All systems operational.



SB Acoustics SB12PFCR25-4-COAX 4" Coaxial Speaker

Notify me when this product is available:

SB Acoustics logo


The SB Acoustics SB12PFCR-4-COAX is a 2 way coaxial loudspeaker drive unit featuring a 4" paper composite cone midwoofer with a 1" centre mounted soft dome tweeter.

Crossover designs can be found within the SB Acoustics Technical Notes webpage.

The tweeter is available as a spare part:  SB14ST-C000-4 , it can be adapted to repair various other coaxial speakers that feature a 1" pole piece.

Key Features:

  • Proprietary cone material with natural fibers made in-house.
  • Soft low damping rubber surround for improved transient response.
  • Compact large surround dome tweeter.
  • Non-resonant long life lead wires
  • Optimized motor system
  • Vented reinforced polymer chassis

Basic parameters (woofer):

Resonant frequency (fs) 58 Hz Nominal impedance (Zn) 4 Ω
Mechanical  Q factor (Qms) 4.07 DC resistance (Re) 3.1 Ω
Electrical Q factor (Qes) 0.36
Max power handling 30 W
Total Q factor (Qts) 0.33
Sensitivity (2.83V/1m)
Equivalent volume (Vas) 4.8L Chassis diameter

Here's the full datasheet:

.pdf link