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Subwoofer.
As an indispensable part of the sound system, it is now known by more and more people.
Whether it's bringing life to a nightclub or adding life to your movies, the subwoofer can do a lot.
But as more friends become interested in bass, more questions follow.
What is a subwoofer? When was it invented? What kind of low frequency can be called shocking? Do HI-FI systems also require subwoofers? What the hell is standing wave?
It seems that it is difficult to uniformly answer these questions online.
So the author thought that I should write something about the subwoofer so that everyone can understand it better.
Well then, without further ado, let's officially begin.
Today we will start with the history of the development of the subwoofer and learn a little bit about the big gadget of this fat dun.
What is a subwoofer?
Subwoofer: A speaker in the audio system specifically designed to produce low-frequency (bass) sound.
English name: Subwoofer
Working range: 20-200Hz.
Function: It is used to make up for the diving depth that cannot be reached by the intermediate frequency unit, so as to achieve a more complete and full sound field.
Or we can also understand it literally, a subwoofer is a sound that can make a roar like a cannon.
Whether it's thunder, drumming, or the sound of the earth shaking and the sky cracking, it's what it does best.
It's just that here our domestic interpretation has some discrepancies with the West, and for cultural reasons, the West prefers to use the sea to understand the low-frequency part of the sound.
The 200-20kHz part is air, which is the atmosphere on which human beings live, comfortable and colorful.
Ultrasound above 20kHz is a vacuum outside the universe that cannot be heard, as if it were nothing.
Below 200Hz, the abyss under the ocean is dull and stressful.
And a good subwoofer is like a high-tech submarine, capable of diving to the deepest depths of the Mariana Trench (20Hz or even lower).
So, with this understanding, we can also understand why the subwoofer in English uses a similar word logic to submarine.
I also understand why the description of low frequencies is usually described using words such as "diving" and "depth".
History of the subwoofer
At the beginning of the 20th century, the American film industry developed by leaps and bounds. In order to pursue a better audition effect, producers and theaters are also thinking about how to better restore the extremely low frequency sound.
As a result, an oversized speaker was created and placed in the theater to enhance the performance of the very low frequencies.
It's just that the oversized speaker at this time is only the prototype form of the subwoofer, and there are still many drawbacks of this speaker due to the problem of excessive size and transient performance.
It wasn't until 1941, when Jess tried to make a corner low-frequency loudspeaker, that the value of "Subwoofer" really changed the world's perception of subwoofers.
This is a legendary subwoofer, also known as the "corner woofer".
Its design is inspired by Japanese temples, and Mr. Paul W. Klipsch, the founder of Jashi, discovered a device in the corner of the temple that can transmit sound during a trip to Japan, so he made this bottle subwoofer based on its principle.
And it was with the advent of this subwoofer that the revolution of subwoofers in the audio industry began.
In 1944, Ultra Bluestar developed the 515B subwoofer. This is a loudspeaker designed to be installed on warplanes and aircraft carriers, but because of its excellent durability and sound quality, it was soon used in commercial events such as theaters and theaters.
In 1947, only one year old, JBL successfully developed its own subwoofer loudspeaker and commercialized it in 1962.
JBL 2241
This is what I know, the world's first officially commercialized subwoofer, using an 18-inch vibratory cone, traditional liquid-cooled magnetic circuit and convection heat dissipation design, while using the then quite advanced "ventilation gap cooling" technology.
And, most importantly, it is a conventional armature drive unit based on the elastic drive principle.
In other words, it is different from a subwoofer that uses drumsticks or low-frequency enhancement to release low-frequency frequencies. He is really a speaker unit that can emit its precise sound through analog signals.
So when the JBL 2241 was launched, it beat many products on the market, allowing the world to truly appreciate the charm of low frequency.
Let everyone know that the subwoofer is an absolutely indispensable part of the sound system.
Without it, whatever the sound is, it becomes boring.
Even the major theaters are vying to buy a sizable share.
And it is the success of 2241 that has made JBL a lot of money, and at the same time, it has also allowed major audio manufacturers to smell the market value of subwoofers.
Rapid development
Do you think that with the development of the subwoofer at this point, everything is already over?
Otherwise.
Because the 2241, despite its success, is still relatively traditional in terms of technology.
