BOSE 464 WestBorough

Commentary

The grand music monitor was developed by fusing the latest technology while inheriting the blood line of the Westborough series.

The 464 WestBorough uses an advanced Kusu architectural approach to the enclosure.
In this system, Bose's patented technology is combined with passive radiators to convert energy from the front and rear of the Kusu into resonance energy with higher efficiency.
The inside consists of two rooms. A woofer unit is mounted inside. A passive radiator is placed on the large chamber side located on the back of the woofer (front baffle), and a spiral port is placed on the small chamber side. Heavy bass at around 40 Hz, which tends to generate port noise and incidental sound, is played back by the passive radiator. Bass at around 90 Hz is played back through the spiral port. This makes it possible to cover a wide range of frequencies by synergizing the outputs. Flat and high-efficiency bass is obtained while suppressing the movement of the cone paper.

A 20 cm cone type woofer and a 20 cm passive radiator are installed in the low range.
The Woofer Unit is reinforced with voice coils and magnets for excellent linearity and wide tolerance, while the passive radiator and the frame of the woofer are made of magnesium for increased rigidity and reduced vibration.

A newly developed resonance matrix is used for the mid-range and high-range.
In this technology, two mid-range drivers are placed one above the other via a magnesium baffle to create a phantom sound source at the midpoint of the two mid-range drivers, and a tweeter is placed at the location of the phantom sound source to create a virtual coaxial speaker that combines two mid-range drivers and a tweeter.
In addition, the resonance matrix reduces interference between drivers, which is a cause of sound coloring. The resonance matrix focuses on the fact that the frequency at which interference occurs increases as the distance between drivers increases. By using a neodymium magnet in the tweeter, the distance between two mid-range drivers is minimized and the interference area is as close to 0 as possible.
Magnesium, which is also used in commercial optical equipment and digital information equipment, is used for the sub-baffle. By using the magnesium injection manufacturing method instead of the general die casting manufacturing method, accurate and uniform metal molding of ± 1/100mm is possible.

The mid-range features two 11.5 cm cone mid-range drivers.
Since this unit can play back up to the mid-bus band of 200 Hz, it can play back the vocal band with natural sound without any joints. In addition, the voice coil employs a helical voice coil with aluminum edgewise winding patented by Bose, and by precise computer control, aluminum ribbon wire with square cross section is wound around an aluminum bobbin with no gap, improving magnetic field energy efficiency and obtaining excellent transient response.

A newly developed 2.5 cm titanium dome type tweeter is installed in the high-frequency range.
By using titanium for the diaphragm, high sound velocity and high elastic modulus are realized, and by using tangential type for the edge, excellent linearity is ensured.
A ring-shaped equalizer is installed on the front to improve the performance.

The enclosure is designed for uniform strength through strength analysis using Bose's unique technique.
The top and bottom plates are equipped with MDF, which has excellent hardness and internal loss relative to specific gravity, and the side board is equipped with high compression and high specific gravity particle board, which is set in a corridor shape as reinforcement. By combining materials with different resonance modes, resonance and box rumbling are suppressed.
In addition, the MDF is made of only conifer wood, which is used for musical instruments. This not only reduces resonance but also realizes the beauty of the musical sound.
The vertical structure of the partition between the front and rear chambers and the inner wall of the spiral port is doubled to ensure rigidity, and the large chamber inside the enclosure suppresses standing waves between the inner walls.

High-quality film capacitors with high linearity and no loss of capacity due to aging are used for the capacitors arranged in series in the network, and air-core coils are used for all coils to prevent distortion due to magnetic field.
The 464 The West Borough network is designed for bi-wiring so that it can be connected independently to the amplifier by separating the low band from the high band.

The speaker terminal uses a gold-plated terminal that supports banana plugs.

Anti-magnetic measures using both shield method and canceling magnet method are provided.
In addition, the tweeter has an internal magnetic structure in which the magnet is not exposed to the outside.

There was a special speaker stand sold separately.

Model Rating

Method	3-way, 4-speaker, bookshelf type, magnetic protection design Medium and low frequency : resonance matrix method Low Pass : Advanced Kusu Timas
Units Used	For low band : 20 cm cone type For Medium Range : 11.5 cm Cone Type x2 For high-pass : 2.5 cm dome type Other : 20 cm passive radiator
Playback frequency band	38 Hz to 35 kHz
Impedance	6 Ω
Allowable input	100W(rms IEC268-5)
Low flux leakage	Low and Middle Band : Shield method and Canceling / Magnet Method Combined High Frequency : Inner Magnetic Type
Input terminal	Bi-wiring enabled Screw Type (Gold Plated) for Dual Banana
Color	Cabinet : Metallic Brown-Gray Side Panel : Dark Gold-Brown
External dimensions	Width 310x Height 606x Depth 310 mm
Weight	20kg
Attachment	Speaker cables (2 pieces of 3 m x)
Sold Separately : Dedicated Floor Stand SP-4 (2 Units 1 Set, ¥ 30,000)
External dimensions	Width 340x Height 504x Depth 350 mm