SB Acoustics SB20PFCR30-4

• Sensitivity (1W, 1m, infinite baffle) SPL1W 89.7dB

Thiele & Small parameters

• Resonance frequency (free air) fS 34Hz
• Mechanical quality factor QMS 2.78
• Electrical quality factor QES 0.37
• Total quality factor QTS 0.33

Large signal parameters

• Maximum linear excursion xmax 5.8mm
• Air volume displaced at xmax VD 124cm³
• Power handling P 50W
• Program power Pmax 100W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.4Ω
• Inductance (1kHz) LE 0.71mH
• VC Diameter 30.5mm
• Winding height HVC 16.5mm

Magnet

• Flux density B 1.2T
• Force factor Bl 6.6N/A
• Motor constant Bl/√RE 3.58N/√W
• Air gap height HAG 5mm
• Weight 0.54kg

Diaphragm

• Effective diameter 166mm
• Effective area SD 216cm²
• Moving mass MMS 22.4g
• Moving mass (without air load) MMD 20.1g
• Material Natural fibers (made in-house)

Suspensions

• Stiffness KMS 1N/mm
• Compliance CMS 1000µm/N
• Equivalent volume to the compliance VAS 66.2L
• Mechanical resistance RMS 1.7N·s/m
• Surround material Rubber

Dimensions

• Nominal diameter 8″
• 203mm
• Volume occupied by the driver (estimated) 0.57L
• Net weight 1.42kg
• Frame material Reinforced plastic