64 Audio Nio VS 64 Audio U4S

Youtube Video Summary

The 64 Audio Nio enters as the most affordable set in this lineup at $1,700, a hybrid with 1DD + 8BA and swappable apex modules. Its core tonality is warm and a touch laid-back, with the M15 module pushing bass toward “too much of a good thing”—thick, soupy, and less resolving. Swapping to the M10 cleans things up: bass settles closer to neutral, top-end clarity improves, and the presentation feels more balanced overall. Detail is respectable rather than showy, and while the Nio can be bassy, it doesn’t deliver the most controlled low end when boosted. The standout trait here is timbre—the most natural-sounding of the group, especially with M10 installed.

Used as a daily driver, Nio with M10 suits listeners who want a smooth, natural tonality without treble bite; with M15, it veers into warm-thick territory at the cost of separation and perceived detail. Against 64 Audio’s own stable, it doesn’t reach the U12t’s BA bass quality or the Trio’s stage depth, but it offers an easygoing, organic listen that some will prefer on timbre alone. Verdict: 4/5 with the M10 module; drop to 3/5 on the M15 due to excessive bass and haze.

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

The 64 Audio Nio is a hybrid with 1DD + 8BA that leans into a richer, warmer presentation, trading ultimate microdetail for slam and engagement. Build and comfort are solid with a classy case upgrade; fit can vary, but tip selection helps. Technicals are mixed: imaging and separation are clean, staging is a bit intimate, and treble resolution is good via the TIA driver without sounding sharp.

The headline feature is the swappable apex modules. M15/M20 push the Nio into basshead territory—big sub-bass, head-nodding punch—while MX reins in the low end for a more balanced tonality that suits acoustic, jazz, and classical. Treble is well-extended yet relaxed; with the right tips, the 5 kHz energy avoids harshness, keeping the overall tuning smooth and non-fatiguing.

Against peers, the Nio’s strengths are its dynamics and configurable bass; its weaknesses are detail retrieval and stage size versus benchmarks like the 64 Audio U12t. Listeners chasing maximum clarity and air may prefer U12t, while those wanting hybrid physicality and tunable low-end will find strong value here. Verdict: choose M15/M20 for guilty-pleasure thump, choose MX for balance—the Nio remains a versatile, engaging high-end option.

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.