Eighteen Sound 21LW2500

• Sensitivity (1W, 1m, infinite baffle) SPL1W 94.4dB
• Frequency response 30 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 29Hz
• Mechanical quality factor QMS 22.00
• Electrical quality factor QES 0.38
• Total quality factor QTS 0.37

Large signal parameters

• Maximum linear excursion xmax 14mm
• Maximum excursion before damage xlim 35mm
• Air volume displaced at xmax VD 2324cm³
• Power handling P 1600W
• Program power Pmax 3200W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 4.9Ω
• Inductance (1kHz) LE 2.58mH
• VC Diameter 100mm
• Winding material Copper

Magnet

• Force factor Bl 30N/A
• Motor constant Bl/√RE 13.6N/√W
• Material Ferrite

Diaphragm

• Effective diameter 460mm
• Effective area SD 1660cm²
• Moving mass MMS 380g
• Moving mass (without air load) MMD 333g
• Material Curved ribbed fiber loaded cellulose

Suspensions

• Stiffness KMS 12.8N/mm
• Compliance CMS 78µm/N
• Equivalent volume to the compliance VAS 305L
• Mechanical resistance RMS 3.15N·s/m
• Surround material Triple roll, Heavy Polycotton

Dimensions

• Nominal diameter 21″
• 533mm
• Overall diameter 545mm
• Baffle cutout diameter 490mm
• Overall depth 252mm
• Flange thickness 18mm
• Mounting depth 234mm
• Volume occupied by the driver (estimated) 11L
• Net weight 17.9kg