And because of its price and limitations such as the huge size of the vibrating cone, it is difficult for him to enter thousands of households.
Commercial.
It's just part of the market for subwoofers.
And the household market is the biggest and most fragrant cake.
So in the following decades, many manufacturers racked their brains to develop subwoofer products that were more suitable for home use around their own technology.
However, with the recommendation of the development progress, many problems gradually emerged.
Obviously, the difficulty of developing a subwoofer for a home system is significantly higher than that of a commercial product.
A very key problem is that almost all home listening rooms are not as large as theaters or theaters, and the size of the room does not even have a full low-frequency sound wavelength. (The length of an 80Hz sound wave in air is about 4.3 meters, and 40Hz is a staggering 8.6 meters.) ）
That is to say, if a 40Hz sound is played in a 20-square-meter (length and width set to 4X5 meters) room, then when the sound wave runs halfway, it will touch the wall and reflect, and then contact and superimpose with the second half of the sound wave. Gain is lowered or cancels each other out.
Of course, this is only an explanation of 40HZ sound waves.
But when applied to Hi-Fi systems and AV systems, we will definitely have more low-frequency sound waves, as well as parts above 200Hz until 20KHz.
A complex system of sound waves is constantly swimming through the room, taking into account the phase between the speakers.
The end result is that if an 18-inch theater subwoofer is thrown directly into the room, not only will the low-frequency sound be canceled out, but it will even affect the performance of the mid-high frequency.
A piece of rotten meat spoils a pot of soup.
Besides, in such a small room, it is impossible to stuff such a large subwoofer!
Therefore, even if the cake in the household market is huge, when the major manufacturers decide to open their mouths, they find that this cake does not seem to be as good as imagined.
But just as the so-called eating is not active, there must be something wrong with the mind. (False)
In order to eat the cake of the home market, everyone is riveted and invested in research and development, hoping to solve these problems from multiple perspectives of technology and acoustics.
In the past 30 years, with a large amount of human and financial investment, the audio factory has also gained more understanding of extremely low frequency sound.
Of course, understanding and being able to come up with a decent product are two different things.
Fortunately, with the support of the commercial market, new technologies can be demonstrated in theaters and concert halls, and continuous investment has paid off.
However, because the processing of low frequencies is too difficult, it is difficult for major manufacturers to agree on how to make better bass. So that there are many differences on this road, and various well-known manufacturers are also seeking to solve this problem with their own path.
Passive radiators, high-pass filters, dual voice coil subwoofers, active subwoofers, array subwoofers, these technologies that were familiar until now were invented in that era.
After having so much technical background, major audio companies finally have the confidence to use subwoofers at home.
The JBL L-100 75th Anniversary Remake
The JBL L100, the Sound of the Pulle SDA-2, the Jass KG4, the Bose 901, and the Yamaha NS-10M are all classics of the era.
Subwoofers integrated with mid-high frequencies are ideal for home use, and the technology of guide holes placed on the cabinet to enhance low-frequency performance is gradually maturing.
Most importantly, manufacturers are beginning to realize the role of "stroke" in low-frequency diving.
Even a small unit can emit a more powerful bass than the previous large unit by providing slower vibration and making the entire diaphragm "move" than simply increasing the size of the unit.
Since this time, the era of subwoofers blindly seeking "big" has passed, and 13-inch, 10-inch and even 8-inch subwoofers have appeared.
They are smaller and have better transient response.
The control is more precise, and the standing wave problem is easier to solve.
And the small size of the subwoofer does not take up space, which is more suitable for home environment.
This was a matter of the 90s of the last century, and after more than 40 years of great development, the technology of the subwoofer has approached maturity.
It's just that old problems are solved, and new problems gradually surface.
Controlling the bass standing waves that were scurrying around the room, audiophiles found that what they had bought was nothing more than a "black-and-white TV".
Although the bass is dull, depending on the sound source, each bass also has its own timbre.
Blindly increasing the stroke and intensity, but ignoring the characteristics of the timbre, even if the low frequency is fierce, it will feel boring if you listen to more.
But by the time manufacturers realized this problem, it was too late.
