Celestion TF1525

• Sensitivity (1W, 1m, infinite baffle) SPL1W 95.6dB
• Frequency response 40 - 3000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 47.6Hz
• Mechanical quality factor QMS 3.84
• Electrical quality factor QES 0.56
• Total quality factor QTS 0.49

Large signal parameters

• Maximum linear excursion xmax 4.5mm
• Air volume displaced at xmax VD 385cm³
• Power handling P 250W
• Program power Pmax 500W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.2Ω
• Inductance (1kHz) LE 0.9mH
• VC Diameter 64mm
• Winding height HVC 13mm
• Winding material Round copper
• Former material Polyimide

Magnet

• Force factor Bl 14.6N/A
• Motor constant Bl/√RE 6.42N/√W
• Air gap height HAG 8mm
• Weight 1.2kg
• Material Ferrite

Diaphragm

• Effective diameter 330mm
• Effective area SD 855cm²
• Moving mass MMS 77.9g
• Moving mass (without air load) MMD 60.6g
• Material Kevlar loaded paper

Suspensions

• Stiffness KMS 7.14N/mm
• Compliance CMS 140µm/N
• Equivalent volume to the compliance VAS 148L
• Mechanical resistance RMS 6.08N·s/m
• Surround material Cloth-sealed

Dimensions

• Nominal diameter 15″
• 381mm
• Overall diameter 385mm
• Baffle cutout diameter 351mm
• Overall depth 153mm
• Volume occupied by the driver (estimated) 2.9L
• Net weight 5.2kg
• Frame material Pressed steel