Introduction
Ultimately, it is the speaker that produces the sound from any amplifier, and it can be said to be the sound outlet closest to our ears. While it might be an overstatement to say, “Neither the Marshall sound nor the Fender sound would exist without speakers,” there is no doubt that speakers play a crucial role in guitar sound. So, in this article, I’d like to shine a spotlight on speakers in guitar amplifiers.
Compared to the electric guitar, the history of speakers dates back quite a long way. It is said that the world’s first public use of a loudspeaker occurred in 1919, during a speech by U.S. President Wilson in San Diego.Subsequently, following the explosive success of “talkies,” various public address speakers were developed, primarily for use in movie theaters. Eventually, with the advent of the electric guitar in the 1950s and the rise of the rock music movement in the 1960s, speakers designed specifically for musical instruments began to appear one after another.
Are Speakers Part of a Musical Instrument?
You’ve probably seen catchphrases like “featuring Celestion speakers” quite often in guitar amp catalogs. With opinions ranging from “Fender sounds best with Jensen” to “Marshall is only worth it with Celestion,” and with so many myths and rumors circulating, it’s clear that many people have strong preferences when it comes to guitar amp speakers.
For example, would a singer who plays guitar while singing really care about the speaker units in a PA system? Is there a vocalist who says, “I’ll only sing through JBLs!”? Yet, when it comes to guitar amps, it’s curious how people suddenly become particular, insisting, “It has to be a Greenback” or “It has to be a Jensen.” This is because, in guitar amps, the speakers play a role just as important as the amp itself; they aren’t merely “a place to produce sound,” but rather “a part of the instrument that shapes the sound.”The world of high-end audio and guitar amps may be the only places where speakers are held in such high regard—almost to the point of being mythical.
I imagine many of you have tried plugging a guitar with distortion or other Effectors into your home stereo system. The result was probably a gritty, scratchy sound that didn’t sound anything like a real guitar, right?The same applies when connecting the line out of a head—such as a Marshall—to a mixer. In the past, there were many products like speaker simulators, and even when using a line connection, it was necessary to process the sound to achieve a speaker-like tone; even with recent digital modeling, sounds are crafted by sampling the output from the speaker itself. Thus, it’s no exaggeration to say that the rich, full-bodied, and three-dimensional sound unique to guitar amps is created by the speaker.
Today, very few guitar amp manufacturers produce their own speakers; most use speakers from well-known speaker manufacturers. As a result, the synergy—or rather, the subtle interplay—between the amp and the speaker further enhances the uniqueness of that sound. So, let’s embark on a journey to find the perfect speaker by looking at specific examples like “Fender and Jensen” or “Marshall and Celestion.” Let’s take a brief stroll through history.
Did It All Start with Jensen!?
Peter Jensen: The Father of the American Sound
Jensen speakers are particularly familiar from Fender amps of the Tweed era. It’s fair to say that these speakers marked the beginning not only of the American sound but of the global speaker industry as well.
Surprisingly, Peter Jensen, the founder of Jensen, was originally from Denmark. Born in 1886, he worked as a telephone and radio technician from a young age. Eventually, at the age of 23, he moved to the United States, where he met an engineer named Edward Pridham. Drawn to each other’s talents, the two established a small workshop in California and began developing radio transmitters and other equipment.Then, in 1915, Jensen and Pridham invented the world’s first loudspeaker to use a voice coil. This was such a monumental event that it could be said to mark the beginning of all subsequent audio equipment. The invented speaker was named “Magnavox,” and the two subsequently founded Magnavox Corporation in San Francisco.Magnavox speakers became widely known throughout the United States for both civilian and military use. In 1925, Jensen left Magnavox, moved to Chicago, and founded Jensen Corporation two years later, in 1927. This marked the birth of the legendary Jensen speakers.
Magnavox vacuum tube packaging.
Labeled “for radio/TV,” it offers a glimpse into the social climate of the time.
After moving to Chicago, Jensen set out to develop loudspeakers. In this way, he made a name for himself in America as a pioneer of loudspeakers. It was perhaps only natural that Leo Fender, who was developing guitar amplifiers in the 1940s, would come across Jensen’s speakers. Thus, Jensen speakers became indispensable to the Fender Tweed sound of the 1950s.
