SB Acoustics SB20FRPC30-8

• Sensitivity (1W, 1m, infinite baffle) SPL1W 91.6dB

Thiele & Small parameters

• Resonance frequency (free air) fS 39.4Hz
• Mechanical quality factor QMS 10.10
• Electrical quality factor QES 0.47
• Total quality factor QTS 0.45

Large signal parameters

• Maximum linear excursion xmax 4.1mm
• Air volume displaced at xmax VD 89cm³
• Power handling P 40W
• Program power Pmax 80W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 6.0Ω
• Inductance (1kHz) LE 0.22mH
• VC Diameter 30.5mm
• Winding height HVC 13.2mm

Magnet

• Flux density B 1.2T
• Force factor Bl 7.15N/A
• Motor constant Bl/√RE 2.92N/√W
• Air gap height HAG 5mm
• Weight 0.54kg

Diaphragm

• Effective diameter 166mm
• Effective area SD 216cm²
• Moving mass MMS 16.3g
• Moving mass (without air load) MMD 14g
• Material Natural fibers (made in-house)

Suspensions

• Stiffness KMS 1N/mm
• Compliance CMS 1000µm/N
• Equivalent volume to the compliance VAS 66.3L
• Mechanical resistance RMS 0.4N·s/m
• Surround material Foam

Dimensions

• Nominal diameter 8″
• 203mm
• Volume occupied by the driver (estimated) 0.58L
• Net weight 1.43kg
• Frame material Reinforced plastic