Celestion TF1225CX

• Sensitivity (1W, 1m, infinite baffle) SPL1W 95.6dB
• Frequency response 40 - 18000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 63.5Hz
• Mechanical quality factor QMS 3.12
• Electrical quality factor QES 0.41
• Total quality factor QTS 0.36

Large signal parameters

• Maximum linear excursion xmax 4.5mm
• Air volume displaced at xmax VD 239cm³
• Power handling P 250W
• Program power Pmax 500W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.6Ω
• Inductance (1kHz) LE 1.2mH
• VC Diameter 64mm
• Winding height HVC 13mm
• Winding material Round copper
• Former material Polyimide

Magnet

• Force factor Bl 17.5N/A
• Motor constant Bl/√RE 7.4N/√W
• Air gap height HAG 8mm
• Weight 1.2kg
• Material Ferrite

Diaphragm

• Effective diameter 260mm
• Effective area SD 531cm²
• Moving mass MMS 55.6g
• Moving mass (without air load) MMD 47g
• Material Kevlar loaded paper

Suspensions

• Stiffness KMS 9.09N/mm
• Compliance CMS 110µm/N
• Equivalent volume to the compliance VAS 45.1L
• Mechanical resistance RMS 7.11N·s/m
• Surround material Cloth-sealed

Dimensions

• Nominal diameter 12″
• 305mm
• Overall diameter 309mm
• Baffle cutout diameter 286mm
• Overall depth 172mm
• Volume occupied by the driver (estimated) 2.5L
• Net weight 4.6kg
• Frame material Pressed steel