Fender amplifiers from the early 1950s featuring Jensen speakers
Then, as rock music began to gain popularity in the 1960s, the supply of guitar amplifiers increased, and manufacturers such as Ampeg and Gibson also began producing them. Naturally, Jensen speakers were used in these amplifiers.
The Jensen logo is visible on the back of a 1960s Ampeg Blue Diamond.
The End of Jensen
In this way, Jensen speakers defined an era. As the scene expanded, it was only natural that many manufacturers entered the loudspeaker market, and numerous models were created that drew inspiration from the Jensen sound. Many manufacturers—including Oxford, Utah, and CTS (Chicago Telephone Supply), which was joined by Bob Gault, a former Magnavox engineer—began producing speakers modeled after Jensen.
Then, starting in the early 1960s, Fender amplifiers also began adopting Oxford speakers. There are several theories regarding this, and rumors persist that Leo Fender made some kind of request to Jensen, but Jensen declined.Whether that request was related to sound or cost remains a mystery today, but considering that Fender amplifiers began featuring reverb in 1963, it’s possible that compatibility with that development was also a factor. As a result, Oxford speakers became the cornerstone of the Blackface Reverb sound of the 1960s.
A 1964 Fender Princeton Reverb equipped with Oxford speakers
It is said that Peter Jensen passed away in 1961. He dedicated his life to sound.Having lost Peter Jensen, did Jensen lose its sense of direction? The company gradually withdrew from the speaker market and ceased speaker production in the late 1960s. Thus, Jensen speakers became an eternal legend.
(However, driven by the continued demand for the Jensen sound, the Italian company SICA Altoparlanti has since obtained a license, and models made using the same manufacturing methods as back then are now produced under the Jensen name.)
A 1966 Jensen bearing the Fender logo. This design was common until around the late 1960s.
Reissue Jensen models from the 1990s onward are marked “MADE IN ITALY.”
The American Standard Eminence, the Successor to Jensen
Around the same time Jensen was disappearing from the market, Eminence emerged as if to take its place. As mentioned earlier, Bob Gault—a former Magnavox engineer who had worked on speaker designs at CTS and was once part of the team that Peter Jensen founded—established Eminence in 1966 and began manufacturing speakers.Initially, the company reportedly produced about three speakers a day on commission for Ampeg. However, supported by the spirit inherited from Jensen and its rich technical expertise, Eminence became sought after by many American brands—including Peavey—for its reliable tone. Today, it has become the largest speaker manufacturer in the United States, producing 10,000 speakers a day.
In Fender amplifiers, Jensen speakers replaced the Oxford speakers—whose quality had declined in the 1970s—and are now used in most models. Furthermore, Jensen speakers can be found in products from nearly every manufacturer, including long-time partners like Ampeg and Peavey, as well as newer leading brands such as Soldano, VHT, Rocktron, and Egnator, and even Bass amplifiers from companies like Hartke and Gallien-Krueger.
The Tragic Life of Another Hero: “JBL”
We’ve traced the lineage of American speakers from Jensen to the present day. Looking at it this way, it seems that—despite the different brands—the history of American speakers is defined by the fact that many manufacturers have continued to pursue Peter L. Jensen’s legendary sound.
However, there is another genius in the history of American speakers who must not be forgotten. He, too, dedicated his life to sound. He is James B. Lansing, a tragic genius who pursued sound until his downfall.
James B. Lansing, the founder of JBL as you may know, was born in 1902. This makes him 16 years younger than Peter Jensen. Like many others, James B. Lansing developed an interest in electrical machinery from an early age and spent his boyhood engrossed in taking things apart and building them.His passion was so intense that he became known in the neighborhood as a child prodigy.
As an adult, he chose to pursue a career as a radio station engineer. However, since there were no speakers at the time capable of reproducing music satisfactorily, he became increasingly passionate about building them. Then, in 1927, he founded Lansing Manufacturing Co. in California and began manufacturing speakers.Coincidentally, this was the same year that Peter Jensen left Magnavox to found Jensen. It was also the height of the talkie boom. Lansing’s speakers were a huge hit, winning an Academy Award for Technical Achievement for their superior sound quality, and were in high demand from many movie theaters. However, perhaps his relentless pursuit of sound quality backfired, as the company struggled financially and gradually fell into dire straits.
