YAMAHA NS-20

Commentary

A speaker system that uses Yamaha's unique low-frequency unit.

Yamaha's original NS type Woofer JA-5002 is mounted in the low range.
The NS type was developed with a hint from the soundboard of a piano. It pursues the split vibration produced by the bending of the board, which is completely different from the piston motion of a cone speaker. The diaphragm is made of a unique plastic foam selected from more than 200 tests. This prevents quality changes due to external humidity. Moreover, since the specific gravity is extremely light, the efficiency of the electrical energy required for vibration is excellent.
The drive part uses Yamaha's patented super anisotropic high-performance magnet to reduce distortion.
The characteristics of this unit are that the sound spreads well because the area of the diaphragm is wide, and that the directional characteristic does not depend on the frequency when viewed macroscopically because the unit is a multiresonance system and vibrates in many regions in the high-frequency range. It is also fully usable in a rear open enclosure, and there is no need to consider the compliance of the air inside the box in a sealed box.

The mid-range is equipped with JA 2053 which is a 20 cm cone type squaker.

As for the high-frequency unit, it seems that different ones were installed in the early period and the latter period.
In the initial stage, it is equipped with JA 0503 which is a 5 cm horn type tweeter, and in the later stage, it is equipped with JA 0505 which is a 5 cm horn type tweeter.

Level control is provided for the middle and high frequencies.

The enclosure has a unique layout with an open front and a rear mounted JA-5002.
Because of this layout, we recommended that it be installed at least 5-10 cm away from the wall.
19 mm lauan plywood was used for the plate material, and the exterior was finished with American Walnut. The net on the front is removable.

Model Rating

Method	3-way, 3-speaker, front open system, floor type
Units Used	For Low Band : NS Type (JA-5002) For Middle Range : 20 cm Cone Type (JA-2053) For High Range : Horn Type (JA-0503 or JA-0505)
Playback frequency band	50 Hz to 18 kHz
Crossover frequency	200 Hz, 8 kHz (6, 12dB/oct.)
Impedance	8 Ω
Output sound pressure level	102dB/W
Allowable input	20W (continuous)
External dimensions	Width 620x Height 860x Depth 310 mm
Weight	23kg