In Hi-Fi speaker systems, fiber, plastic, and metal used for diaphragms have their own inherent acoustic properties, which in turn give distinctive characteristics to drivers as well as to complete speakers. Over the years, relying on speaker engineers' experience and intuition to fine-tune a unique acoustic characteristic derived from a material into an appealing sound coming from a complete speaker has been an established approach to making speakers; this balancing act continued to present an opportunity for speaker engineers to show off their mastery of speaker development.
Departing from conventional wisdom, Yamaha has taken a novel approach to developing the NS-5000 — starting with selecting a diaphragm material. We have chosen textile made of 100% ZYLON® — a synthetic fiber of exceptionally high strength, having acoustic velocity as well as the ability to reproduce the finest details of audio equivalent to those of beryllium but without a sharp resonance peak inherent in a hard material — that has an acoustic characteristic markedly different from that of any other diaphragm material. This rare material presented a perfect opportunity to create a truly ‘Yamaha-esque’ Hi-Fi speaker, fully capable of meeting the demands of the high-resolution era, and reproducing music in greater faithfulness to the original. To this end, Yamaha began in 2008 to develop a speaker diaphragm made of fiber containing 100% ZYLON®. And now, we have a set of three world's first drivers made of 100% ZYLON® — the JA-05K6 3 cm (1-1/4”) soft-dome tweeter, the JA-08B5 8 cm (3-1/4”) soft-dome midrange, and the JA-3132 30 cm (12”) cone woofer.
In particular, the JA-08B5 8 cm (3-1/4”) midrange — one of the world’s largest dome midranges — most closely symbolises the design philosophy of the NS-5000 — which is to realise the full potential of a 100% ZYLON® diaphragm. The driver's dome configuration allows loss-free movement, and its broad directional characteristic reproduces a rich sound field. Moreover, the NS-5000 incorporates three additional innovations: (1) R.S. (Resonance Suppression) Chambers on the tweeter and midrange cancel out tube resonance from the back of the drivers; (2) Acoustic Absorbers eliminate the need for a large quantity of sound-absorbing material that would dampen the acoustic energy produced by the woofer, and ensure more accurate reproduction of the original dynamism in the music; and (3) An enclosure-reinforced structure, crafted with the use of advanced FEM analysis and meticulous laser measurements, effectively suppresses “box ringing.” All these technological innovations combine to achieve non-coloration and exceptionally wide range — made possible only with ZYLON® — with an unprecedented level of noise-free clarity.
100% ZYLON® 8 cm (3-1/4”) soft-dome midrange — the JA-08B5
The JA-08B5 8 cm (3-1/4”) soft-dome midrange is made of 100% ZYLON®, molded seamlessly from the diaphragm to the surrund (edge) thanks to our proprietary molding technology. The system design of the NS-5000 began with the crafting of this midrange driver. In order to take full advantage of impressive acoustic velocity and realistic acoustic density that the 100% ZYLON® diaphragm provides, we adopted a dome design — which shortens the distance from the voice coil to the diaphragm to a degree impossible with a cone design, resulting in smaller loss of movement — and we made its diameter 8 cm (3-1/4”), which is the largest feasible size that manufacturing yield allows. The high-pass crossover frequency was set at 750 Hz, optimum for bringing out the very best in this driver.
100% ZYLON® 8 cm (3-1/4”) soft-dome midrange
100% ZYLON® 3 cm (1-1/4”) soft dome tweeter – the JA-05K6
Just as with the 8 cm (3-1/4”) mid-range, the JA-05K6 3 cm (1-1/4”) soft-dome tweeter is made of 100% ZYLON®, molded seamlessly from the diaphragm to the surround (edge). Since the woven material for the diaphragm was specially developed for the tweeter, differing from the mid-range in the number of threads and their thickness for the warp and woof, and since the yoke of the magnetic circuit features fully cutting-processed parts (avoiding stress deformities caused by machine pressing) and achieve higher magnetic performance, the system delivers smooth response up to the high-end frequencies, as well as superior S/N performance, high resolution, and increased audio information. The voice coil consists of a square copper wire with sectional shape identical to that of the mid-range and woofer, ensuring maximum efficiency of electro-acoustic conversion, and even finer, more accurate reproduction of audio information through high driver power—as well as achieving reduced transmission loss and lighter weight by directly linking the voice coil to the terminal board instead of another relay wire.
