Overview

The Yamaha NS-B750 is a 2-way bass-reflex bookshelf speaker with a 13 cm Advanced PMD cone woofer and 3 cm aluminum dome tweeter crossed at 4 kHz. It was designed to deliver “live-sounding” reproduction, with a trapezoidal cabinet to reduce standing waves and a piano-black finish to match Yamaha’s grand pianos. Rated input is 30 W (max 120 W). [2][3]

Scientific Validity

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No credible third-party anechoic measurements for the NS-B750 could be found. Manufacturer specifications list 60 Hz–50 kHz frequency response, 87 dB sensitivity, 6 Ω nominal impedance, and 4 kHz crossover. These figures set expectations (notably limited bass below ~60 Hz), but do not substitute for controlled FR/DI/THD data. This score is therefore the baseline for unmeasured products, pending independent data. [2][3]

Technology Level

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Advanced PMD (PMP) woofer material and a conventional aluminum dome tweeter are competent 2010s-era choices. The cabinet geometry to mitigate standing waves is sensible. However, there is no evidence of distinctive advances (e.g., controlled directivity waveguides or demonstrably superior linearity). Overall, this reflects mainstream engineering rather than modern state-of-the-art. [2][3]

Cost-Performance

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Review target price (denominator): 1,040 USD, derived from Yamaha Australia’s official RRP of 1,599 AUD for the NS-B750 at the time of access (converted as of the review date). [1]

Cheapest equal-or-better comparator (numerator): Emotiva Airmotiv B1+ at 229 USD per pair. Equal-or-better basis: 2-way passive bookshelf with third-party Klippel NFS data showing flatness ±2.1 dB (300 Hz–5 kHz) and LFX ≈55 Hz, indicating at least comparable bandwidth and objectively superior on-axis tonality linearity to a catalog-only NS-B750. (Provisional equivalence due to lack of NS-B750 third-party data.) [3][4][6]

Calculation (policy-required form): 229 USD ÷ 1,040 USD = 0.22 → 0.2 (rounded to one decimal).

Note: ELAC Debut 2.0 B5.2 (269 USD) remains a relevant option but shows a documented +3 dB step around 1.5 kHz; it is not the cheapest equal-or-better comparator and thus not used for CP scoring. [5]

Reliability & Support

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The NS-B750 is discontinued; Yamaha Australia lists the model as such and provides the historical RRP. Yamaha’s US home-audio warranty terms for speakers typically span two years (region and model dependent). Discontinued status and region-specific policies reduce support prospects relative to current models, though the passive design itself has few failure points. [1][7]

Rationality of Design Philosophy

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As a passive 2-way with sensible cabinet geometry, the NS-B750’s direction is broadly rational and avoids pseudo-scientific claims. However, Yamaha provides no modern, transparent measurements, and there is no controlled-directivity implementation. The piano-black finish likely consumes cost without measurable fidelity gains, and the overall approach is conservative rather than innovation-led. Net result: slightly below average rationality.

Advice

If you specifically want the NS-B750 for its finish or brand, plan on subwoofer support to cover content below ~60 Hz (per manufacturer spec). Otherwise, objectively measured, lower-cost options like the Emotiva Airmotiv B1+ (229 USD) deliver better value. The ELAC DB 2.0 B5.2 (269 USD) is also viable but benefits from EQ near 1–2 kHz due to its measured step. [3][4][5]

References

[1] Yamaha Australia. “NS-B750 — Discontinued, RRP 1,599 AUD.” Accessed 2025-08-29. https://au.yamaha.com/en/products/audio_visual/speakers/ns-b750/index.html
[2] Yamaha Europe. “NS-B750 — Specs.” Accessed 2025-08-29. https://europe.yamaha.com/en/audio/home-audio/products/speakers/ns-b750/specs.html
[3] Spinorama.org. “Measurements for Emotiva Airmotiv B1+ (Erin’s Audio Corner; Klippel NFS) — flatness ±2.1 dB, LFX ≈55 Hz.” Accessed 2025-08-29. https://www.spinorama.org/speakers/Emotiva%20Airmotiv%20B1%2B/ErinsAudioCorner/index_eac.html
[4] Emotiva (official). “Airmotiv B1+ — Bookshelf Loudspeaker — 229 USD/pair.” Accessed 2025-08-29. https://emotiva.com/pages/airmotiv-old
[5] Erin’s Audio Corner. “ELAC Debut 2.0 B5.2 — Klippel NFS; +3 dB step ≈1.5 kHz.” Accessed 2025-08-29. https://www.erinsaudiocorner.com/loudspeakers/elac_db52/
[6] Audio Science Review. “Emotiva Airmotiv B1+ — Review & Measurements (Klippel NFS).” Accessed 2025-08-29. https://www.audiosciencereview.com/forum/index.php?threads/emotiva-airmotiv-b1-review-bookshelf-speaker.22366/
[7] Yamaha (US) via Parts Express. “Yamaha Home Audio Manufacturer Warranty — 2 years (home audio).” Accessed 2025-08-29. https://www.parts-express.com/pedocs/warranty/yamaha-home-audio-manufacturer-warranty.pdf

(2025.8.30)