Lowther A55

• Sensitivity (1W, 1m, infinite baffle) SPL1W 94.1dB
• Frequency response 80 - 22000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 82Hz
• Mechanical quality factor QMS 5.83
• Electrical quality factor QES 0.38
• Total quality factor QTS 0.36

Large signal parameters

• Maximum linear excursion xmax 1mm
• Air volume displaced at xmax VD 11cm³
• Power handling P 100W
• Program power Pmax 200W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 7.4Ω
• Inductance (1kHz) LE 0.115mH
• VC Diameter 39mm

Magnet

• Flux density B 1.98T
• Force factor Bl 9.71N/A
• Motor constant Bl/√RE 3.57N/√W
• Air gap height HAG 5mm
• Diameter 97mm
• Material Alcomax 3

Diaphragm

• Effective diameter 116mm
• Effective area SD 106cm²
• Moving mass MMS 7.62g
• Moving mass (without air load) MMD 6.7g
• Material Twin Paper

Suspensions

• Stiffness KMS 3.72N/mm
• Compliance CMS 269µm/N
• Equivalent volume to the compliance VAS 4.25L
• Mechanical resistance RMS 0.67N·s/m

Dimensions

• Nominal diameter 7″
• 174mm
• Overall diameter 174mm
• Baffle cutout diameter 137mm
• Overall depth 110mm
• Flange thickness 9mm
• Mounting depth 101mm
• Volume occupied by the driver (estimated) 0.78L