https://www.youtube.com/watch?v=7yLUzGbD0B8
https://audio-heritage.jp/YAMAHA/speaker/ns-1000m.html
A speaker system developed by introducing Yamaha's original technology such as beryllium diaphragm, based on the basic idea of creating something that will be used as a reference for a long time.
It was sold for a long period of 23 years from 1974 to 1997, and was used as a monitor speaker on Swedish and Finnish national broadcasts.
The beryllium diaphragm is adopted as a diaphragm of a mid-high range.
This vibrating plate has been successfully developed by applying the electron beam vacuum deposition method and special alloy technology used in LSI manufacturing technology, and is finished with rolled plate material because it is manufactured in high vacuum. It has less compounds than the ones and achieves high purity.
In addition, since it is once made into an atomic or plasma form and then vapor-deposited, it is possible to manufacture products with deep dome shapes and tangential edges that are difficult to draw.
Furthermore, by applying a special coating to the beryllium material, which is easily corroded, with a thickness of about 5 microns, we have succeeded in protecting it from harmful components in the atmosphere.
JA-3058A which is a 30cm cone type Woofer is carried in the low-pass.
The corrugated cone paper developed from the accumulated experience of material research for many years is adopted as a diaphragm. Moreover, the cloth which double-coated the thermosetting resin and the viscoelastic resin which suppresses resonance is used for the edge, and the linearity to an input signal is raised.
The ferrite magnet of 156φ is adopted as a magnetic circuit, and the voice coil is an edgewise winding of a copper ribbon wire.
JA-0801 which is an 8.8cm dome type squawker is carried in the mid range.
A beryllium diaphragm with a diaphragm diameter of 68 mm is used, which is manufactured by Yamaha's original method. In addition, the edge uses a double-coated tangential edge impregnated with viscoelastic resin and thermosetting resin, which was the result of research when developing a soft dome type such as NS-690, and is sufficient without impairing the features of beryllium. It has a good shape retention and center retention ability. Moreover, the voice coil adopts a large diameter of 66φ, and the efficiency is increased by using the copper ribbon wire edgewise winding.
This vibration system is designed so that the air pressure behind each part such as the beryllium diaphragm, voice coil, and edge is the same. The back of the diaphragm leads to the hollowed back cavity of the center pole, and the back of the voice coil is passed through the back cavity by making an air hole in the bottom plate of the magnetic circuit. In addition, behind the edge, an air hole is made in the outer pole through the air hole of the voice coil bobbin to let the air in the edge part escape.
The large magnet of 156φ is adopted as a magnetic circuit, the magnetic flux density 16,000gauss is obtained, and the transient characteristic is improved.
A dome shape with a small radius of curvature is adopted to increase the rigidity and directivity of the diaphragm. For this reason, the valley caused by interference caused by the on-axis characteristics outside the band is suppressed by adopting a diffuser, the on-axis characteristics are extended as wide as possible, and the connection with the tweeter near the crossover frequency is improved. I will.
JA-0513 which is a 3.0cm dome shape tweeter is carried in the high region.
A 23mm lightweight diaphragm with a weight of 0.03g or less that makes the best use of the characteristics of beryllium material is used for the diaphragm, and a tangential edge made of cloth that is double-coated with viscoelastic resin and thermosetting resin is used, which is unnecessary. Resonance is suppressed.
The voice coil diameter is 23 mm, and the aluminum wire edgewise winding directly connected to the beryllium diaphragm is adopted, and the entire vibration system is also lightweight.
In addition, the influence of resonance is suppressed by tapering the center pole in the space behind the voice coil, which is the research result of the tweeter of NS-690, and filling it with urethane for sound absorption.
In the design of the network part, not only the check of electrical characteristics but also the basic actual hearing feeling is emphasized, and the audition is repeatedly decided by cut and try.
The DC resistance is reduced and the input resistance is improved by adopting a bobbin with a large-diameter ferrite core using a 1.0φ formal wire for the Woofer circuit.
Moreover, the attenuator which sets the level of a squawker and a tweeter is a large one with a good input resistance characteristic of a double winding.
The enclosure has a completely sealed bookshelf-type 4-sided finish with a black finish design.
The NS-1000M uses a particle board with a front baffle of 24 mm, a back plate of 25 mm, a side plate, a top plate, and a bottom plate of 20 mm. Furthermore, a 24mm thick plywood is passed over the back plate to the upper part of the woofer mounting hole to make it a strong reinforcing material, and appropriate reinforcement is given to each part.
The finish is a black semi-gloss finish without a cross net.
