Celestion TF1220

• Sensitivity (1W, 1m, infinite baffle) SPL1W 95.9dB
• Frequency response 60 - 4000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 55.8Hz
• Mechanical quality factor QMS 3.33
• Electrical quality factor QES 0.44
• Total quality factor QTS 0.39

Large signal parameters

• Maximum linear excursion xmax 4mm
• Air volume displaced at xmax VD 212cm³
• Power handling P 150W
• Program power Pmax 300W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.5Ω
• Inductance (1kHz) LE 0.71mH
• VC Diameter 50mm
• Winding height HVC 12mm
• Winding material Round copper
• Former material Polyimide

Magnet

• Force factor Bl 13.9N/A
• Motor constant Bl/√RE 5.95N/√W
• Air gap height HAG 8mm
• Weight 1.2kg
• Material Ferrite

Diaphragm

• Effective diameter 260mm
• Effective area SD 531cm²
• Moving mass MMS 44.5g
• Moving mass (without air load) MMD 35.9g
• Material Kevlar loaded paper

Suspensions

• Stiffness KMS 5.56N/mm
• Compliance CMS 180µm/N
• Equivalent volume to the compliance VAS 72.8L
• Mechanical resistance RMS 4.69N·s/m
• Surround material Cloth-sealed

Dimensions

• Nominal diameter 12″
• 305mm
• Overall diameter 309mm
• Baffle cutout diameter 283mm
• Overall depth 131mm
• Volume occupied by the driver (estimated) 1.9L
• Net weight 4.0kg
• Frame material Pressed steel