Introduction
No matter what kind of amp you use, it is the speaker that actually produces the sound, and it is the closest sound outlet to our ears. It may be an exaggeration to say that "no Marshall or Fender sound is complete without speakers," but there is no doubt that speakers play an important role in the guitar sound. So, in this article, I would like to focus on speakers in guitar amplifiers.
Compared to electric guitars, loudspeakers have a much older history. The world's first public use of loudspeakers is said to have occurred in 1919, when President Wilson gave a speech in San Diego. Later, with the explosive success of the "talkie" sound film, various types of loudspeakers for public speaking were developed, mainly for movie theaters. Eventually, with the introduction of the electric guitar in the 1950s and the rock music movement of the 1960s, speakers for musical instruments followed in rapid succession.
Speakers are part of the instrument?
You may have often seen them in guitar amp catalogs, with catch phrases such as "equipped with selection speakers. There are so many myths and rumors about guitar amp speakers that it is easy to see that many people are very particular about the speakers in their amps.
For example, does a person who plays guitar and sings care about the PA speaker unit? Or a vocalist who says, "I only sing with JBLs!" But if we are talking about guitar amplifiers, it is a bit of a stretch. But when it comes to guitar amplifiers, they suddenly become very particular, saying, "It has to be a Greenback," or "It has to be a Jensen. This is because the speaker used in a guitar amp is as important a factor as the amp itself, and is not just a place to produce sound, but a part of the instrument that creates the sound. Perhaps the only places where speakers are given this much importance, to a sort of mythical degree, are in the profound world of audio and guitar amplifiers.
Many of you may have connected distortion or other effectors to your guitar and hooked it up to your home stereo or other device to create sound. The result may have been a jarring sound that didn't sound very much like a guitar sound. The same is true when you connect the line out of a head such as a Marshall to a mixer. In the past, there were many products such as speaker simulators, and it was necessary to process the sound to get a speaker-like sound even when using a line out, and even in recent digital modeling, the sound including the sound from the speaker is sampled to create the sound. It is no exaggeration to say that the full, thick, and three-dimensional sound characteristic of guitar amps is produced by speakers.
Today, few guitar amp manufacturers manufacture their own speakers, and many of them use speakers made by well-known speaker manufacturers. This means that the compatibility between the amp and the speakers, or rather, the oddity of matching the amp and the speakers, makes the sound even more unique. Now, let's take a trip in search of speakers, looking at actual examples such as "Fender and Jensen, Marshall and Celestion. Let's take a little trip through history.
It all started with Jensen!
Peter Jensen, the father of the American sound
Jensen speakers are especially familiar from Fender amps of the Tweed era. This is the beginning of not only the American sound but also the world's speakers.
Peter Jensen, the founder of Jensen, was born in Denmark in 1886 and worked as a telephone and radio engineer from a young age. He eventually moved to the United States at the age of 23, where he met an engineer named Edward Pridham, and the two, attracted by each other's talents, established a small workshop in California and began developing radio transmitters and other products. In 1915, Jensen and Pridham invented the world's first loudspeaker using a voice coil. This was such a major event that it could be said to be the beginning of all subsequent sound equipment. The Magnavox loudspeaker was named the "Magnavox" and they founded the Magnavox Corporation in San Francisco, which became widely known throughout the United States for civilian and military applications. Jensen left Magnavox in 1925 and moved to Chicago, where he founded Jensen Speakers the following year in 1927. This was the birth of the legendary Jensen speaker.
Magnavox vacuum tube package.
It is labeled "for radio/TV," which is a reminder of the world of the time.
Jensen moved to Chicago and began developing loudspeakers. It was only natural that Leo Fender, who was developing guitar amplifiers in the 1940s, would encounter Jensen loudspeakers. Jensen loudspeakers became an integral part of the Fender Tweed sound in the 1950s.
Fender amps with Jensen speakers in the early 50's
As rock music became popular in the 1960s, the supply of guitar amplifiers increased, and manufacturers such as Ampeg and Gibson began producing guitar amplifiers. Naturally, Jensen speakers were used.
