HELIX PURE S 4B

• Sensitivity (1W, 1m, infinite baffle) SPL1W 86.9dB
• Frequency response 75 - 6000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 120Hz
• Mechanical quality factor QMS 4.24
• Electrical quality factor QES 1.11
• Total quality factor QTS 0.88

Large signal parameters

• Maximum linear excursion xmax 3mm
• Air volume displaced at xmax VD 18cm³
• Power handling P 70W
• Program power Pmax 140W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.4Ω
• Inductance (1kHz, estimated) LE 0.25mH
• VC Diameter 25mm
• Winding height HVC 12mm

Magnet

• Force factor Bl 4.1N/A
• Motor constant Bl/√RE 2.22N/√W

Diaphragm

• Effective diameter 88mm
• Effective area SD 61cm²
• Moving mass MMS 5.9g
• Moving mass (without air load) MMD 5.6g

Suspensions

• Stiffness KMS 4.31N/mm
• Compliance CMS 232µm/N
• Equivalent volume to the compliance VAS 1.2L
• Mechanical resistance RMS 1.19N·s/m

Dimensions

• Nominal diameter 4″
• 100mm
• Overall diameter 102mm
• Baffle cutout diameter 92mm
• Mounting depth 47mm
• Volume occupied by the driver (estimated) 0.14L