Radian 2218

• Sensitivity (1W, 1m, infinite baffle) SPL1W 91.3dB
• Frequency response 26 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 33.8Hz
• Mechanical quality factor QMS 3.16
• Electrical quality factor QES 0.63
• Total quality factor QTS 0.52

Large signal parameters

• Maximum linear excursion xmax 4.8mm
• Air volume displaced at xmax VD 616cm³
• Power handling P 750W
• Program power Pmax 1500W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 6.3Ω
• Inductance (1kHz, estimated) LE 6.71mH
• VC Diameter 101.6mm
• Winding material Edgewood Aluminum

Magnet

• Force factor Bl 26.8N/A
• Motor constant Bl/√RE 10.7N/√W
• Material Ferrite

Diaphragm

• Effective diameter 406mm
• Effective area SD 1297cm²
• Moving mass MMS 336g
• Moving mass (without air load) MMD 304g
• Material Kevlar Reinforced Paper

Suspensions

• Stiffness KMS 15.2N/mm
• Compliance CMS 66µm/N
• Equivalent volume to the compliance VAS 159L
• Mechanical resistance RMS 22.6N·s/m

Dimensions

• Nominal diameter 18″
• 465mm
• Overall diameter 465mm
• Baffle cutout diameter 429mm
• Overall depth 193mm
• Volume occupied by the driver (estimated) 6.4L
• Net weight 11.8kg
• Frame material Cast Aluminum