Peerless M21WO39-04

• Sensitivity (1W, 1m, infinite baffle) SPL1W 90dB
• Frequency response 20 - 10000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 30.9Hz
• Mechanical quality factor QMS 2.84
• Electrical quality factor QES 0.33
• Total quality factor QTS 0.29

Large signal parameters

• Maximum linear excursion xmax 5.9mm
• Air volume displaced at xmax VD 142cm³
• Power handling P 80W
• Program power Pmax 160W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 2.8Ω
• Inductance (1kHz) LE 0.24mH
• VC Diameter 38.6mm
• Former material Aluminium

Magnet

• Force factor Bl 6.76N/A
• Motor constant Bl/√RE 4.02N/√W
• Air gap height HAG 6mm

Diaphragm

• Effective diameter 175mm
• Effective area SD 241cm²
• Moving mass MMS 27.1g
• Moving mass (without air load) MMD 24.5g

Suspensions

• Stiffness KMS 1.02N/mm
• Compliance CMS 980µm/N
• Equivalent volume to the compliance VAS 79.7L
• Mechanical resistance RMS 1.85N·s/m

Dimensions

• Nominal diameter 8″
• 203mm
• Volume occupied by the driver (estimated) 0.76L
• Net weight 1.86kg