Sine Design

GRS 8PF-8

woofer · EBP 41 → suits a sealed box · nominal (full) — GRS datasheet (https://www.parts-express.com/pedocs/specs/GRS%20Spec%20Sheets/292-408--grs-8pf-8-spec-sheet.pdf)

Thiele/Small parameters

Fs (resonance)50 Hz
Qts0.98
Qes / Qms1.22 / 4.94
Vas28.9 L
Re / nominal Z7.2 Ω / 8 Ω
Xmax3.0 mm
Sensitivity86.5 dB (1 W/1 m, calc); 87 dB (2.83 V/1 m, mfr)
Power handling100 W

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

Datasheet (PDF) ↗ — manufacturer-hosted

Recommended enclosures

Sealed (Qtc 0.707) — VbInfinity L
Sealed — Fc / F350.0 / 39.7 Hz
Ported (suggested) — Vb540.7 L
Ported — Fb / F320.2 / 31.8 Hz
Open in designer →Use my measured parameters →Buy at Parts Express →

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About this driver

The GRS 8PF-8 is a 8″ woofer with a free-air resonance of 50 Hz and a total Q (Qts) of 0.98. Its efficiency-bandwidth product (EBP) of 41 points toward a sealed alignment. In a Infinity L sealed box it reaches an F3 of 39.7 Hz (Qtc 0.707); a suggested 540.7 L box tuned to 20.2 Hz extends to about 31.8 Hz. See the sealed vs ported guide for how to choose.

Recommended partners

modeled estimate

The tweeters below pair well with the GRS 8PF-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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