The Jensen logo can be seen peeking out from the back of a 60's Ampeg Blue Diamond.
The End of Jensen
Thus began an era of Jensen loudspeakers. As the scene expanded, many manufacturers naturally entered the loudspeaker market, and many models were created based on Jensen's sound, including Oxford, Utah, and even CTS (Chicago Telephone Supply), which was joined by former Magnavox engineer Bob Gault. CTS (Chicago Telephone Supply), which included Bob Gault, a former Magnavox engineer, and many other manufacturers modeled their loudspeakers after Jensen's sound.
In the early 1960s, Fender amps also began to use Oxford speakers. There are several theories as to why this happened. Some say that Leo Fender made a request to Jensen, but Jensen did not respond to it. Whether the request was for sound or cost is a mystery now, but considering that Fender amplifiers have been equipped with Reverb since 1963, it is likely that there was a matching factor with the development of the Reverb. As a result, Oxford became the core of the Blackface Reverb sound in the 1960s.
'64 Fender Princeton Reverb equipped with Oxford speakers
Peter Jensen is said to have passed away in 1961. With the loss of Peter Jensen, Jensen gradually withdrew from the loudspeaker market, and in the late 1960s, the company stopped making loudspeakers. In the late 1960s, the Jensen speaker became an enduring legend.
(However, the desire for the Jensen sound has continued to grow, and today, SICA Altoparlanti in Italy has acquired the license and produces models under the Jensen name, using the same manufacturing process as at that time.)
A '66 Jensen with the Fender logo; this design could be seen as late as the late 60s.
The reissued Jensen from the 90's onward is labeled "MADE IN ITALY".
American standard EMINENCE after Jensen
Around the time Jensen disappeared from the market, EMINENCE appeared on the scene as if to take over. As mentioned above, Bob Gault, an engineer at Magnavox, which Peter Jensen had founded, and who had also been involved in speaker design at CTS, founded EMINENCE in 1966 and began manufacturing speakers. In the beginning, the company was commissioned by Ampeg to manufacture about 3 speakers a day, but with the spirit of the Jensen lineage and abundant technical expertise, many American brands, including Peavey, demanded the company's reliable tone, and today EMINENCE is the largest manufacturer of loudspeakers in the United States, producing 10,000 loudspeakers in one day. Today, the company is the largest speaker manufacturer in the United States, producing 10,000 loudspeakers a day.
In Fender amplifiers, Peavey has replaced Oxford, whose quality declined in the 70's, and is now used in almost all Fender models. You can also find them in almost every manufacturer, from long-time friends Ampeg and Peavey, to newer, leading brands such as Soldano, VHT, Rocktron, and Egnator, and bass amps from Hartke, Gallien Krueger, and others.
The Tragic Life of Another Hero, "JBL"
We have looked at the history of American speakers from Jensen to the present. In this way, it can be said that the history of American speakers is that many manufacturers have followed the legendary sound of Peter L. Jensen, even though the brands are different.
However, there is another genius in the history of American speakers who should not be forgotten. He was also dedicated to sound. James B. Lansing, the tragic genius who pursued sound to the end of his life.
James B. Lansing, the founder of JBL, was born in 1902, 16 years younger than Peter Jensen. Like Peter Jensen, James B. Lansing was interested in electrical machinery from an early age, and spent his childhood taking things apart and building things. He was so enthusiastic that he was known as a boy prodigy in his neighborhood.
When he came of age, he chose to become an engineer at a radio station. However, he became passionate about making loudspeakers, as there were no loudspeakers that could play music satisfactorily at that time. In 1927, he established his own company, Lansing Manufacturing Co. in California and began manufacturing speakers. Coincidentally, this was the same year that Peter Jensen left Magnavox to found the Jensen Company. With the talkie film boom, Lansing's loudspeakers were highly acclaimed, winning an Academy Award in the technical category for their sound quality, and were sought after by many movie theaters. However, Lansing's insatiable pursuit of sound was not good for business, and the company gradually fell on hard times.