Around that same time, Western Electric—a major American audio equipment manufacturer—had established All Technical Services (Altec Services) primarily to handle the maintenance of audio systems in movie theaters and other venues. All Technical Services recognized the high technical capabilities of the struggling Lansing company, acquired Lansing Manufacturing Co. in 1941, and established the company Altec Lansing.James B. Lansing then took on the role of vice president, overseeing speaker development. This marked the birth of Altec speakers, which would go on to be renowned as iconic models. James B. Lansing’s talent was fully realized at Altec Lansing, and numerous legendary speakers were produced during this period. It is said that the technology Lansing brought to the company at that time formed the core of what later earned Altec its reputation as a legendary speaker manufacturer.
Then, in 1946, James B. Lansing left Altec to create speakers that would produce the sound he envisioned, founding James B. Lansing (JBL). Coincidentally, JBL was born in the same year that Fender amplifiers made their global debut. The following year, in 1947, he produced the D130, considered a timeless classic.Later known as the D130F, it is a masterpiece that enjoys immense acclaim even among Fender amplifiers. Unfortunately, however, this became James B. Lansing’s final work.
Although he had left Altec to pursue his own sound and founded JBL, the company still faced severe financial difficulties.Perhaps, as the saying goes, “God does not give two gifts,” or perhaps he had simply been abandoned by luck. Or maybe his intense love for “sound” aroused the jealousy of some other deity. Gradually burdened by massive debts and having reached a dead end, James B. Lansing ultimately chose to take his own life in 1949. He was 47 years old.
Yet JBL did not die with him. James B. Lansing’s way of life—marked by an insatiable pursuit of sound—was carried on by the many engineers who admired him, and the company got back on track, with the JBL name regaining its luster.While numerous iconic speakers that defined their eras were being produced, the 1960s saw the D130F—an instrument-specific version of the legendary D130—used as an option for Fender amplifiers, captivating many players with its beautiful harmonics and rich tone.It is also well known that JBL was used in the legendary incident where Mesa/Boogie founder Randall Smith made Santana exclaim, “Really Boogie!!” And even today, JBL remains a premier brand—one whose name is the first to come to mind when people think of audio speakers—achieving a level of success that James B. Lansing himself likely never anticipated.
The D-110F, a 10-inch version of the D-130—the iconic model left behind by James B. Lansing—designed specifically for musical instruments
Since JBL speakers have already received widespread acclaim from all over the world, I feel a bit hesitant to weigh in at this point—but if I had to sum it up in a single phrase, I’d say they’re “just right for listening to music.” It doesn’t feel like I’m listening to “good speaker sound”; rather, I forget about that entirely and simply feel like I’m listening to “good music.” Before I know it, I’m completely captivated by the music playing—perhaps that’s the charm of JBL (especially the older models).
The K Series, which also uses Alnico magnets, took over from the D Series.
The photo shows the 12-inch K120.
The E Series, which switched from Alnico to ferrite magnets.
This is the 15-inch E140, designed for Bass.
Meanwhile, Altec Lansing has continued to lead as a top brand in audio speakers, developing the 417-8HII in the 1970s—a model that could be called a game-changer for instrument speakers. In addition to being the main speaker used in the Mesa/Boogie MK-I and MK-II, it is also known as the speaker favored by Randy Rhoads. Since then, Altec has continued to maintain its position as a frontrunner in the audio speaker industry.In the late 1990s, it became part of the Electro-Voice group and continues to hold a leading position in the audio industry to this day.
A 1970s Mesa/Boogie MK-I equipped with Altec’s epoch-making 417-8H II
Electro Voice, which brought Altec under its wing, was—coincidentally—founded in 1927, just like Jensen and Lansing Manufacturing Co., and began as a microphone manufacturer. It has been selling speakers since 1949, the year James B. Lansing passed away. In addition to being a familiar name in guitar amplifiers—such as the Mesa/Boogie MK-III—it also enjoys immense popularity as a manufacturer of Bass speakers.Even today, as a worthy rival to JBL, it’s a brand frequently encountered in the sound systems of various venues.
