Seas CA18RNX
woofer · EBP 95 → suits either box · nominal (full) — Seas datasheet (https://www.seas.no/images/stories/prestige/pdfdatasheet/H1215_CA18RNX_Datasheet.pdf)
Thiele/Small parameters
| Fs (resonance) | 35 Hz |
| Qts | 0.31 |
| Qes / Qms | 0.37 / 1.9 |
| Vas | 33.0 L |
| Re / nominal Z | 5.8 Ω / 8 Ω |
| Xmax | — |
| Sensitivity | 87.7 dB (1 W/1 m, calc); 88.5 dB (2.83 V/1 m, mfr) |
| Power handling | 80 W |
Published (nominal) values, params full — verify by measurement (DATS/REW) before building.
Datasheet (PDF) ↗ — manufacturer-hosted
Recommended enclosures
| Sealed (Qtc 0.707) — Vb | 7.9 L |
| Sealed — Fc / F3 | 79.8 / 79.8 Hz |
| Ported (suggested) — Vb | 13.8 L |
| Ported — Fb / F3 | 45.8 / 50.4 Hz |
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About this driver
The Seas CA18RNX is a 6.5″ woofer with a free-air resonance of 35 Hz and a total Q (Qts) of 0.31. Its efficiency-bandwidth product (EBP) of 95 points toward either alignment. In a 7.9 L sealed box it reaches an F3 of 79.8 Hz (Qtc 0.707); a suggested 13.8 L box tuned to 45.8 Hz extends to about 50.4 Hz. See the sealed vs ported guide for how to choose.
Recommended partners
modeled estimateThe tweeters below pair well with the Seas CA18RNX 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 M64F001Good match· 92/100
Suggested crossover 1.25 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Seas MR18REX-XFGood match· 92/100
Suggested crossover 1.25 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Seas T25CF002Good match· 92/100
Suggested crossover 1.25 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Seas T29CF002Good match· 92/100
Suggested crossover 1.25 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Tang Band 25-1983Good match· 92/100
Suggested crossover 1.25 kHz (4th-order, Linkwitz-Riley)
Build this pair → - Tang Band 50-1426SEGood match· 92/100
Suggested crossover 1.25 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.