Overview

The 64 Audio Nio is a universal-fit hybrid IEM that combines one 9 mm dynamic driver with eight balanced armature drivers in a 4-way crossover. It incorporates the company’s patented tia (Tubeless In-Ear Audio) and apex pressure-relief modules (m20/m15/mX included), and lists at 1699 USD. Official specs state 6 Ω impedance and 105 dB/mW sensitivity. [1][5]

Scientific Validity

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Independent frequency-response (FR) measurements consistently show a strong low-frequency elevation with the m15/m20 modules, while the mX module reduces bass and shifts the overall tonality closer to neutral. Headphones.com’s IEC-711 clone measurement for Nio (m15) also notes ~1–2 dB channel mismatch in the mids/bass on the tested unit. These observations match Crinacle’s review commentary on the two “personalities” (m15/m20 vs. mX). Taken together, Nio offers an enjoyable, warm response but does not aim for strict neutrality or ±1 dB transparency across the band. [7][8]

Technology Level

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Nio implements 64 Audio’s tia open-BA architecture (direct-radiating, tubeless high driver) and the interchangeable apex modules that trade isolation for pressure relief and tuning options. These are real, testable mechanisms rather than cosmetic features, and the hybrid 1DD+8BA package with a 4-way crossover is an advanced build. Still, the overall tech stack is comparable to other high-end hybrids today rather than uniquely beyond them. [1][5]

Cost-Performance

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Basis — We must compare against the cheapest product that provides equivalent or better user-facing function and measured performance.

• Comparator selected: Etymotic ER2SE (wired IEM; passive isolation; neutral FR target; widely measured; same essential user function set). Its manufacturer-listed isolation is 35–42 dB, which is higher than Nio equipped with apex (mX ≈ −10 dB, m15 ≈ −15 dB, m20 ≈ −20 dB). Third-party FR measurements place ER2SE close to a diffuse-field/neutral target. Therefore, for core axes relevant to IEM fidelity (FR linearity; passive isolation), ER2SE qualifies as equivalent-or-better from the listener’s perspective. [2][3][4][9][10]

• Cheapest verified market price (ER2SE): 149.99 USD (official store; sale pricing excluded for CP).
  Nio price (denominator): 1699 USD.
  CP calculation: 149.99 USD ÷ 1699 USD = 0.0883 → 0.1 after rounding to one decimal place. [1][9]

(Notes: apex isolation figures are manufacturer-published per module; ER2SE’s isolation is manufacturer-published and repeatedly validated in practice by deep-insertion Etymotic designs. FR evidence for both models relies on third-party coupler measurements.) [2][3][4][7][8][10]

Reliability & Support

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A CNC-machined aluminum shell, detachable 0.78 mm 2-pin cable, and established brand history support durability. 64 Audio states a 2-year limited warranty on universal IEMs; service is handled via the company and authorized channels. Complex multi-driver architectures and swappable modules add potential failure points versus simpler designs, but overall support and construction are appropriate for a flagship product. [1][6]

Rationality of Design Philosophy

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The design prioritizes tangible mechanisms—apex (ear-pressure management) and tia (open BA/tubeless high)—backed by plausible acoustic reasoning. From a pure fidelity standpoint, the stock m15/m20 tunings favor bass quantity over strict transparency, while mX enables a more neutral option. The approach is technically rational, though pricing is not driven by measured transparency gains alone. [5][7][8]

Advice

Choose Nio if you specifically want a luxurious, bass-elevated presentation with excellent imaging and the ability to retune toward neutral using mX. If your priority is measurement-driven neutrality and maximum passive isolation per dollar, the ER2SE delivers those objectives at a tiny fraction of the price (and therefore defines Nio’s low CP score). If you like Nio’s ergonomics/feature set but want less bass by default, plan on using the mX module. [2][4][7][8][9][10]

References

[1] 64 Audio — “Nio” product page, specs & price. https://www.64audio.com/products/nio (accessed 2025-08-25).
[2] 64 Audio — “m20 apex module” (−20 dB isolation). https://www.64audio.com/products/m20-apex-module (accessed 2025-08-25).
[3] 64 Audio — “m15 apex module” (−15 dB isolation). https://www.64audio.com/products/m15-apex-module (accessed 2025-08-25).
[4] 64 Audio — High-Fidelity Earplugs page (module isolation overview incl. mX −10 dB). https://www.64audio.com/pages/high-fidelity-earplugs (accessed 2025-08-25).
[5] 64 Audio — “tia” technology page. https://www.64audio.com/pages/tia (accessed 2025-08-25).
[6] 64 Audio — Warranty page (2-year limited warranty incl. universal models). https://www.64audio.com/pages/warranty (accessed 2025-08-25).
[7] Headphones.com — “64 Audio Nio Review: The Triumph of Bass,” incl. IEC-711 FR & ~1–2 dB channel variance note. https://headphones.com/blogs/reviews/64-audio-nio-review-the-triumph-of-bass (accessed 2025-08-25).
[8] In-Ear Fidelity — “64 Audio Nio Review: The Real N8,” discussion of m15/m20 vs. mX tonality. https://crinacle.com/2020/11/24/64-audio-nio-review-the-real-n8/ (accessed 2025-08-25).
[9] Etymotic — ER2 series/ER2SE price listing (MSRP 149.99 USD; sale excluded for CP). https://etymotic.com/earphones/ (accessed 2025-08-25).
[10] In-Ear Fidelity — ER2SE FR graph page (711-type coupler). https://crinacle.com/graphs/iems/etymotic-er2se/ (accessed 2025-08-25).

(2025.8.25)