A 1970s MK-I hardwood enclosure indicating that Electro-Voice is being used
Resonance: The History of American Speakers
We’ve taken a brief look at the history of American speaker brands, and looking at it this way, I can’t help but feel a sense of destiny—so much so that the phrase “as if by chance” comes to mind time and again. Countless brands have faded into history. And then there are the brands that have carried on their legacy and continue to produce speakers even now. I got the impression that their shared passion for sound resonates with one another, shaping this history.
“Celestion”: Britain’s Legendary Speaker
Meanwhile, across the sea in the United Kingdom, another great legend has emerged: the Celestion speaker, familiar to fans of Marshall. Celestion was founded in 1924—three years earlier than American companies like Jensen, Lansing Manufacturing Co., and Electro-Voice—and is the world’s oldest speaker manufacturer still in production today.Celestion’s story began when its founder, Cyril French, built a small speaker factory in Hampton-with-Church, Kingston upon Surrey—a suburb of London that also served as a filming location for the “Harry Potter” movies. He then enlisted the help of an engineer named Eric Mackintosh, who already possessed advanced technical skills in speaker manufacturing at the time, to begin producing new speakers. Eventually, Cyril French’s three brothers joined the factory.It is said that the name “Celestion” was derived from the word “celestial” (heavenly, celestial, divine) in the hope that the sound would soar “high into the heavens.”The name was chosen by Cyril French’s younger brother, Ralph.
At the time, Celestion manufactured phonographs in addition to speakers. Coinciding with the launch of the British Broadcasting Corporation (BBC) in 1922, the company was propelled by the resulting radio boom, and the sound quality of Celestion speakers spread across the entire United Kingdom via the airwaves.
In the late 1920s, Rola, a speaker manufacturer based in Cleveland, Ohio, established a British factory in Thomas Ditton—just a few kilometers southwest of Celestion—and began producing speakers. Then, in 1942, as demand for military supplies surged due to World War II, Rola transferred its entire speaker manufacturing division to this British factory, while its U.S. facilities shifted their focus to the defense industry, such as aircraft lighting.Empowered by the consolidation of its speaker operations, British Rola acquired Celestion in 1947, following the war. The following year, in 1948, Celestion relocated to British Rola’s facility in Thomas Ditton and made a fresh start as Rola Celestion. In 1949, Rola Celestion acquired Truvox, a company that had been manufacturing audio equipment and speakers in Wembley.Among the engineers who joined the company as a result of this merger was a man named Les Ward. He would go on to develop the legendary G12 speaker, which would make the Celestion name famous worldwide. This encounter between Les Ward and Celestion would later change the course of history. Coincidentally, it was also the year that the American genius James B. Lansing took his own life.
In the late 1950s, a major turning point arrived for Rola Celestion. Les Ward, who had already become a central figure at the company, received a large order for guitar amplifier speakers from Dick Denny of Jenning Musical Industries, an old acquaintance.Les Ward made modifications to the G12—which he had been developing for some time—based on their requests and shipped the speakers. In 1957, the guitar amplifier equipped with these speakers made its global debut as the VOX AC15. Then, in the 1960s, as the Beatles toured the world, they etched the names VOX and Celestion into the global consciousness.
VOX and Celestion
Thanks to the success of these VOX amplifiers, Rola Celestion’s speakers began to attract significant attention from guitar amplifier manufacturers. One of the first to approach the company was Jim Marshall. In 1962—five years after the debut of the VOX AC15—the first Marshall amplifier equipped with Celestion speakers took flight onto the world stage.
A Rola G12 bearing the inscription “THAMES DITTON SURREY ENGLAND”
Having achieved great success with VOX and Marshall, Celestion speakers have remained a symbol of the British sound to this day, used by manufacturers worldwide and loved by players across the globe. In the United States as well, they have been favored by many top brands in recent years—including Mesa/Boogie, Matchless, and Bogner—and are also frequently used in Japanese-made models.
Following the global success of the G12, Rola Celestion expanded its production facilities and established a massive factory dedicated exclusively to the G12 in Ipswich, Suffolk, northeast of London, in 1970. By 1975, all operations—including the headquarters—had been consolidated there, and Celestion speakers continue to be produced at the Ipswich factory to this day.
The G12 Greenback produced prior to the 1970 relocation, commonly known as the “Pre-Rola.”
It bears the inscription “THAMES DITTON SURREY.”
This is a more recent Greenback. It is labeled “IPSWICH, ENGLAND.”
