YAMAHA NS-500YST

Commentary

This is a speaker system with improved bass reproduction using the Yamaha YST system.
With the development and adoption of a YST woofer system and a high-performance tweeter, a single mid-range unit covers all of the vocal band, resulting in a vocal-full-range configuration.

A YST-type woofer system is used to achieve ultra-low-frequency playback and achieve low-frequency playback at 22 hz.
This system drives the woofer with negative resistance to resonate the air inside the cabinet, and uses the air itself inside the port as a diaphragm to extract ultra-low sound pressure. Compared to the conventional system in which the woofer directly outputs sound pressure, this system is more efficient, can be greatly miniaturized, and has low amplitude distortion and magnetic distortion.
This YST has been adopted as a super-woofer system, and the Woofer System Division, which includes both woofer and air woofer units, is structured independently from the middle and high range units.

A 25 cm pure cross carbon cone type woofer is used for the low range.
By the YST method, the negative resistance circuit drives with an accuracy of infinite damping factor in the sound pressure range, and the woofer unit also has low distortion because the ultra-low band that supplies energy to the air woofer lives with very little vibration.
In order to take advantage of this low-distortion feature, we have eliminated the LC network, which is susceptible to electrical and mechanical interference, and adopted an electronic network for the woofer.

A 12 cm cone type squaker with a center cap of evaporated beryllium on a pure cross carbon diaphragm is used for the mid-range. This unit can be used as a single unit for the full range of 100 Hz to 20 kHz (-10dB). Especially for 300 Hz to 6 kHz, it is almost flat.
Pure Cross Carbon is a woven material of pure carbon fiber, and it has high rigidity and light weight by molding it in a catenary shape with the rate fiber with the back surface.
In addition, by using double magnets and long voice coils in the magnetic circuit, we have achieved broadband and flat characteristics.

A 3-cm dome type tweeter with beryllium vapor-deposited on a titanium base is adopted for the high frequency band.
Compared with titanium alone, it is lighter and more rigid to eliminate unnecessary high-frequency vibrations outside the band. In addition, the aluminum voice coil directly connected to the diaphragm is totally lighter to realize a high-frequency range of up to 30 kHz.

The enclosure consists of high-density particleboards with 30 mm baffle plates and 25 mm thickness. In addition, angle block and reinforcing bars have been adopted, and the partition walls for independent chambers for medium and high-range units have been strengthened.

A large terminal with gold-plated terminal is used for the speaker terminal.

Model Rating

Method	4-way, 3-Speaker, YST System, Bookshelf Type, Anti-magnetic Design
Units Used	For low band : 25 cm cone type For Medium Range : 12 cm cone type For High Pass : 3 cm Dome Type
Woofer Port Diameter	6.75cm
Playback frequency band	22 Hz to 30000 Hz
Crossover frequency	250 Hz, 4000 Hz (12dB/oct.)
Output sound pressure level	92dB/W/m
Allowable input	70W
Music acceptance input	140W
External dimensions	Width 340x Height 700x Depth 337.5 mm
Weight	30kg
Attachment	Speaker cord (4m)