Seas L12RCY-P
fullrange · EBP 152 → suits a ported box · nominal (full) — Seas datasheet (https://www.seas.no/images/stories/prestige/pdfdatasheet/h1207_l12rcy_p_datasheet.pdf)
Thiele/Small parameters
| Fs (resonance) | 50 Hz |
| Qts | 0.29 |
| Qes / Qms | 0.33 / 2.34 |
| Vas | 5.0 L |
| Re / nominal Z | 5.5 Ω / 8 Ω |
| Xmax | — |
| Sensitivity | 84.6 dB (1 W/1 m, calc); 85.5 dB (2.83 V/1 m, mfr) |
| Power handling | 70 W |
Published (nominal) values, params full — verify by measurement (DATS/REW) before building.
Datasheet (PDF) ↗ — manufacturer-hosted
Recommended enclosures
| Sealed (Qtc 0.707) — Vb | 1.0 L |
| Sealed — Fc / F3 | 121.9 / 121.9 Hz |
| Ported (suggested) — Vb | 1.7 L |
| Ported — Fb / F3 | 70.1 / 79.6 Hz |
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About this driver
The Seas L12RCY-P is a 4″ fullrange with a free-air resonance of 50 Hz and a total Q (Qts) of 0.29. Its efficiency-bandwidth product (EBP) of 152 points toward a ported alignment. In a 1.0 L sealed box it reaches an F3 of 121.9 Hz (Qtc 0.707); a suggested 1.7 L box tuned to 70.1 Hz extends to about 79.6 Hz. See the sealed vs ported guide for how to choose.
Recommended partners
modeled estimateThe tweeters below pair well with the Seas L12RCY-P 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.
- Seas 27TBFC/G H1212-06Good match· 92/100
Suggested crossover 2.06 kHz (4th-order, Linkwitz-Riley)
Build this pair → - SB Acoustics SB29RDC-C000-4Good match· 92/100
Suggested crossover 2.06 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Dayton Audio RS28F-4Good match· 92/100
Suggested crossover 2.06 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Dayton Audio EC30-4Good match· 92/100
Suggested crossover 2.06 kHz (4th-order, Linkwitz-Riley)
Build this pair → - SB Acoustics SATORI TW29BGood match· 92/100
Suggested crossover 2.06 kHz (4th-order, Linkwitz-Riley)
Build this pair → - SB Acoustics SATORI TW29B-BGood match· 92/100
Suggested crossover 2.06 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.