How to Identify Speakers
Most speakers have a label affixed to the back with the manufacturer’s name and other details. However, Fender amplifiers, for example, have a label that simply says “Fender” and does not specify the speaker manufacturer. Additionally, if the label has faded with age and is difficult to read, checking the “factory code” can reveal when and where an American-made speaker was manufactured.
The Fender logo is prominent, but Fender itself does not manufacture speakers.
The factory code is printed on the rim of this speaker.
The factory code is typically a 6-digit number.
The first three digits from the left indicate the manufacturer (220 stands for Jensen); the next digit is the units digit of the year of manufacture (7 for 1957); and the last two digits represent the week of the year (49 indicates the 49th week—roughly from December 2 to December 9).Since the fourth digit, which corresponds to the year of manufacture, shows only the units digit, it is impossible to determine from the code alone whether a “7,” for example, refers to 1957, 1967, or 1977. Therefore, a comprehensive assessment is required based on the speaker’s specifications and the period during which it was manufactured.
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The factory code for this speaker is listed here.
In recent years, Eminence speakers have been labeled as "67-" (followed by an 8-digit number), where the first two digits after "67-" indicate the year.
This one is from 1999.
Which Tweed amp is this speaker mounted on?
Here’s the factory code: 1960 Oxford
How to Determine the Age of a Celestion Speaker
In the case of Celestion, since it is a British speaker, the notation is different and is displayed as two digits and two letters. The two digits indicate the date; the first letter represents the month of manufacture, and the second letter represents the year of manufacture.
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Example: In this case, B = February, L = 1978, and 9 = the date, indicating that it was manufactured on February 9, 1978.
Additionally, the "T1871" shown below is a model version number known as a "T-number," which specifies details such as the voice coil and cone material. It is said that the "T" at the beginning was added by designer Les Ward in honor of Truvox, which was acquired by Celestion.
Try Replacing the Speaker / Power Handling and Impedance
You don’t need any special skills or tools to replace a speaker. Depending on the wiring configuration, many speakers can be replaced without soldering; basically, all you need is a screwdriver and a wrench (pliers will also work).
(With some models, such as combo amps, you may need to disassemble the amplifier section to remove the speaker. For such models, we recommend having a specialist shop handle the replacement.)
You can remove the speaker by unscrewing this nut.
With this type of connector, you can easily attach or detach it without soldering.
Be careful not to mix up the positive and negative terminals!
Rated Input and Impedance
When replacing a speaker, the first priority is deciding “what to replace it with.” We hope this has helped you understand the historical trends of each brand. We’ve also provided information on the sound characteristics of individual models on the product pages of our store’s website, so please feel free to use them as a reference.
When selecting replacement speakers, you’ll need to consider the power handling and impedance. Power handling refers to the maximum output (in watts) that a speaker can handle; exceeding this limit can damage the speaker and may even damage the amplifier itself. As a general rule, choose speakers with a power handling rating equal to or greater than the amplifier’s output wattage. If you’re using multiple speakers, the total power handling is the sum of the power handling ratings of each speaker.
Example: A single speaker with a power handling capacity of 30 W cannot be used with a 50 W amplifier, but if you use two of them, the total power handling capacity becomes 60 W, so they can be used with a 50 W amplifier.
Next, let’s discuss impedance. Speakers operate by receiving current from the amplifier’s output transformer, and impedance is the resistance value that allows them to function efficiently in relation to the amount of current received. Similar to the power handling capacity, speakers cannot be used with an impedance lower than the amplifier’s output impedance (current rating). Doing so can also cause damage or failure.Furthermore, especially with tube amplifiers, even if the speaker’s impedance is higher than the amplifier’s output impedance, the speaker cannot operate efficiently, which may result in reduced response or a sound that seems distant. It is best to choose a speaker with an impedance that matches the amplifier’s output impedance.For example, if the amplifier’s output impedance is 8 Ω, use an 8 Ω speaker. Furthermore, for amplifiers with switchable output impedance settings (such as 8 Ω or 16 Ω), using the speaker at the maximum impedance setting (16 Ω in this case) will result in a higher current output, allowing the amplifier to deliver its power most efficiently.(There’s also a “trick” used with amplifiers like Marshalls: if you can’t get a loud enough sound in a small venue, you can intentionally set the impedance to 4Ω/4Ω and use it as a substitute for an attenuator.) In the case of transistor amplifiers, the minimum impedance is often specified in ohms, so you can use any speaker with an impedance equal to or greater than that value.
