SB Acoustics SB12NRX25-4

• Sensitivity (1W, 1m, infinite baffle) SPL1W 84.5dB

Thiele & Small parameters

• Resonance frequency (free air) fS 55Hz
• Mechanical quality factor QMS 3.20
• Electrical quality factor QES 0.46
• Total quality factor QTS 0.40

Large signal parameters

• Maximum linear excursion xmax 5mm
• Air volume displaced at xmax VD 25cm³
• Power handling P 30W
• Program power Pmax 60W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.1Ω
• Inductance (1kHz) LE 0.14mH
• VC Diameter 25.4mm
• Winding height HVC 15mm
• Winding material Copper Clad Aluminium
• Former material Glass Fiber

Magnet

• Flux density B 0.84T
• Force factor Bl 3.6N/A
• Motor constant Bl/√RE 2.04N/√W
• Air gap height HAG 5mm
• Weight 0.32kg

Diaphragm

• Effective diameter 80mm
• Effective area SD 50cm²
• Moving mass MMS 5.6g
• Moving mass (without air load) MMD 5.3g
• Material Norex

Suspensions

• Stiffness KMS 0.637N/mm
• Compliance CMS 1570µm/N
• Equivalent volume to the compliance VAS 5.6L
• Mechanical resistance RMS 0.6N·s/m
• Surround material Butyl rubber

Dimensions

• Nominal diameter 4″
• 102mm
• Volume occupied by the driver (estimated) 0.3L
• Net weight 0.76kg
• Frame material Cast aluminium