Overview

The FE208SS-HP is a 20 cm (8”) full-range unit featuring an HP (Hyperbolic Paraboloid) diaphragm with a cellulose-nanofiber/mica mixed coating layer, an external dual-ferrite motor with a copper cap and T-pole piece, and UDRT (Up-Down Roll Tangential) surround/spider. It launched as a limited release at ¥55,000 (incl. tax) per unit and is now discontinued. Key published data: 8 Ω, 94.5 dB (1 W/1 m), fs = 32 Hz, Qts = 0.17, Vas = 96.38 L, Mms = 15.1 g, Bl = 10.74 N/A, response fs–23 kHz. Uses Faston 205 gold-plated terminals and an aluminum die-cast frame.

Scientific Validity

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No independent lab set covering on/off-axis frequency response, distortion (THD/IMD), directivity, and large-signal linearity (e.g., Klippel LSI) has been published; thus the baseline stays at 0.5. The maker discloses full T/S (Re = 7.2 Ω, Le = 0.14 mH, fs 32 Hz, Qts 0.17, Vas 96.38 L, SPL 94.5 dB) and on/30°/60° curves, which helps transparency but does not substitute for third-party verification.

Key numbers vs. rival (excerpt)

Item	FE208SS-HP	Dayton PS220-8
Format	8″ full-range (HP cone)	8″ full-range
Nominal Z	8 Ω	8 Ω
Sensitivity	94.5 dB (1 W/1 m)	96.5 dB (2.83 V/1 m)
Band (spec)	fs–23 kHz	40–25 kHz
fs	32 Hz	46.4 Hz (meas.)
Qts	0.17	0.38 (meas.)
Bl	10.74 N/A	7.47 N/A (Klippel)
Xmax	— (n/a)	4.8 mm (Klippel)
Public measurements	Maker T/S & on/off-axis FR	FRD/ZMA + Klippel LSI

Technology Level

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Materials/process and motor details (nanofiber-mixed coating, copper-capped dual-ferrite motor, T-pole flux shaping), UDRT geometry, and dovetail-less direct leads (mass symmetry at 180°) constitute an advanced full-range implementation aimed at resonance dispersion and current-induced distortion reduction.

Cost-Performance

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Comparator (cheapest with equal-or-better functionality & published measurements): Dayton Audio PS220-8. Street price 163.98 USD. Publishes FRD/ZMA and Klippel LSI.
FE208SS-HP price ¥55,000. With a mid-market USD/JPY ≈ 147.5, ¥55,000 ≈ 373 USD.
CP ratio = 163.98 USD / 373 USD ≈ 0.44 → 0.4.
Sensitivity and HF extension favor PS220-8; FE208SS-HP’s lower fs (32 Hz) is a countervailing strength, but the lack of independent full measurement puts it at a value disadvantage.

Reliability & Support

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Fostex provides documentation and support, but limited-run and discontinued status introduces parts/availability risk. No extended-warranty/failure-rate data found. Physical build (gold-plated Faston, die-cast frame) is solid.

Rationality of Design Philosophy

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The design aligns with acoustic first principles: increase stiffness-to-mass, disperse modal resonances, and linearize the motor. However, premium pricing without independent verification tempers claims of technical supremacy.

Advice

If you value Japanese engineering craft and a limited-run concept, FE208SS-HP is attractive—but given discontinued status and the price gap versus PS220-8 (with robust published measurements), most builders should prioritize the latter unless collecting or aiming for specific horn alignments that exploit FE208SS-HP’s lower fs.

References (URLs)

1. Fostex FE208SS-HP product page (specs/status)
   https://www.fostex.jp/en/products/fe208ss-hp/
2. Fostex FE208SS-HP Specification & Application Sheet (PDF)
   https://www.fostex.jp/wp/wp-content/uploads/FE208SS-HP_specification_application_sheet.pdf
3. Fostex News Release (¥55,000 incl. tax, PDF)
   https://www.fostex.jp/wp/wp-content/uploads/Fostex_FE208SS-HP_News_Release.pdf
4. Parts Express – Dayton Audio PS220-8 (price/specs/resources)
   https://www.parts-express.com/Dayton-Audio-PS220-8-8-Point-Source-Full-Range-Neo-Driver-295-346
5. Parts Express – PS220-8 Klippel Test Results (PDF)
   https://www.parts-express.com/pedocs/tech-docs/295-346-dayton-audio-ps220-8-klippel-test-results.pdf
6. XE – Historical Rates Tables (mid-market reference, USD/JPY)
   https://www.xe.com/currencytables/?from=JPY

(2025.8.14)