B&C Speaker 21IPAL

• Sensitivity (1W, 1m, infinite baffle) SPL1W 96.6dB
• Frequency response 37 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 37Hz
• Mechanical quality factor QMS 4.90
• Electrical quality factor QES 0.22
• Total quality factor QTS 0.21

Large signal parameters

• Maximum linear excursion xmax 22mm
• Air volume displaced at xmax VD 3696cm³
• Power handling P 2500W
• Program power Pmax 5000W

Voice Coil

• Nominal impedance Z 1Ω
• DC resistance RE 0.7Ω
• Inductance (1kHz) LE 0.5mH
• VC Diameter 153mm
• Winding height HVC 48mm
• Winding material Aluminium
• Former material Glass Fibre

Magnet

• Flux density B 1.35T
• Force factor Bl 19.1N/A
• Motor constant Bl/√RE 22.8N/√W
• Air gap height HAG 18mm
• Material Neodymium Inside Slug

Diaphragm

• Effective diameter 462mm
• Effective area SD 1680cm²
• Moving mass MMS 487g
• Moving mass (without air load) MMD 439g
• Material Waterproof Both Sides

Suspensions

• Stiffness KMS 26.3N/mm
• Compliance CMS 38µm/N
• Equivalent volume to the compliance VAS 155L
• Mechanical resistance RMS 23.1N·s/m
• Spider material Silicone

Dimensions

• Nominal diameter 21″
• 530mm
• Overall diameter 547mm
• Baffle cutout diameter 508mm
• Overall depth 269mm
• Flange thickness 13mm
• Mounting depth 256mm
• Volume occupied by the driver 16L
• Net weight 23.0kg