T: The Onyx has more focused and bodied vocals, and the bass provides better pressure and control, while the U12T has greater clarity
- Vs Aurora: The Onyx offers more precise and lively sound with better bass, and a more realistic vibration
Takeaway: The Noble Audio Onyx has a great build and delivers a unique, dark sound signature with a wide soundstage. With a good blend of bass, smooth highs, and clear vocals, the Onyx provides a great listening experience, especially for genres like rock and metal.
Video review
Our take on the brand
What competes at this price?
Our Summary
Product Strengths
- Ergonomically comfortable for long listening sessions, and has significantly improved from the earlier Helios model.
- The bass is exceptional in quality, it's tasteful, well-controlled and doesn't intrude into the mids or lower mids.
- The Crimson delivers above and beyond expectations if the fit and power requirements are met, demonstrating quality of drivers over quantity.
- Dynamics, soundstage, and resolution are at a flagship level, offering an immersive listening experience.
- The all BA configuration allows the bass to slam hard as some of the best dynamic driver IEMs out there.
Product Considerations
- The upper treble can be too bright and zingy, potentially causing listening fatigue, particularly on certain tracks and sources.
- The sealed, ventless design can create pressure buildup in the ear canals, leading to discomfort, especially during flights or long train rides.
- The Crimson requires a powerful source to perform at its best, and may sound bland if not adequately powered.
- The short nozzle and specific design may cause fit issues for some users, requiring experimentation with different ear tips for optimal fit and seal.
- The stock cable's ear hook is practically non-existent and not doing anyone any favors.
Comparisons (according to reviewers)
- Compared to the 64 Audio U12t, the Crimson is technically superior, particularly in bass and upper-midrange, but lacks venting for longer listening.
- Compared to the Elysian Diva, the Crimson has an edge in technical performance—particularly for a sense of sound stage.
- Compared to the Unique Melody MEST MKIII, the Crimson has much sharper sounding treble, and it has way more energy in the upper treble unlike the MKIII.
Takeaway: The Symphonium Crimson is an IEM that delivers exceptional sound quality and powerful bass despite having only 4 BA drivers, making it great for listeners that want to enjoy a highly detailed and immersive listening experience. For those seeking a unique and high-performing audio experience, the Crimson is worth considering.
Video review
Our take on the brand
Our Summary
Product Strengths
- Captures the sound of the original Svanar, with a balanced tuning emphasizing bass and treble while maintaining the mids
- Incredible imaging performance, offering a wide, well-rounded, three-dimensional soundstage with excellent positioning and separation—highly competitive, even compared to non-TWS IEMs under $1000
- Has an R2R DAC which permits unreachable technical performance
- Very light and comfortable
- Excellent connectivity and usability
Product Considerations
- LDAC connectivity issues with invasive intermittence and noise cutting
- ANC and Transparency mode aren’t very useful and lack dynamic, delivering leaner dynamic, less musicality
- Plastic build might not be most durable if dropped
- High-frequencies are quite sensible to the source, making it one of the least forgiving TWS
- Hiss is also present
Comparisons (according to reviewers)
- The Svanar Wireless is punchier, with better bass detail and imaging, and a wider soundstage, while the Final ZE8000 has a warmer, more neutral sound
- The Svanar Wireless has stronger imaging performance, a wider soundstage, and a better balance between separation and cohesion
- The Svanar Wireless is superior in technicalities and tonal balance, as well as timbre and tone naturalness, and ultimately musicality
- The Svanar Wireless' soundstage is taller and wider but not as deep, since clarity isn’t as sharp and clean, silence being more "noisy"
- The Svanar Wireless has better sound and performs better technically
- The Sony TWS has bloated bass that overwhelms everything else; in comparison, the soundstage and treble performance of the Svanar Wireless is miles ahead, presenting a much more detailed, natural, and sophisticated kind of sound
Takeaway: The Svanar Wireless sounds impressive for wireless earbuds, and it has great connectivity and features. For those seeking high-end wireless sound, these are worth considering.
Video review
Our take on the brand
Our Summary
Product Strengths
- Excellent reference monitor with heavy focus on resolution and detail
- Clean and articulate midrange presentation
- Bass is firm and wide, more focused on ultra lows
- Has an almost flat-impedance curve, enabling a consistent sound across sources with differing output impedance
- Very detailed, offers surgical precision, separates instruments into layers
- Offers great detail
Product Considerations
- Can be unforgiving of bad quality audio or sources
- Treble does not have much energy or sparkle
- Dainty stock cable and limited accessories
Comparisons (according to reviewers)
- Compared to Dunu Glacier, Dunu Glacier has a huge bass difference and more air
- Compared to the Elysian Diva, the RS-10 can beat the Diva in terms of technicalities, the Diva is an easier listen
- Compared to the Softears Volume, the tonality is very similar with a few differences, except the RS-10 is just much more detailed
- Compared to the Oriolus Percivali, vocal presentation from the RS10 is based on accuracy and linearity, the Percivali goes a step further in ornating the vocals with stronger richness and layering
Takeaway: The RS10 Reference is a supremely detailed and largely neutral monitor that is a good fit for studio monitoring. It emphasizes vocals and detail, highlighting all the nuances in your music.
Video review
Our take on the brand
Our Summary
Product Strengths
- Kadence aims to achieve a reference sound with the best possible details and balance.
- Technically very strong, with a neutral and uncolored sound.
- Excellent micro-detail.
- The mids have great transparency, resolution, and realistic timbre.
- The treble is transparent, detailed, and high-resolution, without being aggressive, thick, or thin.
Product Considerations
- Kadence is not a monitor to impress on first listen.
- The larger body for its housing may result in a fit that seems a bit stretched out and may not be the most comfortable IEM in its price range.
- It can slide down ears if proper eartips are not used.
- Listening to poor quality records can be underwhelming.
Comparisons (according to reviewers)
- Vs Sennheiser IE 900: Kadence's soundstage may initially seem underwhelming compared to the IE 900, but it provides transparency and clear stereo positioning.
Takeaway: The Kadence is a neutral IEM that offers accurate sound, high comfort, and durability, making it great for long listening sessions. It presents a spacious soundstage and a great deal of detail in the treble, midrange, and bass.
Video review
Our take on the brand
Our Summary
Product Strengths
- Thunderous lows with thick bass slam, detail, and texture are delivered.
- Wide, three-dimensional soundstage, with a strong, focused center image.
- Clarity in the midrange, with a bit of coloration that adds character, especially to male vocals.
- Treble presentation that's airy and sparkly, with the right amount of detail.
- Engaging, fun sound signature overall.
Product Considerations
- People with smaller ears might have a little difficulty getting the right fit because of the large shell.
- Discomfort can occur after extended wear for some users due to the shell's size or shape pressing against the ear.
- Some reviews say that the stock cable might be of lower quality than expected for the price range.
- The sound signature is V-shaped, which may not appeal to everyone.
- The timbre has a 'cool' characteristic, which might not be the most natural sound.
Comparisons (according to reviewers)
- Vs 64 Audio Volur, the Spartacus offers faster and more detailed bass, while the Volur has more natural bass, the Volur also has airier treble and clearer, more holographic imaging.
Takeaway: The Noble Audio Spartacus is an IEM with a fun and engaging sound that is great for people who love a lot of bass and big soundstages. It's fast, detailed, and technically impressive, making it a great choice for many music genres.
Video review
Our take on the brand
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