MW Audio MW-5065: 6.5 Inch Woofer
Boston Acoustics A40 series II woofer copy. Outside diameter is 6.89″.
***The A40 series I woofer is similar, but the screw hole mounting is completely different and the outside diameter is 6.5″. The MW-5065 woofer will NOT fit A40 series I speakers, only series II. Your A40 speaker will only say if it is series II on the back of the cabinet by the terminal cup. If it just says A40 with nothing after it then you have series I. The original A40 series 2 woofer has been discontinued from Boston Acoustics for years now. This woofer features a polypropylene cone with polyether foam surround. All the specs and parameters were copied to ensure similar sound and physical fit. Same impedance (4 ohms), basket size and screw holes, so you do not have to modify the cabinet at all.
*The Boston A40 series II speakers say 8 ohms on the back of the cabinet, but the DC Resistance on the woofers are around 3.6 ohms.
Specifications and Small Signal Parameters:
Voice Coil Impedance: 4 ohm (Just like the original woofers)
Rated Frequency Response: 67- 9k Hz
Sensitivity: 87.8 dB/W(m) SPL
Rated Power: 40 watts
Program Power: 80 watts
Magnet Weight: 231 gr (8.15 oz)
Fs: 67.55 Hz
Re: 3.6 ohm
Vas: 12.012 liters
No: .38 %
Outside Diameter: 6.89″ (175mm)
Cutout Diameter: 6.125″ (155.6mm)