Dayton Audio ND90-8

• Sensitivity (1W, 1m, infinite baffle) SPL1W 81.1dB
• Frequency response 80 - 15000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 70.7Hz
• Mechanical quality factor QMS 4.71
• Electrical quality factor QES 0.75
• Total quality factor QTS 0.65

Large signal parameters

• Maximum linear excursion xmax 4mm
• Air volume displaced at xmax VD 13cm³
• Power handling P 20W
• Program power Pmax 40W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 7.5Ω
• Inductance (1kHz) LE 1.08mH
• VC Diameter 19mm
• Winding material Copper
• Former material Kapton® / Polyimide

Magnet

• Force factor Bl 4.3N/A
• Motor constant Bl/√RE 1.57N/√W
• Material Neodymium

Diaphragm

• Effective diameter 63mm
• Effective area SD 31.2cm²
• Moving mass MMS 4.2g
• Moving mass (without air load) MMD 4g
• Material Black Anodized Aluminum

Suspensions

• Stiffness KMS 0.82N/mm
• Compliance CMS 1220µm/N
• Equivalent volume to the compliance VAS 1.77L
• Mechanical resistance RMS 0.4N·s/m
• Surround material Rubber

Dimensions

• Nominal diameter 3.5″
• 104mm
• Overall diameter 104mm
• Baffle cutout diameter 85mm
• Overall depth 61mm
• Volume occupied by the driver (estimated) 0.18L
• Frame material Steel