Hertz Mille MPS 250 S4

• Sensitivity (1W, 1m, infinite baffle) SPL1W 83.4dB
• Frequency response 25 - 400Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 29Hz
• Mechanical quality factor QMS 5.60
• Electrical quality factor QES 0.52
• Total quality factor QTS 0.48

Large signal parameters

• Maximum linear excursion xmax 16.8mm
• Maximum excursion before damage xlim 20mm
• Air volume displaced at xmax VD 619cm³
• Power handling P 500W
• Program power Pmax 1000W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.3Ω
• Inductance (1kHz) LE 3.65mH
• VC Diameter 38mm

Magnet

• Force factor Bl 17.3N/A
• Motor constant Bl/√RE 9.52N/√W
• Diameter 134mm
• Height 36mm
• Material Ferrite

Diaphragm

• Effective diameter 217mm
• Effective area SD 369cm²
• Moving mass MMS 234g
• Moving mass (without air load) MMD 229g
• Material Polypropylene

Suspensions

• Stiffness KMS 9.09N/mm
• Compliance CMS 110µm/N
• Equivalent volume to the compliance VAS 21.2L
• Mechanical resistance RMS 7.61N·s/m

Dimensions

• Nominal diameter 10″
• 250mm
• Overall diameter 275mm
• Baffle cutout diameter 232mm
• Overall depth 103mm
• Flange thickness 20mm
• Mounting depth 83mm
• Volume occupied by the driver (estimated) 1.8L
• Net weight 5.11kg