Rutcho's Audio Page dedicated to Hi-End Audio Systems Fullrange Speakers Tube Amplifiers

Ruitcho's page dedicated to hi-end audio Blackswift Audio Logo

B&W ZZ12831

Bowers Wilkins BW ZZ12831 6.5 inch mid-woofer

B&W ZZ12831 is a midbass driver used in B&W DM 601 S3 systems.

Bowers Wilkins BW ZZ12831 6.5 inch mid-woofer back

Like the other midbass drives, used in the B&W 600 series, ZZ12831 has very well casted aluminum alloy chassis with very attractive design.

Bowers Wilkins BW ZZ12831 6.5 inch mid-woofer cone

The half-roll surround has unusual grey color just to correspond to the system's front panel. The phase plug is little bit disappointing - in fact this is a plastic dust cap and it moves with the cone, instead to be attached ti the center pole of the magnet system. 

My Measurements

Driver Properties Thiele - Small Parameters
Chassis material Die Cast Aluminum Alloy    Parameter Measured Datasheet
Membrane material Woven Kevlar Fs 49.0 Hz N/A
Magnet System Ferrite Re 3.5 Ω N/A
Surround Rubber  Qms 7.54 N/A
Voice Coil Diameter 38 mm Qes 0.64 N/A
Nominal Impedance 8 Ω Qts 0.59 N/A
Sensitivity 90 dB/W/m   Vas 19 ltr N/A
Rated Power N/A Le 0.47 mH N/A

Bowers Wilkins BW ZZ12831 SPL Responce at 1m on axis and 15 30 deg off axis

Frequency response at 1m with 2.83 V input RED - on axis, BLUE - 15 º off axis, GREEN - 30 º off axis

Bowers Wilkins BW ZZ12831 THD Graph

The second, third and fourth harmonic curves measured at 2.83V input RMS.

Bowers Wilkins BW ZZ12381 Burst decay Responce at 1m in 38 ltr sealed box

Burst decay response, measured at 1m on axis

Bowers Wilkins BW ZZ12831 impedance in 38 ltr seled box

The impedance curve in 18 ltr sealed box


Although this driver was used by B&W in a compact bass-reflex enclosure it will perform best in a TL or TQWT system.

Arrow up icon To The Top Arrow up icon