100% ZYLON® 3 cm (1-1/4”) soft-dome tweeter
100% ZYLON® 30 cm (12”) cone woofer—the JA-3132
The JA-3132 30 cm (12”) woofer features a 100% ZYLON® cone without a centre cap. It was designed to offer a wide frequency range unprecedented for a 30 cm (12”) woofer, in order to provide not only a flawless continuity in tone from the woofer to the midrange and to the tweeter as well as acoustic sharpness, both of which was made possible with the use of the identical material for all drivers, but also optimum performance with the higher low-pass crossover frequency of 750 Hz. The woofer's aluminium die-cast frame achieves high rigidity while minimising air resistance at the rear, thanks to the state-of-the-art design based on rigorous FEM analysis of the frame mounted in a prototype enclosure.
100% ZYLON® cone woofer
Suppressing unnecessary acoustic radiation from the back surfaces of the tweeter and the midrange has been a challenge to many speaker engineers. They have taken a variety of approaches to addressing the challenge, including adding a small back chamber packed with sound absorbing materials. However, almost all conventional methods required a large amount of sound-absorbing materials to eliminate strong resonance inside the chamber. With the NS-5000, we have taken a radically different approach; we equipped the backs of the 100% ZYLON® 8 cm (3-1/4”) midrange and 3 cm (1-1/4”) tweeter with the newly developed R.S. Chambers (patent pending). Each of the R.S. Chambers uses two resonance tubes of different lengths to cancel out the resonance peak produced in the main chamber in the middle, thus eliminating the need for sound-absorbing materials inside the chamber that would degrade the sound. The result is that each driver can retain its native flat frequency characteristics and that delicate nuances of music can be reproduced with exceptional detail and articulation.
- Frequency characteristics of R.S. Chamber
- Straight tube filled with sound-absorbing materials
Applying know-how obtained in the development of acoustic conditioning panels, we developed an Acoustic Absorber (patent pending) — a compact J-shaped resonance tube that eliminates standing wave of a specific frequency — and installed two of them in the NS-5000. The speaker's uncomplicated cuboid enclosure helps consolidate internal standing waves at a specific frequency and makes it easy for the Acoustic Absorber to target and suppress that frequency. This eliminates the need for a large amount of sound-absorbing materials inside the enclosure, and helps bring the natural acoustic resonance out of the original music. Acoustic Absorbers also ensure a remarkable continuity in tone between the woofer and the midrange, ensuring that, unlike in a conventional enclosure filled with a substantial amount of sound-absorbing materials, much of the acoustic energy in the high frequency range generated by the woofer is kept intact.
See-through view of two Acoustic Absorbers installed in the enclosure
Acoustic Absorber in action
Without Acoustic Absorber
With Acoustic Absorber
Groundbreaking enclosure design
Aided by laser-scanning measurement and state-of-the-art FEM analysis, we developed a unique enclosure structure that effectively controls “box ringing” to a degree undetectable by human ears. Inside the enclosure, we installed proprietary reinforcing bars designed by simulating with pinpoint precision the way sound from the speaker units is transmitted to and emitted from the six surfaces of the enclosure. These reinforcing bars play an important role in perfectly synchronising the timing of acoustic resonances generated by the enclosure, which helps reproduce the natural acoustic vibrancy with amazing purity and clarity — offering a listener with an unprecedented level of immersive audio experience.
Determining the vibration mode of the enclosure’s surfaces with a laser measuring device