BEWITHフラッグシップスピーカーConfidence初期モデル

Bewith’s Essentials of Sound No. 2 – The “Confidence” Flagship Speaker

Bewith is a high-end car audio brand that’s made in Japan. Launched in 2002, it’s a relatively new brand but has already made a significant impact on the car audio world. In just this short span of time, it has established itself as an innovator that has introduced epoch-making products to the Japanese market.

In the last article, we provided an overview of the Bewith brand. Now, we’d like to introduce its flagship “Confidence” speakers and explore more fully the world of car audio.

THE CONTRADICTIONS OF CAR AUDIO AND THE CHALLENGES DEVELOPERS FACE

Speaker development is always the quest for an ideal. In the last article, we explained how basic speaker technology has not changed a great deal over the years and is still relatively “low tech.” There are two massive contradictions that stand in the way of developing the perfect speaker.

The first contradiction involves the raw materials used for the speaker’s diaphragm. The ideal material must be light and solid, and it must have only moderate internal loss. However, “light” and “solid” are two elements that contradict each other. The other factor, that of moderate internal loss, also presents problems.

What “internal loss” means is that there is little reverberation. When something with high internal loss is struck, the vibration will be absorbed by the material. If it’s low, the vibation will cause more reverberation in the material itself. If we use material for a speaker diaphragm that has low internal loss, the diaphragm will vibrate too much, adding excess noise to the sound it produces.

We need material that’s light yet solid, and that has the right level of internal loss. This leads to a continual pursuit of the perfect balance, which can never quite be attained. One material that achieves a near-perfect balance is diamond, but it’s hard to manufacture and the cost is prohibitively high.

As a result, car audio companies spend a great deal of time in development trying to achieve this elusive balance, which is nearly impossible to do.

EQUAL RESPONSE AT ALL FREQUENCIES WITH ONE SPEAKER

Another contradiction that stands in the way involves frequency response. It takes a number of speakers to cover the entire audible frequency range. Ideally, you should have all sound coming from one source. We have what is called a full-range speaker in the world of audio, which produces the sound from only one source. However, it is impossible to cover the entire range of ten audible octaves with only one speaker unit. There are 2-way and 3-way speaker systems that allow you to use different speakers for their strongest parts of the frequency range. With these systems, the efficiency was good but it was difficult to achieve a unified sound.

In speakers, a large aperture is more appropriate for low sounds. A small aperture is better for high sounds. If the size is different, this means that the diaphragm materials must also be different. If you put a number of different speakers with different diaphragm materials together, it’s hard to create the same sound quality among all of the speakers. This is the challenge of creating speaker systems that cover the whole audible frequency range.

There’s also a problem that’s particular to car audio. The interior of a car’s space is limited to a small area. Unlike home audio, the sound bounces around the many different surfaces. This reflected sound can’t be ignored and you therefore need to control the direction of each speaker unit.

HOW BEWITH COMBATS THESE MANY CONTRADICTIONS

In 2002, Bewith managed to put together a mid-woofer and tweeter with the same diaphragm and construction in its Confidence speaker. By offsetting the center of the diaphragm, they created an all-eccentric cone, which allows for the control of the speaker unit’s direction. This allowed developers to solve the two contradictions; the contradiction of materials and the contradiction of creating a unified speaker system.

The key point here is that it uses Bewith’s proprietary PPC (Polar Pattern Control) technology for a directivity control cone to offset the driver. Another feature of PPC technology is that the crossover point between tweeter and mid-woofer is set exceptionally low at 800Hz. Setting the crossover point below the medium-high sound range between the 1st and 5th audible octave in a single unit creates a natural tone quality, especially for solo instruments and voice. It sounds like the performer is right there in the car.

THE PROMISE OF TRUE SOUND

The sound of Confidence has earned it a stellar reputation. It has received rave reviews from well-known car audio magazines. Confidence received first place in Auto Sound’s (Stereo Sound) “The Best Buy 2002-2003” over-100,000 yen speaker category and held first place for the next four years. Sound Up (Kotsu Times) gave it first place for the Front Stage category in its “2003 Component Best Buy.” It held this award for six years until 2008 and in 2009, Bewith gave Confidence a full model change.

Bewith continues to deliver the promise of true sound with its diaphragm materials and construction, and revolutionary all-eccentric cone. They believe that this is the best way to achieve the ideal of perfect speaker sound, presenting musical signals that are natural and faithful to the original sound.

They don’t believe this blindly. Efforts such as collaborative development with Kyushu University researchers deliver the latest scientific data, which Bewith uses to get even closer to that ideal, perfect sound.

(Translated by Greg Scott)