Sine Design

Eminence ALPHA-4-8

tweeter · EBP 146 → suits a ported box · nominal (full) — Eminence datasheet (https://cdn.shopify.com/s/files/1/0270/8665/1462/files/Alpha_4_8.pdf)

Thiele/Small parameters

Fs (resonance)123 Hz
Qts0.75
Qes / Qms0.84 / 6.83
Vas2.0 L
Re / nominal Z6.73 Ω / —
Xmax2.6 mm
Sensitivity—

Published (nominal) values, params full — verify by measurement (DATS/REW) before building.

Datasheet (PDF) ↗ — manufacturer-hosted

Recommended enclosures

This is a tweeter; Thiele/Small box parameters are not used for enclosure design.

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About this driver

The Eminence ALPHA-4-8 is a 4″ tweeter with a free-air resonance of 123 Hz and a total Q (Qts) of 0.75. Its efficiency-bandwidth product (EBP) of 146 points toward a ported alignment. See the sealed vs ported guide for how to choose.

Recommended partners

modeled estimate

The woofers and midranges below pair well with the Eminence ALPHA-4-8 in a two-way design — each grade is a modeled estimate of the crossover match, with a suggested crossover point. Open any pair in the guided builder to design the crossover and total the parts.

Modeled estimate from T/S + geometry — no measurements. The verdict is robust; it improves with measured FRD/ZMA data.

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