Seas Custom 6-1/2″ L18RNX/P based Prestige 4Ω Woofers, PAIR, NEW

$ 238.00 $ 99.00 (CAD)

NEW Seas Prestige 6.5″ Custom Woofers

Based on L18RNX/P platform and made in Norway. Sold in Pairs.

Designed for extended low frequency applications. Use four in a high end tower / floor standing cabinet or a single in a bookshelf cabinet!

From Seas:

This custom 6.5” High Fidelity woofer with an injection moulded metal chassis, is intended for sealed, bass reflex and transmission line designs.

Stiff, yet light black anodized aluminum cone and low loss rubber surround show no sign of the familiar 500-1500 Hz cone edge resonance and distortion associated with soft cones.

Large magnet system gives good transient response, and the bumped back plate together with the very long, and copper voice coil allow for extreme coil excursion with low distortion.

Extremely stiff and stable injection moulded metal basket, keeps the critical components in perfect alignment.

Large windows in the basket both above and below the spider reduce sound reflection, air flow noise and cavity resonance to a minimum.

In stock



  • Black Aluminum Cone and Dust Cap
  • Low Loss Surround
  • Power Handling: 100W Long Term, 250W Short Term (both as per IEC 268-5)
  • Basket Outside Diameter = 176.0 mm
  • Xmax = 6.0mm (12.0mm peak to peak)

 Voice Coil

  • 39mm diameter
  • 2-layer copper wire
  • 4 Ω nominal impedance
  • Aluminum Former
  • Overhung Design

Thiel/Small Parameters

Free Air Resonance, Fo 29 Hz
Moving Mass, Mms 22.18 g
Force Factor, BL 5.4 N/A
Impedance at Fo, Zo 31 Ω
Voice Coil DC resistance, Rdc 3.23 Ω
Effective Area, S 136 cm^2
Mech. Resonance, Rmec 1.04 Ns/m
Qms 3.9
Qes 0.45
Qts 0.41
VAS 35.2 liters
CMS 1.36 mm/N

Suggested Enclosures


Suggested cabinet volumes are between 7 and 15L. The latter yields a Butterworth alignment with a bass system resonance of 50Hz and a frequency response that is -3dB at 50Hz.


Suggested cabinet volumes are between 10 and 25L. The latter yields a Butterworth alignment when tuned to 29Hz with a 2″ ID x 10″ port.  The frequency response of this alignment is -3dB at 30Hz.


Measurements and Example Crossover

Our Custom Seas L18RNX/P woofer was installed in a sealed enclosure and a passive crossover was designed for an acoustic 2nd order LR low pass transfer function with a crossover frequency of 2KHz. This is a great transducer for a 2 or 3 way bookshelf or tower speaker crossed over to a midrange from 100 to 750Hz or a tweeter at 2 to 3KHz.


Frequency Response of a custom Seas L18RNX in a sealed cabinet with and without crossover.Frequency response of our Custom Seas L18RNX/P woofer a in sealed cabinet, with and without passive crossover (schematic below). Calibrated mic at 1M, 2.83V.



Schematic Diagram of a 2nd order LR low pass transfer function with a crossover frequency of 2KHz.

Additional information

Weight 8 lbs
Dimensions 8 × 8 × 8 in