Sine Design

Eminence ALPHA-8A

woofer · EBP 107 → suits a ported box · nominal (full) — Eminence datasheet (https://cdn.shopify.com/s/files/1/0270/8665/1462/files/Alpha_8A.pdf)

Thiele/Small parameters

Fs (resonance)73 Hz
Qts0.59
Qes / Qms0.68 / 4.6
Vas17.8 L
Re / nominal Z5.3 Ω / 8 Ω
Xmax3.2 mm
Sensitivity91.9 dB (1 W/1 m, calc); 94 dB (2.83 V/1 m, mfr)

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

Datasheet (PDF) ↗ — manufacturer-hosted

Recommended enclosures

Sealed (Qtc 0.707) — Vb40.9 L
Sealed — Fc / F387.5 / 87.5 Hz
Ported (suggested) — Vb62.5 L
Ported — Fb / F349.5 / 42.9 Hz

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About this driver

The Eminence ALPHA-8A is a 8″ woofer with a free-air resonance of 73 Hz and a total Q (Qts) of 0.59. Its efficiency-bandwidth product (EBP) of 107 points toward a ported alignment. In a 40.9 L sealed box it reaches an F3 of 87.5 Hz (Qtc 0.707); a suggested 62.5 L box tuned to 49.5 Hz extends to about 42.9 Hz. See the sealed vs ported guide for how to choose.

Recommended partners

modeled estimate

The tweeters below pair well with the Eminence ALPHA-8A 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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