Dayton Audio ND65-4

• Sensitivity (1W, 1m, infinite baffle) SPL1W 78.6dB
• Frequency response 85 - 20000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 89.5Hz
• Mechanical quality factor QMS 5.56
• Electrical quality factor QES 0.68
• Total quality factor QTS 0.61

Large signal parameters

• Maximum linear excursion xmax 3.5mm
• Air volume displaced at xmax VD 5.5cm³
• Power handling P 15W
• Program power Pmax 30W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.5Ω
• Inductance (1kHz) LE 0.44mH
• VC Diameter 19mm
• Winding material Copper
• Former material Kapton® / Polyimide

Magnet

• Force factor Bl 2.68N/A
• Motor constant Bl/√RE 1.43N/√W
• Material Neodymium

Diaphragm

• Effective diameter 45mm
• Effective area SD 15.6cm²
• Moving mass MMS 2.5g
• Moving mass (without air load) MMD 2.5g
• Material Black Anodized Aluminum

Suspensions

• Stiffness KMS 0.794N/mm
• Compliance CMS 1260µm/N
• Equivalent volume to the compliance VAS 0.53L
• Mechanical resistance RMS 0.25N·s/m
• Surround material Rubber

Dimensions

• Nominal diameter 2.5″
• 64mm
• Overall diameter 64mm
• Baffle cutout diameter 52mm
• Overall depth 48mm
• Volume occupied by the driver (estimated) 0.15L
• Frame material Steel