Additionally, when using multiple speakers, if they are connected in series, the total impedance is the sum of the individual impedances; if connected in parallel, the total impedance is the individual impedance divided by the number of speakers.
*Please refrain from using speakers with different impedances simultaneously, as this can cause problems and result in poor sound balance.
Top figure (series): 8Ω + 8Ω = 16Ω
Bottom figure (parallel): 8Ω ÷ 2 (number of speakers) = 4Ω
(Impedance in a parallel configuration can also be calculated using Ohm’s Law: 1/A + 1/B = 1/n.)
About Speaker Repairs
With speakers, there are very few parts that can be repaired without specialized technical skills; if you blow out a speaker or tear the cone, you’ll generally have to replace the entire speaker.Unless you possess specialized skills, if you hire a professional technician to repair a speaker—such as by replacing the cone—the cost will almost always exceed the price of a new speaker. Therefore, replacing the speaker is usually the simpler and more cost-effective option. However, in cases involving vintage speakers where no equivalent replacement is available, or if you absolutely require the specific sound of that particular speaker, repairs such as cone replacement or voice coil restoration are possible.
Maintenance Anyone Can Do
As you can see, there are very few parts of a speaker that can actually be maintained. However, while these aren’t exactly “maintenance” tasks, here are some simple checks you can perform. A 12-inch guitar amp speaker typically weighs over 3 kilograms, and some can even weigh close to 10 kilograms. Since these speakers vibrate violently at high volumes, it’s only natural that the screws securing them will gradually loosen.As a result, the speaker’s vibrations aren’t transmitted directly to the cabinet, and—depending on how loose they are—the sound becomes loose and unfocused. For example, if you open up a Marshall cabinet that’s been in use for 5 to 6 years, you’ll find that the speakers inside are almost all loose. Simply tightening these screws again will make the sound noticeably tighter, so if you’ve been feeling that “the sound has lost its edge lately,” it’s worth checking.Depending on the situation, the improvement can be surprisingly dramatic, so if you use your amp frequently at high volumes, it’s a good idea to check periodically for loose screws.
(Every now and then, I come across an old amp in a practice studio that makes me think, “Man, I really want to tighten those speaker screws!” (laughs). Of course, I can’t just go opening up the cabinet and working on it in the studio, so I have to hold back…)
Just tightening these screws will make the sound tighter.
What Is a Speaker?
A device that transmits sound through air vibrations by passing an electric current through a coil to cause a diaphragm to vibrate. That is the definition of a speaker. In other words, what we’re actually listening to are the air vibrations delivered by the speaker. Sound is air. I don’t usually think about it that way, but there was an experience that really brought that home to me, so I’d like to share it with you at the end.
A few years ago, when I was in the U.S., I was utterly stunned by the music coming from the ceiling of a bus. It was a famous Eric Clapton song—I’m not exactly a die-hard fan, but I’d heard it countless times at home on CDs, on the radio, and as background music in stores I’d stopped by. To be blunt, it was a song I’d heard to death. Yet I found myself wondering, “Why does this guitar sound so breathtakingly beautiful?”When I looked up, I saw it was coming from a tiny speaker embedded in the ceiling of a cheaply built bus—and it was playing in mono, no less. Acoustically, it certainly wasn’t an ideal environment, but I could hear frequencies I’d never heard before, and if sound had a color, it appeared to me in vivid, distinct hues. It was then, for the first time, that I truly realized, “This sounds different from how it does in Japan.”
Since then, I’ve come to realize—albeit belatedly—that if I pay just a little attention, I can hear the sounds of sunny days on sunny days and the sounds of rain on rainy days. Listening with that sensibility, I’ve come to believe that records from the ’60s capture the sounds of the ’60s atmosphere, and records from the ’70s capture the sounds of that era’s atmosphere as well.(I wonder what it’s like with recent digital recordings.) After talking so much about speakers, it might seem counterproductive to end by mentioning “the air” (what was the point of all that…?), but it made me realize once again that we’re listening to the sound of the air through various speakers, and I’d like to wrap up this post with that thought.
Let’s cherish the air.