At the same time, Western Electric, one of the leading sound manufacturers in the U.S., established All Technical Services to provide maintenance services for audio equipment, mainly for movie theaters. All Technical Services recognized Lansing's high level of technical expertise and purchased Lansing Manufacturing Co. in 1941, forming a company called Altec Lansing, which became James B. Lansing Lansing. James B. Lansing became vice president of the company and was responsible for speaker development. The technology that James B. Lansing brought to Altec Lansing was at the core of what would later become Altec's legendary loudspeaker production. The technology that Lansing brought to the company at this time is said to be at the core of Altec's later reputation as a legendary loudspeaker manufacturer.
In 1946, James B. Lansing left Altec to found James B. Lansing (JBL), a company that would produce loudspeakers with the sound he wanted. Coincidentally, JBL was born the same year that the Fender amplifier was introduced to the world. The following year, in 1947, JBL produced the D130, which is considered to be an eternal classic. Later, as the D130F, it became a masterpiece of Fender amplifiers, and it also boasted a great reputation. Unfortunately, this was James B. Lansing's last work.
Although James B. Lansing had established JBL as an independent company from Altec to pursue his own sound, the company was still in a difficult business situation. Perhaps he had been given two gifts from heaven, or perhaps his luck had deserted him. Or perhaps he was jealous of other gods because he loved "sound" so much. In 1949, James B. Lansing finally chose to take his own life. He was 47 years old.
But even so, JBL did not die. James B. Lansing's insatiable pursuit of sound was carried on by the many engineers who admired him, and the company got back on track and the JBL name regained its luster. While many acoustic speakers of the era were produced, the D130F, a musical instrument version of the famous D130, was used as an option for Fender amplifiers in the 1960s, attracting many players with its beautiful overtones and rich sound. It was also the legendary one that Mesa/Boogie's founder Randall Smith said of Santana, "Really Boogie! JBL was also used in the legendary case where Mesa/Boogie's founder, Randall Smith, said to Santana, "Really Boogie! Today, JBL is still the first name that comes to mind when one thinks of acoustic loudspeakers, and has been so successful that even James B. Lansing himself would not have expected it.
D-110F, a 10-inch version of James B. Lansing's famous D-130 for musical instruments
There have already been so many compliments on the sound of JBL speakers from all over the world that I feel it is too late for me to say anything, but if I were to put it simply, I would say that they are "just right for listening to music". It is not the "sound of good speakers," but the feeling of listening to "good music," forgetting about such things. When you notice it, you are intoxicated by the music that is playing, and I wonder if that is the charm of JBL speakers (especially older models).
The K series, also using alnico magnets, followed in the footsteps of the D series.
Pictured is the 12-inch K120.
The E series changed from alnico to ferrite magnets.
This is the E140 for 15-inch bass.
Altec Lansing, on the other hand, has continued to be a top brand of acoustic speakers, and in the 1970s developed the 417-8HII, an epoch-making speaker for musical instruments, which was used as the mainstay of the Mesa/Boogie MK-I and MK-II, and is also known as Randy Rhodes's favorite speaker. Randy Rhodes' favorite speaker. In the late 1990s, Altec became part of Electro Voice, and continues to be at the forefront of the audio industry.
Mesa/Boogie MK-I from the 1970s with Altec's epoch-making 417-8H II
Electro Voice, which ruled Altec, was established in 1927 like Jensen and Lansing Manufacturing Co. Lansing has been selling loudspeakers since 1949, the year James B. Lansing passed away. The company is well known for its Mesa/Boogie MK-III guitar amplifiers, and is also extremely popular as a bass speaker. Today, the brand is still a good rival to JBL and is often seen in various venues as sound equipment.
