Scan-Speak 18W/8531G00
midwoofer · EBP 72 → suits either box · nominal (partial) — Scan-Speak datasheet (manufacturer)
Thiele/Small parameters
| Fs (resonance) | 28 Hz |
| Qts | 0.36 |
| Qes / Qms | 0.39 / 5.1 |
| Vas | 58.2 L |
| Re / nominal Z | 5.8 Ω / 8 Ω |
| Xmax | 6.5 mm |
| Sensitivity | 87.0 dB (1 W/1 m, calc); 88 dB (2.83 V/1 m, mfr) |
| Power handling | 70 W |
Published (nominal) values, params partial — verify by measurement (DATS/REW) before building. datasheet
Recommended enclosures
| Sealed (Qtc 0.707) — Vb | 20.4 L |
| Sealed — Fc / F3 | 55.0 / 55.0 Hz |
| Ported (suggested) — Vb | 40.0 L |
| Ported — Fb / F3 | 31.5 / 32.3 Hz |
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About this driver
The Scan-Speak 18W/8531G00 is a 7″ midwoofer with a free-air resonance of 28 Hz and a total Q (Qts) of 0.36. Its efficiency-bandwidth product (EBP) of 72 points toward either alignment. In a 20.4 L sealed box it reaches an F3 of 55.0 Hz (Qtc 0.707); a suggested 40.0 L box tuned to 31.5 Hz extends to about 32.3 Hz. See the sealed vs ported guide for how to choose.
PUBLISHED T/S; independent (Zaph/HiFiCompass) Fs~30-33, Qts~0.41-0.50, Vas~41-49 L. Verify by measurement.
Recommended partners
modeled estimateThe tweeters below pair well with the Scan-Speak 18W/8531G00 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.
- Dayton Audio RS28F-4Good match· 88/100
Suggested crossover 1.19 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Seas 27TBFC/G H1212-06Good match· 88/100
Suggested crossover 1.19 kHz (4th-order, Linkwitz-Riley)
Build this pair → - SB Acoustics SB29RDC-C000-4Good match· 86/100
Suggested crossover 1.19 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Peerless by Tymphany D27TG35-06Good match· 77/100
Suggested crossover 1.37 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Dayton Audio ND25FA-4Poor match· 48/100
Suggested crossover 2.02 kHz (4th-order, Linkwitz-Riley)
Build this pair →
Modeled estimate from T/S + geometry — no measurements. The verdict is robust; it improves with measured FRD/ZMA data.