64 Audio U4S VS Symphonium Audio Helios SE

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The 64 Audio U4s hits a compelling sweet spot: a 1DD+3BA hybrid around $1,100 that echoes the lush, bass-tilted character of the Nio while fixing key drawbacks. Packaging and accessories feel improved, with multiple tip options and the included M12 APEX module; APEX not only tailors bass but also relieves pressure for long sessions. Fit follows 64 Audio’s comfortable triangular shell; the vented DD asks for a slightly shallower insert than the all-BA models. Sonically, expect a sub-bass-oriented shelf and a treble profile that’s more lively and “zingy” than the Nio, with extra energy around the upper treble. The big caveat is 64 Audio’s muted 2–4 kHz region, which can set soprano vocals a step back on the stage.

Against the brand’s full-BA staples (think U12t/U6t), the U4s trades some pinpoint imaging and coherency for unmistakable DD slam and tactile “air pushing.” Extension at both ends is excellent, with upper-treble energy that makes micro-detail and reverb trails pop. It’s not the clean, conventional neutrality of something like a Monarch-style tuning; rather, it’s a deliberate, colored signature that delivers fun plus technical chops. Crucially, it fills a missing niche at its price and, in many respects, outperforms the pricier Nio, making the U4s a standout recommendation for listeners who want bass authority, sparkle, and engaging dynamics without going all-in on the flagship tier.

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Symphonium Audio’s collaboration with Elise Audio turns the original Helios into a more wearable Helios SE without rewriting its sonics. The shell is smaller, cleaner-looking, and finished in teal, moving from “bulky and awkward” to a still medium-large but more secure fit. It remains unvented, so insertion technique matters, and fit security is improved rather than perfect. Accessories include a metal puck case, cleaning tool, and even a per-unit frequency response slip; the thin stock cable behaves well (4.4 mm on the loaner, 2-pin without earhooks). Power needs are modestly higher than average for an IEM but nowhere near full-size headphones. Only 50 units are being made at roughly $1,200.

The tuning mirrors the OG: a lean, bright-neutral balance with a midrange-forward center, very extended treble, and a sub-bass boost atop lean mid-bass/lower mids. Vocals pop with clarity and texture, and the treble is unusually incisive yet smooth, contributing to a stage that’s wide for the price. Despite using only four balanced armatures, sub-bass notes hit with convincing physicality—surprisingly close to a DD—when the track has true low-end content. The flip side: kick-drum-centric or classic-rock mixes can feel dry, the stage depth varies with bass content, and ride cymbals trade some metallic “ping” for a slightly swishy decay.

Versus peers, 64 Audio’s U4s reads as bassy-neutral with thicker mids and the most inherently tactile bass (it’s a DD, after all), while 7th Acoustics’ Supernova sits closer to neutral with fuller lower mids, sharper imaging, and a vented shell that locks in securely. Helios SE’s value is crystal-clear: keep the Helios’ stellar treble performance and wide headstage, fix the ergonomics, and leave the core tonality intact. It’s a set to respect more than love for those craving warmth, but for enthusiasts chasing clean, airy resolution and vocal focus, it’s a confident 4/5.

Youtube Video Summary

The 64 Audio U4s hits a compelling sweet spot: a 1DD+3BA hybrid around $1,100 that echoes the lush, bass-tilted character of the Nio while fixing key drawbacks. Packaging and accessories feel improved, with multiple tip options and the included M12 APEX module; APEX not only tailors bass but also relieves pressure for long sessions. Fit follows 64 Audio’s comfortable triangular shell; the vented DD asks for a slightly shallower insert than the all-BA models. Sonically, expect a sub-bass-oriented shelf and a treble profile that’s more lively and “zingy” than the Nio, with extra energy around the upper treble. The big caveat is 64 Audio’s muted 2–4 kHz region, which can set soprano vocals a step back on the stage.

Against the brand’s full-BA staples (think U12t/U6t), the U4s trades some pinpoint imaging and coherency for unmistakable DD slam and tactile “air pushing.” Extension at both ends is excellent, with upper-treble energy that makes micro-detail and reverb trails pop. It’s not the clean, conventional neutrality of something like a Monarch-style tuning; rather, it’s a deliberate, colored signature that delivers fun plus technical chops. Crucially, it fills a missing niche at its price and, in many respects, outperforms the pricier Nio, making the U4s a standout recommendation for listeners who want bass authority, sparkle, and engaging dynamics without going all-in on the flagship tier.

Youtube Video Summary

Limited to 50 units and co-signed with Elise Audio, Helios SE shows up as a 4BA oddball with a vibe: ultra-relaxed, non-aggressive, almost like every track sits one gain click lower than expected. Vocals sit nicely centered, instruments hang back, and stage/separation can flip between muted and “whoa” micro-split moments. Tip rolling swings the personality hard—silicons keep it chill, foam-style tips shove vocals forward and magnify the weirdness; think “interesting” more than “reference.” It’s an experience-first tuning that doesn’t try to punch for attention and can feel almost too polite on energetic songs.

Build is simple, soft cable, occasional twist mismatch, and some units in 3.5 mm that don’t scream “kilobuck.” The pitch here is rarity and flavor: graph glued to the box means nothing about how it actually feels—this is human-ear stuff, not squiggle worship. As a collection piece for lovers of unusual BA staging and “just chill” listening, it charms; as a $1k+ value play, not so much. The verdict: likeable around $500–$600 on novelty and tuning alone, but at four-figure pricing it’s more “own something rare and weird” than a slam-dunk daily driver.