Dayton Audio Ultimax UM12-22

• Sensitivity (1W, 1m, infinite baffle) SPL1W 83.1dB
• Frequency response 20 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 31.8Hz
• Mechanical quality factor QMS 2.90
• Electrical quality factor QES 1.05
• Total quality factor QTS 0.77

Large signal parameters

• Maximum linear excursion xmax 19mm
• Air volume displaced at xmax VD 933cm³
• Power handling P 600W
• Program power Pmax 1200W

Voice Coil

• Nominal impedance Z 2 x 2Ω
• DC resistance (in series) RE 3.7Ω
• Inductance (1kHz, in series) LE 0.78mH
• VC Diameter 63.5mm
• Winding material Copper
• Former material Aluminum

Magnet

• Force factor (in series) Bl 12N/A
• Motor constant Bl/√RE 6.24N/√W
• Material Ferrite

Diaphragm

• Effective diameter 250mm
• Effective area SD 491cm²
• Moving mass MMS 206g
• Moving mass (without air load) MMD 198g
• Material Nomex

Suspensions

• Stiffness KMS 8.33N/mm
• Compliance CMS 120µm/N
• Equivalent volume to the compliance VAS 41.1L
• Mechanical resistance RMS 14.2N·s/m
• Surround material Rubber

Dimensions

• Nominal diameter 12″
• 315mm
• Overall diameter 315mm
• Baffle cutout diameter 285mm
• Overall depth 158mm
• Volume occupied by the driver (estimated) 2.8L
• Frame material Cast Aluminium