Yamaha Electronics Corporation
FEATURES & TECHNOLOGY
Speaker Technologies
3cm Aluminum-Magnesium Dome Tweeter with DC-Diaphragm (225 PMD Series)
The high-performance tweeter features a dome made of an aluminum-magnesium alloy, with a DC-Diaphragm (integrated diaphragm and voice coil). The tweeter is extremely light to minimize loss yet is highly durable. It is capable of reproduction all the way up to 50kHz Highs are crisp and clear even at high power levels.
A wide range of speakers for every type of home theater system
As high-quality home theaters have become more popular, Yamaha has created the high performane speakers to match. These speakers are characterized by their robustness and dynamism in the reproduction of the current multi-channel sound standard and offer the music lover a pleasant musical sound. Thanks to its own patented technologies, such as Advanced YST or QD Bass, Yamaha subwoofers offer powerful and precise bass reproduction from robust housings with compact dimensions
Advanced YST
Advanced Yamaha Active Servo Technology (Advanced YST) is a unique system in which the speaker and amplifier work together to cancel out impedance so the speaker unit has a perfectly linear motion. Advanced YST helps to ensure the highest levels of sound pressure and overall performance.
Advanced YST II (YST-SW515, YST-SW225)
Advanced Yamaha Active Servo Technology (Advanced YST) uses an Active Servo Processing amplifier circuit to achieve zero impedance so the speaker unit has a more linear motion. In Advanced YST II, an Advanced Negative Impedance Converter enables the speaker cone to be driven with even tighter control. The result is more stable and accurate low range response, as well as higher sound pressure levels, for more natural and energetic bass reproduction.
All-Aluminum Dome Tweeters and Diffusers (HX Series and 515 PMD Series)
Both the shape and material used for dome tweeter diaphragms and diffusers were refined to improve speed and response. 30┬Ám pure aluminum film was formed into a new dome shape and fitted with an all-aluminum diffuser for wide-ranging 50kHz sound reproduction capability.
How Yamaha achieves our ideal sound
The key to achieving the purest, most natural and most pleasing sound is balance. Balance among the above three elements, balance among all the components that make up the speaker, and balance among subjective listening judgments.
How Yamaha achieves our ideal sound
Many cabinets are built and tested for each speaker series.
PMD Cone Woofer Uses Advanced Technology and Materials (515 PMD and 225 PMD Series)
Digital Home Theater Speakers feature a unique Polymer-injected Mica Diaphragm (PMD). The diaphragm is composed of 30% top-quality white Indian Pearl Mica, chosen for the amazing contribution it makes to sound quality. In order to maximize its distinctive qualities, absolutely no coloring is added to the material, and the cone's shape, produced by injection moulding, is a natural catenary curve. Extremely lightweight, it achieves good stiffness along with ideal internal loss and a high modulus of elasticity.
PMD Cone Woofer
QD-Bass Technology
QD-Bass (Quatre Dispersion Bass) technology uses down-firing drivers with square, pyramid-shaped reflective plates to radiate the sound efficiently in four horizontal directions. The reflective plates negate any effects caused by the floor surface and reduce resonance between sound waves reflected from the floor and the unit.
QD-Bass Technology
Testing and More Testing
Yamaha tests speakers in various ways, both before and after production. Each part of the speaker, be it a coil, a capacitor or a cabinet, is selected from among many alternatives, which may be tested for months before a decision is made. In the case of cabinets, for example, we often build 50 or 60 of different woods, sizes, etc. and test each one. In order to test many cabinets with many drivers in many configurations, we begin with computer simulations, then move to actual prototypes for measuring myriad factors, such as the variations of standing waves inside the cabinet. An anechoic chamber is used to obtain precise acoustic data on pre-production models. Even speaker finishes are rigorously tested for durability and how they influence the sound. We have an environmental room where speakers are tested for 500 hours in Amazon rain forest conditions, and five different listening rooms, where speakers are carefully evaluated reproducing a variety of music and movie sources.
Testing and More Testing
A testing room that simulates an actual listening room.
                  The Final Judgment
Speakers undergo harsh environmental testing