B&C Speaker 21DS115

• Sensitivity (1W, 1m, infinite baffle) SPL1W 96.6dB
• Frequency response 30 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 30Hz
• Mechanical quality factor QMS 11.00
• Electrical quality factor QES 0.20
• Total quality factor QTS 0.21

Large signal parameters

• Maximum linear excursion xmax 15mm
• Air volume displaced at xmax VD 2520cm³
• Power handling P 1700W
• Program power Pmax 3400W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 2.2Ω
• Inductance (1kHz) LE 2.4mH
• VC Diameter 116mm
• Winding height HVC 36mm
• Winding material Aluminium
• Former material Glass Fibre

Magnet

• Flux density B 0.8T
• Force factor Bl 28.8N/A
• Motor constant Bl/√RE 19.4N/√W
• Air gap height HAG 14mm
• Material Neodymium Inside Slug

Diaphragm

• Effective diameter 462mm
• Effective area SD 1680cm²
• Moving mass MMS 412g
• Moving mass (without air load) MMD 364g
• Material Waterproof Both Sides

Suspensions

• Stiffness KMS 14.3N/mm
• Compliance CMS 70µm/N
• Equivalent volume to the compliance VAS 274L
• Mechanical resistance RMS 7.06N·s/m
• Spider material Silicone

Dimensions

• Nominal diameter 21″
• 530mm
• Overall diameter 547mm
• Baffle cutout diameter 508mm
• Overall depth 255mm
• Flange thickness 13mm
• Mounting depth 242mm
• Volume occupied by the driver 15L
• Net weight 14.7kg