B&W 801

Commentary

A typical B & W monitor speaker.

The 801 has been used as a monitor speaker at EMI Abbey Road Studio in the UK, as well as at CBS, Polydor and Gramophone studios.

A 30 cm cone type woofer is installed in the low range.
The acoustic power output of a woofer system is determined by the displacement of the diaphragm and is proportional to the second power of the volume displacement at the peak of the diaphragm. In 801, it is designed based on the peak voltage value of the spectrum of an organ record, which can be regarded as the maximum displacement of the music signal. In this case, the displacement value is calculated as 5.4 mm to obtain the acoustic power output of 1W. In 801, the pole piece has 6 mm overhangs on both sides of the pole piece to prevent distortion even if it is displaced 6 mm at the peak. In addition, by using a special magnet assembly, the displacement is limited by the reaction of the inner suspension so that the voice coil does not hit the back plate of the magnet even if it is displaced more than 6 mm.
Flexible PVC is used for the edge part, and Nomex type with excellent heat resistance of 50 mm diameter is used for the voice coil to enhance the green body.

The mid-range is equipped with a 10 cm cone type squaker.
In this unit, the diaphragm diameter was determined to be 100 mm in order to obtain a flat frequency characteristic up to 5 kHz. The cone uses a resin-coated Kevlar made by a special manufacturing method patented by B & W. In addition, vibration of the diaphragm is analyzed with a laser beam. While taking advantage of the characteristics of Kevlar, which has excellent transient characteristics and does not store energy, superior mid-range regeneration has been realized by introducing technologies such as improvement of the edge and ring-shaped coating of dump material.

A 2.6 cm dome-shaped tweeter is installed in the high range.
This unit is designed to be extremely compact in order to achieve excellent directional characteristics in the high frequency band. The diaphragm is a dome shaped braided polyester filament driven by a 26 mm diameter voice coil. Nickel cobalt is used for the center pole magnet.

In the network section, the impedance of the voice coil itself changes with frequency, so we design the network using a computer. The constant of the element is determined by the optimal value method to realize a low-distortion network.

Mid-range and high-range level controls on the back of the mid-range enclosure
You can adjust the sound characteristics according to the condition of the listening room.

The enclosure is designed using a unique vibration measurement method and uses a unique internal structure with frame-like reinforcement. In addition, each unit has an independent enclosure for the low, middle and high frequency ranges. Moreover, the middle and high frequency range enclosure can be turned independently of the woofer to improve directional characteristics.
The exterior has a walnut finish.

An automatic overload protection circuit protects the speakers from transient signals such as clicks, thermal overloads that can damage the voice coil, and amplifier DC leaks.
In an overload condition, the LED lights up and the input signal to the speaker is automatically cut off.

Model Rating

Method	3-Way, 3-Speaker, Airtight System, Floor Type
Units Used	For low band : 30 cm cone type For Medium Range : 10 cm Cone Type For high-pass : 2.6 cm dome type
Frequency characteristic	45 Hz ~ 20 kHz ± 2 dB (2m)
Lowest resonance frequency	37Hz
Impedance	8 Ω
Output sound pressure level	85dB/W/m
External dimensions	Width 432x Height 948x Depth 560 mm
Weight	44kg