The design of the subwoofer determines that it can only choose between the two, which is also limited by the structure of the unit itself, which still follows the design structure of the traditional horn (the moving coil is bonded to the middle of the diaphragm, and fixed in the magnet with a pluck, and finally the hollow in the center is sealed with a dust cap or guide). Such a design has mechanical defects, and most of the impact requires material to bear. Therefore, in order to resist the damage caused by large strokes, many subwoofer basins use harder carbon fiber or bulletproof cloth. ）。
If you increase the performance of details, then the impact strength of the subwoofer unit will inevitably decrease.
If the power is forced, the subwoofer may become a real cannon. From the muzzle is not only heavy bass, but also maybe bullets or screws.
At this point, everything is back to square one.
Manufacturers in the late 90s looked at their subwoofers, took a deep breath, and decided to start a longer period of development.
What they thought was that maybe it would consume decades as before.
The only consolation is that compared to the 40s, they now have more confidence by relying on the pockets gradually bulging up by existing products.
But no one expected that just when everyone was ready for dozens or hundreds of small goals and finally took a big step forward, a sudden technology suddenly appeared in 2003, which really stumbled on everyone.
W-Cone。
A crystalline diaphragm composed of glass fiber and polyester.
The diaphragm is directly constructed by glass fiber in a crystalline manner on the frame of the polyester structure, forming a uniform arc-shaped mechanical structure like an eggshell, and then fixed with the bracket of W structure, forming a conical structure vibrator very similar to the technology LOGO.
The W-Cone cone has a thin diaphragm that is diametrically opposed to other subwoofer cone materials, but even if it is thin, its strength and stiffness are several times higher than that of a metal cone of the same thickness.
Coupled with the absence of adhesion in the structure, the W-Cone vibrating cone has a strong mechanical dispersion ability. At the same time, the slim structure is also excellent in sensitivity and detail.
In other words, W-Cone is exactly what major manufacturers hope to develop in the next decade or two.
It's not that they don't think of new materials and new constructions.
But materials science is such a weird thing, and a lot of times you have to be lucky.
Here is a little mention of the company that owns the technology, JL Audio.
Although the company was founded in the era of subwoofer development, when it was founded in 1975, it was enthusiastic about the production and production of car tuning units.
In 1978, JL Audio released their first amplifier, one of the smallest and lightest on the market at the time, and quickly won over consumers.
In 1985, JL Audio introduced the world's first high-power, ultra-small, high-efficiency car audio amplifier, which won widespread acclaim for sound quality and reliability.
Subsequently, JL's units became famous in the car audio and yacht audio world, and orders followed.
As for W-Cone?
The original intention of JL to design it is actually more to enhance the waterproofness of yacht audio.
The dust cap of traditional audio is easily eroded by sea salt, and only the unit that can be perfectly integrated with the diaphragm is a more brilliant product.
But the results can be imagined:
The big factories can't ask for it.
JL WAS ON THE RIGHT SIDE.
I never thought that the ultra-high strength of the W-Cone's cone makes it very suitable for subwoofer unit production.
With just an 8-inch unit, the stroke can reach a staggering 9 cm.
Moreover, the thin glass fiber composite film can also more accurately restore more low-frequency sound waves should have the timbre.
It's a natural thing.
If the structure of the traditional unit is used, under such a large elastic action, the dust cap will have to fly out after a few rounds.
Angry or not?
A subwoofer unit with a W-Cone vibrating cone was used
It should be...
But with the advent of W-Cone technology, more manufacturers have also clarified the direction.
In short, there will be no more detours than in the 70s.
It's just that it's not easy to find a material similar to W-cone.
Today, there are not many successful cases.
As far as the author has found, only Hertz acoustics' V-Cone cone has touched the threshold of W-cone from the data, and has produced several V-Cone subwoofers that are also very good.
A subwoofer unit with the V-Cone cone was used
Today, in 2023, many audio factories have given up the competition for the subwoofer track.
Although the rest are still trying to find new materials to replace the current subwoofer structural design, traditional technology is still improving and innovating.
It turns out that even with what was used before, it is not completely impossible to restore richer low-frequency sounds.
With the continuous investment in more professional tuning and research and development, SVS, REL, B&W, Jas, Pule Sound, KEF, Devaniti, Bridon, Williton these nine audio manufacturers have also merged with JL and are known as the world's top ten subwoofer experts.
But what exactly will the future hold?
The author, I don't know.
Because what we are talking about today is, after all, just history.
As for the other questions, follow me and we'll continue in the next article.