MK-I hardwood enclosure from the 1970s showing Electro Voice in use
Resonance - A History of American Speakers
We have run through the history of American speaker brands, and when we look at it this way, we cannot help but feel a sense of luck, so much so that the expression "strangely enough" has been used many times. Many brands have disappeared in the history. And the brands that have inherited them and continue to produce them at this very moment. I have the impression that their passion for sound resonates with each other to create this history.
Celestion, the pride of the British sky speaker
Meanwhile, across the sea in the United Kingdom, another great legend was born. Celestion was founded in 1924. Celestion was founded in 1924, three years before Jensen, Lansing Manufacturing Co. and Electro Voice in the U.S., making it the oldest speaker manufacturer still in production in the world. Celestion was founded by Cyril French, who built a small speaker factory in Hampton Witch, Kingston, Surrey, a suburb of London that was the setting for the Harry Potter movie. He began building new loudspeakers with the help of an engineer named Eric Mackintosh, who was already a highly skilled loudspeaker maker at the time. The name Celestion is said to have come from the word "celestial," meaning "heavenly," or "sacred," and was given by Cyril French's brother, Ralph, who wanted the sound to soar "high in the sky, Ralph, brother of Cyril French.
At the time, Celestion was manufacturing phonographs in addition to loudspeakers, but the British Broadcasting Corporation (BBC) began broadcasting in 1922, and the radio boom helped spread the sound quality of Celestion's loudspeakers over the airwaves throughout the United Kingdom. The sound quality of Celestion loudspeakers spread across the airwaves throughout the United Kingdom.
In the late 1920s, Rola, a speaker manufacturer in Cleveland, Ohio, USA, built an English factory in Thomas Ditton, just a few kilometers southwest of Celestion, and began manufacturing speakers. In 1942, when World War II brought increased military needs, Rola moved its entire loudspeaker manufacturing division to the UK plant, and the mainland US plant focused on aircraft lighting and other military applications. The British Rola factory, empowered by the consolidation of the speaker division, absorbed Celestion in 1947, after the war. In 1949, Rola Celestion acquired Truvox, a Wembley-based manufacturer of audio equipment and speakers. Truvox, a manufacturer of audio equipment and loudspeakers in Wembley. Among the engineers who joined the company as a result of this merger was Les Ward. He would go on to develop the legendary G12 loudspeaker that would make the Celestion name world famous. The encounter between Les Ward and Celestion was to change the course of history. Just over the ocean, the American genius James B. Lansing ended his own life.
The late 1950s marked a turning point for Rola Celestion. Les Ward, already a key figure at Rola Celestion, received a large order from his old friend Dick Denny of Jenning Musical Industries for a speaker for a guitar amplifier. In 1957, a guitar amplifier equipped with this speaker was introduced to the world as the VOX AC15. In the 1960's, the Beatles traveled the world and put the VOX and Celestion name on the map.
VOX and Celestion
The success of VOX amplifiers brought Rola Clestion speakers to the attention of guitar amp manufacturers. One of the first to approach the company was Jim Marshall, and in 1962, five years after the introduction of the VOX AC15, the first Marshall amp with Celestion speakers was launched into the world.
Rola G12 with THAMES DITTON SURREY ENGLAND
The Celestion loudspeaker, which was so successful with VOX and Marshall, has become a symbol of the British sound and is still used by manufacturers and players all over the world today. In the United States, Celestion loudspeakers are preferred by many top brands, including Mesa/Boogie, Matchlass, and Bogner, and are often used in models made in Japan.
The G12's worldwide success led Rola Celestion to expand its factory, and in 1970 it established a huge factory dedicated to the G12 in Ipswich, Suffolk, northeast of London. In 1975, the entire operation, including the headquarters, was concentrated there, and Celestion speakers continue to be produced at the Ipswich plant today.
The G12 Greenback, commonly known as the "Pre-Roller," before the move in 1970.
This is a G12 greenback, commonly known as a "pre-roller," before the move in 1970, and marked THAMES DITTON SURREY.
This is a recent greenback labeled IPSWICH, ENGLAND.
