Precision Devices PD.8BM20

• Sensitivity (1W, 1m, infinite baffle) SPL1W 89.8dB
• Frequency response 50 - 4500Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 49Hz
• Mechanical quality factor QMS 7.28
• Electrical quality factor QES 0.42
• Total quality factor QTS 0.40

Large signal parameters

• Maximum linear excursion xmax 4.5mm
• Air volume displaced at xmax VD 102cm³
• Power handling P 200W
• Program power Pmax 400W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.9Ω
• Inductance (1kHz) LE 0.52mH
• VC Diameter 51mm
• Winding height HVC 13mm
• Winding material Copper
• Former material Glass Fibre

Magnet

• Flux density B 1.29T
• Force factor Bl 12.5N/A
• Motor constant Bl/√RE 5.16N/√W
• Air gap height HAG 6mm
• Material Ceramic

Diaphragm

• Effective diameter 170mm
• Effective area SD 227cm²
• Moving mass MMS 34.4g
• Moving mass (without air load) MMD 31.9g
• Material Paper

Suspensions

• Stiffness KMS 3.26N/mm
• Compliance CMS 306µm/N
• Equivalent volume to the compliance VAS 22.2L
• Mechanical resistance RMS 1.46N·s/m

Dimensions

• Nominal diameter 8″
• 200mm
• Overall diameter 210mm
• Baffle cutout diameter 191mm
• Overall depth 93mm
• Flange thickness 9mm
• Mounting depth 85mm
• Volume occupied by the driver (estimated) 1.1L
• Net weight 3.6kg