ONE USED LOUDSPEAKER - EARLY ELECTRO-VOICE SP 12B 12” WIDE RANGE DRIVER

Description

Untitled Document
ONE USED LOUDSPEAKER
ELECTRO-VOICE SP 12B
12” WIDE RANGE DRIVER
This Electro-Voice SP12B 12” wide-range speaker is an original
model
with a maroon painted frame; we have also listed a second, later vintage, SP12B with the same chassis and a reinforced red-paper edge. And a third SP12B which looks quite different, with a beefier more angular
light gray
chassis and the same cone as SP12B #2, with a reinforced red-paper edge.
The edge surrounds of this driver were coated with flexible silicon on front and back sides to seal a few minor stress cracks and prevent development of new cracks. Other than the newly coated pleated paper surround the speaker is undamaged. The maroon hammer-tone paint by the way
is beautiful, like new.
The serial number stamped on the aluminum badge is 30192.
There is no part number stamped on the cone but I am 100% sure it is the original part.
As you can see in the photos, the original 12B does not have the wide heavy duty pleated orange paper edge of the later 12B. Also, this driver has a gray plastic dust cap, not a paper one like the later vintage 12B (shown in the last photo).
This wide range driver has a DCR of 11.6 Ohms which is correct for this nominal 16 Ohm driver.
This 12" EV speaker is often found in the original Klipsch Heresy.
This driver is wide range; 30 Hz to 13 kHz
RETMA Sensitivity
(1mW/30 feet)
is 46.5 (= 95.5 dB 1watt/1 meter)
Power Handling: Program material 20 watts; 40 watts peak
Impedance is 16 Ohms
Mechanical crossover to whizzer cone is 3.5 kHz
Voice coil diameter is 2 inches
Alnico magnet weight is 1 pound
Diameter is 12.25 inches
Overall depth is 7 inches
Weight is 12.25 pounds.
This driver was tested loose, ‘out of the box’, this morning and it sounded fine. There wasn't much bass without the driver installed  in a cabinet of course.
No rubbing or scraping, I heard nothing weird. It works as it should, like new.
The Alnico magnet is apparently at full strength, the speaker plays nice and loud.
This speaker will be safely packed in a 12” x 16” (approx.) box, which will weigh about 20 pounds.
Electro-Voice
(
EV
) is an American manufacturer of audio
equipment, including microphones
, amplifiers and loudspeakers
, focused on pro audio
applications such as sound
reinforcement
. As a subdivision of Telex Communications
Inc. since February 1998, Electro-Voice markets products for use by consumers as well as small or large concert venues, broadcasting, houses of worship, and in retail situations.
On September 1, 1927, Lou Burroughs and Albert R. Kahn began a small business called Radio Engineers, servicing radio receivers in the basement of the Century Tire and Rubber Company in South Bend, Indiana. Because of the Great Depression, according to Kahn, “We found ourselves insolvent to the extent of ,000” (,106 today). They decided to focus their business on audio products. The company designed a PA system for Notre Dame football coach Knute Rockne. Rockne, who had difficulty being heard at football practices due to health problems that affected his voice, called the new PA system his "electric voice". Rockne's remark inspired the company's name. On June 1, 1930, Burroughs and Kahn incorporated under the name "Electro-Voice".
The partners recognized an opportunity to capitalize on what they perceived as the generally poor quality and high prices of existing microphones. They purchased a lathe and a drill and started producing about one microphone a week. Soon after, Burroughs withdrew from the business, leaving complete ownership to Kahn. By 1933, the previous business debts were completely paid off, and Electro-Voice began hiring manufacturing employees. In 1936, twenty people were hired, and Lou Burroughs returned as chief engineer.
During World War II, EV developed the noise-cancelling microphone. Noise cancelling microphones such as the Electro-Voice T45 lip microphone were instrumental to fighter and bomber airplane, tank, battleship and ground troop radio communications. EV licensed the patent to the government for free to be applied by other manufacturers to produce what was needed for the war supply.
In 1946, the business moved to a bigger facility in Buchanan, Michigan, and expanded its engineering efforts. In 1948, they began successfully producing phonograph pickup cartridges. In 1950, they started production of the first automatic TV signal booster. They also started to design and produce a consumer loudspeaker line in response to increased public interest in Hi-Fi music listening. In 1952, EV patented the Compound Diffraction Horn, which changed the look and performance the traditional cone-shaped paging horn. Known for its high output, the CDP was deployed by the Navy on aircraft carriers and other high noise environments.
In 1963, EV received an Academy Award for their 642 Cardiline shotgun microphone, the first ever given for an audio product.
Electro-Voice launched its RE Series of microphones in the 1960s, notably the RE15, which was used extensively by musicians on television shows. The RE series used "Variable D" technology first developed by EV in 1953, which eliminated changes in tone and frequency response corresponding to changes in the physical distance of the sound source from the microphone. The RE20 broadcast microphone was introduced in 1968, followed by the RE27N/D in the late 1980s, using neodymium magnets. Both continue to be used in recording studios and on the concert stage.
