Dayton Audio Reference RS225P-4A

• Sensitivity (1W, 1m, infinite baffle) SPL1W 88.6dB
• Frequency response 35 - 5500Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 37.7Hz
• Mechanical quality factor QMS 1.85
• Electrical quality factor QES 0.48
• Total quality factor QTS 0.38

Large signal parameters

• Maximum linear excursion xmax 6mm
• Air volume displaced at xmax VD 128cm³
• Power handling P 80W
• Program power Pmax 120W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.3Ω
• Inductance (1kHz) LE 0.51mH
• VC Diameter 38.5mm

Magnet

• Force factor Bl 6.4N/A
• Motor constant Bl/√RE 3.52N/√W
• Material Ferrite

Diaphragm

• Effective diameter 165mm
• Effective area SD 214cm²
• Moving mass MMS 25g
• Moving mass (without air load) MMD 22.6g
• Material Paper / Kevlar

Suspensions

• Stiffness KMS 1.41N/mm
• Compliance CMS 710µm/N
• Equivalent volume to the compliance VAS 45.8L
• Mechanical resistance RMS 3.2N·s/m
• Surround material Rubber

Dimensions

• Nominal diameter 8″
• 223mm
• Overall diameter 223mm
• Baffle cutout diameter 184mm
• Overall depth 84mm
• Volume occupied by the driver (estimated) 0.76L
• Frame material Cast Aluminium