How to identify the speaker
Most speakers have a label on the back with the manufacturer's name and other information. However, Fender amplifiers, for example, have a label that reads "Fender" and does not indicate which manufacturer's speaker it is from. Also, if the speaker is old and the label is illegible, you can check the "factory code" to find out when and where the speaker was made if it is an American speaker.
The Fender logo is conspicuous, but Fender itself does not make speakers.
Printed on the edge of this speaker is the factory code
The factory code is usually a six-digit number.
The first three digits from the left indicate the manufacturer (220 is Jensen), the next is the first place of the year (7 for 1957), and the last two digits indicate the week of the year (49 for 49th week → from around December 2nd to 9th). The fourth number, which corresponds to the year of manufacture, indicates only the first place of the year, so it is not possible to determine whether the year is 57, 67, or 77 for 7, for example, from the notation alone. Therefore, we have to make a comprehensive judgment based on the specifications of the speaker and the period during which it was manufactured.
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Factory code for this speaker can be found here.
In recent years, Eminence has been denoted by 67- (8-digit number) and the first two digits after 67- indicate the Western calendar year.
This is the year 99.
What about this speaker mounted on a tweed amplifier?
Here's the factory code: 1960 Oxford.
How to determine the age of the selection speaker
Since Celestion is a British speaker, it is marked differently, with a two-digit number and a two-digit alphabet; the second digit indicates the date, the first alphabet indicates the month of manufacture, and the second alphabet indicates the year of manufacture.
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Example: In this case B=February, L=1978, 9=date, indicating manufacture on February 9, 1978.
The T1871 shown below is the version number of the model, called the T number, which controls the specifications of the voice coil, cone paper, etc. The "T" at the top of the number is the version number of the model, which controls the specifications of the voice coil, cone paper, etc. The "T" at the beginning is said to have been given by designer Les Ward in honor of Truvox, which was acquired by Celestion.
Challenging Speaker Replacement / Allowable Input and Impedance
Replacing speakers does not require special skills or tools. Depending on the shape of the wiring, many speakers can be replaced without the need for soldering, and basically all you need is a screwdriver and a wrench (or pliers).
(For some models, such as combo amplifiers, the speaker cannot be removed without disassembling the amplifier. For such models, we recommend that you ask a specialized store to do the work.)
Remove this nut, and the speaker can be removed.
This type of connector can be easily removed without soldering.
Be careful not to mistake the plus and minus!
Allowable Input and Impedance
The first step in replacing speakers is to decide what you want to change to. We hope you now understand the historical flow of each brand. We hope you can also refer to the sound image of each model on the product pages of our website.
When deciding on a replacement speaker, it is also necessary to determine the allowable input and impedance. The allowable input is the maximum output (watts) that the speaker can accept, and using more than that will damage the speaker and possibly the amplifier itself. The basic rule of thumb is to select an acceptable input that is greater than or equal to the output watts of the amplifier. If multiple speakers are used, the total allowable input for each speaker is the total allowable input for the entire system.
For example, a single speaker with 30 watts of allowable input cannot be used in a 50-watt amplifier, but two speakers with a total of 60 watts of allowable input can be used in a 50-watt amplifier.
Next, let's look at impedance. A speaker operates by receiving current from the amplifier's output transformer, and impedance is the resistance value required to operate efficiently with respect to the amount of current it receives. As with the allowable input, the speaker cannot be used with an impedance smaller than the output impedance (amount of current) of the amplifier. This too can cause damage, such as breakage. Also, especially in the case of tube amplifiers, if the impedance is larger than the output impedance of the amplifier, it will not sound efficient, and the response may be reduced or the sound may sound distant. It is best to choose an impedance that is appropriate for the output impedance of the amplifier. For example, if the output impedance of the amplifier is 8 ohms, use an 8 ohm one. If the output impedance of the amplifier can be switched between 8 and 16 ohms, it is better to use the maximum impedance (16 ohms in this case), as this will increase the amount of current output and allow the amplifier to output its power in the most efficient manner. (Although there is a subterfuge of using it at 4 ohms/4 ohms on a dare and substituting it for an attenuator when a small venue cannot produce a loud sound, such as with a marshal.) In many cases, transistor amplifiers are marked with a minimum number of ohms, so you can use them as long as the impedance is higher than that.
