Celestion NTR08-2009D

• Sensitivity (1W, 1m, infinite baffle) SPL1W 94.1dB
• Frequency response 70 - 5000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 71.4Hz
• Mechanical quality factor QMS 2.04
• Electrical quality factor QES 0.24
• Total quality factor QTS 0.21

Large signal parameters

• Maximum linear excursion xmax 6.5mm
• Air volume displaced at xmax VD 148cm³
• Power handling P 200W
• Program power Pmax 400W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.5Ω
• Inductance (1kHz) LE 0.48mH
• VC Diameter 50mm
• Winding height HVC 18mm
• Winding material Edgewound copper
• Former material Glass fibre

Magnet

• Force factor Bl 18N/A
• Motor constant Bl/√RE 7.69N/√W
• Air gap height HAG 10mm
• Material Neodymium

Diaphragm

• Effective diameter 170mm
• Effective area SD 227cm²
• Moving mass MMS 31.1g
• Moving mass (without air load) MMD 28.4g
• Material Kevlar loaded paper (weather-resistant)

Suspensions

• Stiffness KMS 6.25N/mm
• Compliance CMS 160µm/N
• Equivalent volume to the compliance VAS 11.7L
• Mechanical resistance RMS 6.85N·s/m
• Surround material Cloth-sealed

Dimensions

• Nominal diameter 8″
• 203mm
• Overall diameter 225mm
• Baffle cutout diameter 187mm
• Overall depth 100mm
• Volume occupied by the driver (estimated) 1L
• Net weight 2.8kg
• Frame material Cast aluminium