In Parts 1 and 2 we discussed Peter Jensen’s journey from his birthplace in Denmark to California, his involvement in the creation of the moving-coil loudspeaker, and his role as co-founder of the Magnavox company.
In 1927, Jensen left California and Magnavox and moved to Chicago. There he founded the Jensen Radio Manufacturing company, which produced loudspeakers for radio manufacturers. Within two years, the new company was providing OEM speakers for 60% of independent radio manufacturers in the US. Somewhat ironically, the company had to license from Magnavox, technology that Jensen had invented.
Given his pioneering spirit, it wasn’t surprising that Jensen continued to investigate ways to improve his invention. He soon realized that it was essentially impossible to cover the full audible range of sound utilizing one speaker driver. Aside from the added complexity of an additional driver, keep in mind that nearly all speakers built before the end of WW II utilized electromagnetic (or “field coil”) magnet assemblies; the “permanent magnets” that existed were neither truly permanent nor sufficiently strong to work well in quality speakers. In addition to the standard signal leads, each speaker driver required connections to a power supply for the electromagnet. Baby boomers and those younger may find the connections found on the back of vintage loudspeakers bewilderingly complex.
But I digress. By 1929, when his company first introduced a speaker system labeled “Imperial”, Jensen produced separate woofers and tweeters (and yes, those terms were often used to describe low- and high-frequency drivers even then). In addition to their inclusion in a stunning black lacquer and maple art deco 2-way system called the “Imperial Reproducer”, Jensen’s drivers were used in console radios that defined the state of the art, built by the grandly-named E.H. Scott and McMurdo Silver. Lest you think that the pursuit of high-fidelity sound is a recent pursuit, Scott’s top model, the Quaranta, sold for $2500 in 1936! —which, translated to 2016 dollars, is over $43,000.
Considering that the complete Quaranta weighed over 600 pounds, the buyer got a lot for his money: in addition to the AM and Shortwave receivers (whose performance defined the state of the art at that time), the system contained a Garrard record changer, and a Presto cutting lathe with a ribbon microphone, for in-home recording sessions. Jensen’s contributions were in the 5-driver 3-way speaker system: a massive 18” woofer, comparable to the model 4181 which Jensen manufactured for Western Electric theater systems, 2-12” Magnavox midranges (yes, 12” mids), and 2-Jensen horn tweeters which look suspiciously similar to the Western Electric model 597 tweeter used in WE’s best theater systems.
Aside from the novelty of a 3-way speaker system in 1936, consider that the speakers were triamplified as well, with the bass amp handling 30-125 Hz, the midrange amp handling 100-6,000 Hz, and the treble amplifier covering 3,000- 16,000 Hz. The frequency range of the speakers exceeded that of the Quaranta’s sources, as neither AM radio nor 78 rpm records often extended above 5,000 Hz during that era.
The drivers that Jensen manufactured for Western Electric were component parts of the most elaborate and sophisticated theater and PA systems then built, which in many ways are superior to today’s theater systems. Much of the fundamental research on human hearing, psychoacoustics, intelligibility of speech and sound quality was done by Bell Labs scientists, whose work shaped the designs of their colleagues at WE.
Jensen’s 18” woofer, manufactured for Western Electric as their model 4181, was a massive device whose cast frame and bulky field coil assembly looked more like the creation of a blacksmith, rather than something designed by an acoustician or electrical engineer. Demand for the 4181 and its Jensen equivalent are still strong; intact, clean units go for over $4,000 on Ebay.
In addition to being part of the biggest, baddest multi-way systems, Jensen developed the first true coaxial speaker system, in 1942. The next year, 1943, Jensen again moved along to start a new company, Jensen Industries.
Post-war, the new company focused upon the burgeoning hi-fi and musical instrument markets, and developed complete speaker systems as well as raw drivers. From the ‘40’s through the ‘60’s, Jensen speakers could be found in guitar amps made by Fender, Gibson, and other leading companies. In the ‘50s, and early ‘60’s, Jensen’s 500-series coaxial speakers and G-610 triaxial were often recommended for hobbyists building their own speakers, or for use in custom consoles due to their combination of high performance and compactness. (Those raised in the ‘60’s and ‘70’s likely recall Jensen coax and triax car speakers, which were among the first and most popular aftermarket car speakers.)
The upper end of the ‘50’s market was covered by the Imperial systems, large horn-loaded enclosures with prodigious bass, still built by hobbyists for that reason. As was common practice during the period, the enclosure could be ordered with a variety of driver configurations, starting with a coax unit and ending with a 3-way system. The full-tilt 3-way Imperial sold for $570 in 1957, equal to almost $5000 today.
Massive enclosures like the Imperial (and its rivals, the JBL Hartsfield, Klipschorn, and Altec Laguna) fell from favor with the transition from mono and stereo and the appearance of high-performance smaller speakers like the AR-3 and 3a (and the higher-powered amps such systems required). The tweeter section alone of the Jensen Imperial was about the size of most complete AR systems of the period.
Peter Jensen died in 1961. A lifelong smoker, he succumbed to lung cancer at the age of 75.
While the company continued to manufacture speaker systems for decades after its founder’s death, it essentially became a me-too brand, building speakers that offered solid value but uninspiring performance: the audio equivalent of, say, Buick.
As was true of far too many legendary hi-fi brands, the company was sold so many times that constructing an accurate history is nearly impossible. Archives appear to have vanished decades ago.What’s left of the Jensen brand, these days? The brightest spot in that story is that Jensen speakers for guitar amps have been faithfully reproduced since the 1990s by an Italian company.
On the hi-fi side, all that remains is a line of cheesy accessories and mobile electronics sold under the Jensen brand name. The brand’s fate is similar to that of the Advent, RCA, and Acoustic Research Brands, which are also owned by Voxx Corporation—once known as Audiovox. Acoustic Research has at least recently introduced a competent digital audio player; Jensen has had no such luck.
Peter Jensen—and his legacy of innovation—deserves better.
Bill Leebens has bought and sold vintage gear since the days when it was new. He regrets that a goodly number of classic American components now reside in Japan, because of him. Mea culpa.