When multiple speakers are used, the total impedance is the sum of the impedances when connected in series, or when connected in parallel, the total impedance is the sum of the impedances divided by the number of speakers.
Do not use speakers with different impedances at the same time, as this can cause problems and poor sound balance.
Above figure (series): 8Ω+8Ω=16Ω
Bottom (parallel): 8Ω ÷ 2 (number of speakers) = 4Ω
(The impedance in parallel can also be calculated by Ohm's law: 1/A+1/B=1/n)
About speaker repair
There are few parts of a speaker that can be repaired without special skills, and if the speaker has been blown out or the cone paper has been torn, the entire speaker will basically have to be replaced. If the speaker has been damaged, it is usually easier and less expensive to replace the speaker than to repair it. However, if there is no vintage equivalent available and the speaker must sound the same, it is possible to repair the speaker by re-covering the cone paper or repairing the voice coil.
Maintenance that anyone can do
As you can see, there are very few parts of a speaker that can be maintained, but here are some simple checkpoints that can be done, though not so much maintenance. One 12-inch speaker for a guitar amplifier usually weighs more than 3 kg, and some are nearly 10 kg. Since these speakers vibrate violently at high volume, the vibration will naturally loosen the screws that hold the speakers in place. This means that the vibration of the speaker is not directly reflected in the cabinet, and depending on how loose the screws are, the sound will be loose. For example, if you open a Marshall cabinet that has been used for five or six years, you will find that most of the speakers inside are loose. By simply tightening them back up, the sound will suddenly become much tighter, so if you feel that the sound has lost some of its edge, you should check it out. It depends on the situation, but the change can be surprising, so if you are using it frequently at high volume, it is a good idea to check it regularly for looseness.
(Sometimes, when I see an old amp in a practice studio, I get the urge to tighten the speaker screws. (Sometimes I encounter old amps in practice studios that sound so good that I get the urge to say, "Oh, I want to tighten the speaker screws!) (Sometimes I come across old amps in practice studios that make me feel the urge to tighten the speaker screws....)
Just by tightening these screws, the sound becomes tighter.
What is a speaker?
A device that transmits sound through air vibrations by causing the diaphragm to vibrate when an electric current is applied to the coil. This is the definition of a speaker. In other words, we are listening to the air vibrations delivered by a speaker. Sound is air. I don't usually think of it that way, but there was an episode that made me feel that way, and I would like to share it with you at the end of this article.
Some years ago, when I went to the U.S., I was shuddered by the music coming from the ceiling in the bus. It was a famous song by Eric Clapton, and although I am not an avid fan, I had heard it many times on CDs at home, on the radio, and as background music in stores I stopped at, and with all due respect, I was tired of hearing it. I wondered why it was such a horribly beautiful guitar sound. I looked at it and saw that it was coming from a tiny speaker embedded in the ceiling of a cheaply built bus, and in mono. It was not an acoustically favorable environment, but I could hear frequencies I had never heard before, and if sound had a color, I could see it in a vividly different color. It was then that I realized for the first time that "it was different from what I hear in the Japanese air.
Since then, I have come to realize that if you are a little careful, you can hear the sound of the weather on a sunny day and the sound of rain on a rainy day. When I listen to records with this sense, I realize that records from the 60s have the sound of the air of the 60s, and records from the 70s also have the sound of the air of that time. (What about the more recent line recordings?) After all this talk about speakers, it would be a bit of a stretch to say "air" at the end (what was that all about before?), but I would like to conclude this episode by reminding you that we are listening to the sound of air through a variety of speakers. I would like to conclude with this episode.
I want to cherish the air.