In the early 1970s, EV developed the first commercial system for matrix four channel stereo called Stereo-4. When Columbia/CBS and Sony developed their Stereo Quadraphonic system (SQ) that system became the leading matrix system. Electro-Voice then adapted their decoders so they also could play SQ records as well as Sansui's QS records. The EV system could also simulate four channel sound from two channel sources.
Also in the 1970s, EV acquired TAPCO. The company, founded by Greg Mackie, specialized in audio mixers. TAPCO products soon became prominent in the EV product line.
In 1978, Electro-Voice patented its Constant Directivity Horn, which produced an even balance of frequencies across the listening field. It overcame the uneven dispersion of high frequencies that affected the typical high frequency horns used in many professional sound speakers until the late seventies.
In the late 1980s, EV became the first microphone manufacturer to use neodymium magnets in its microphones. The N/DYM microphones were introduced in the mid 1980s to combine the high output and high frequency response characteristics of condenser microphones with the rugged shock resistance of dynamic microphones. Around the same time EV's first wireless microphones were being produced.
Electro-Voice
(
EV
) is an American manufacturer of audio
equipment, including microphones
, amplifiers and loudspeakers
, focused on pro audio
applications such as sound
reinforcement
. As a subdivision of Telex Communications
Inc. since February 1998, Electro-Voice markets products for use by consumers as well as small or large concert venues, broadcasting, houses of worship, and in retail situations.
On September 1, 1927, Lou Burroughs and Albert R. Kahn began a small business called Radio Engineers, servicing radio receivers in the basement of the Century Tire and Rubber Company in South Bend, Indiana. Because of the Great Depression, according to Kahn, “We found ourselves insolvent to the extent of ,000” (,106 today). They decided to focus their business on audio products. The company designed a PA system for Notre Dame football coach Knute Rockne. Rockne, who had difficulty being heard at football practices due to health problems that affected his voice, called the new PA system his "electric voice". Rockne's remark inspired the company's name. On June 1, 1930, Burroughs and Kahn incorporated under the name "Electro-Voice".
The partners recognized an opportunity to capitalize on what they perceived as the generally poor quality and high prices of existing microphones. They purchased a lathe and a drill and started producing about one microphone a week. Soon after, Burroughs withdrew from the business, leaving complete ownership to Kahn. By 1933, the previous business debts were completely paid off, and Electro-Voice began hiring manufacturing employees. In 1936, twenty people were hired, and Lou Burroughs returned as chief engineer.
During World War II, EV developed the noise-cancelling microphone. Noise cancelling microphones such as the Electro-Voice T45 lip microphone were instrumental to fighter and bomber airplane, tank, battleship and ground troop radio communications. EV licensed the patent to the government for free to be applied by other manufacturers to produce what was needed for the war supply.
In 1946, the business moved to a bigger facility in Buchanan, Michigan, and expanded its engineering efforts. In 1948, they began successfully producing phonograph pickup cartridges. In 1950, they started production of the first automatic TV signal booster. They also started to design and produce a consumer loudspeaker line in response to increased public interest in Hi-Fi music listening. In 1952, EV patented the Compound Diffraction Horn, which changed the look and performance the traditional cone-shaped paging horn. Known for its high output, the CDP was deployed by the Navy on aircraft carriers and other high noise environments.
In 1963, EV received an Academy Award for their 642 Cardiline shotgun microphone, the first ever given for an audio product.
Electro-Voice launched its RE Series of microphones in the 1960s, notably the RE15, which was used extensively by musicians on television shows. The RE series used "Variable D" technology first developed by EV in 1953, which eliminated changes in tone and frequency response corresponding to changes in the physical distance of the sound source from the microphone. The RE20 broadcast microphone was introduced in 1968, followed by the RE27N/D in the late 1980s, using neodymium magnets. Both continue to be used in recording studios and on the concert stage.
In the early 1970s, EV developed the first commercial system for matrix four channel stereo called Stereo-4. When Columbia/CBS and Sony developed their Stereo Quadraphonic system (SQ) that system became the leading matrix system. Electro-Voice then adapted their decoders so they also could play SQ records as well as Sansui's QS records. The EV system could also simulate four channel sound from two channel sources.
Also in the 1970s, EV acquired TAPCO. The company, founded by Greg Mackie, specialized in audio mixers. TAPCO products soon became prominent in the EV product line.
In 1978, Electro-Voice patented its Constant Directivity Horn, which produced an even balance of frequencies across the listening field. It overcame the uneven dispersion of high frequencies that affected the typical high frequency horns used in many professional sound speakers until the late seventies.
In the late 1980s, EV became the first microphone manufacturer to use neodymium magnets in its microphones. The N/DYM microphones were introduced in the mid 1980s to combine the high output and high frequency response characteristics of condenser microphones with the rugged shock resistance of dynamic microphones. Around the same time EV's first wireless microphones were being produced.