EXCELLENT LOUDSPEAKER - (JENSEN P15LL) KLIPSCH K-33-J 15” LOW FREQUENCY DRIVER

Description

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EXCELLENT LOUDSPEAKER
(JENSEN P15LL) KLIPSCH K-33-J
15” LOW FREQUENCY DRIVER
This Klipsch-branded Jensen P15LL 15” low frequency loudspeaker has a DCR of 2.7 Ohms which is correct for this nominal 4 Ohm woofer.
The Klipsch serial number on the undamaged ‘chrome’ foil label is 2291.
A six digit ID number,
‘220 6 38’, is stamped on the frame.
This indicates a Jensen (220) speaker manufactured during the 38th week (38) —
between Oct. 7 and Oct. 14 — of the year
1956 (6)
.
As you can see in the photos the paint has a few minor rough spots but the frame and the cap are undamaged. No dents or dings.
Underneath the cap, as you can also see in Photos, is a huge Alnico V magnet.
The original Jensen cone —
part no. 3015002-H6 — looks perfect, like new.
The woofer was tested loose, ‘out of the box’, this morning and it sounded fine.
Years back I had this woofer in one of a pair of Klipschorns set up in my listening room. Both K-horns always sounded great, worked perfectly… and were never abused by the way.
This Jensen bass speaker was built specifically for the Klipschorn but would work fine in Altec VOTTs or similar boxes.
The Jensen woofer is quite similar to the Stephens Model 103 and the Electrovoice 15Wk. Both of those 4-Ohm woofers were also built specifically for the Klipschorn.
Why are all these K-horn woofers 4 Ohms... when the midrange driver and tweeter are usually 16 Ohms?
Here’s why: In a 1950s article written for
Audio
magazine, Klipsch stated he ordered 4-Ohm woofers for his big horns because the small ‘compression chamber’ in the Klipschorn increases
impedance.
Please see the photos to check cosmetic condition and DCR.
The speaker is 8” high and 15” in diameter.
Each speaker weighs 14 pounds, 4 ounces.
The Jensen/Klipsch speaker will be safely packed in one 20” x 20” X 12 (approx.) box, which will weigh about 25 pounds.
This driver was tested loose, ‘out of the box’, this morning and it sounded fine.
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 30 pounds.
Peter Laurits Jensen
(16 May 1886 – 26 October 1961) was a Danish American
engineer, inventor and entrepreneur. He founded Magnavox
Company and Jensen Radio Manufacturing Comany
.
Jensen was born on May 16, 1886 near
Stubbekøbing
on the island of Falster, Denmark
. His parents were Lods Ole Jensen a navigator and Hansine petersen Jensen. His education began in the village school of Moseby where he showed some promise, he later studied at the boarding school in Norre Alslev
and three years later he passed the entrance exam for Copenhagen University
.
He died in 1961 in Western Springs, Illinois
, at the age of 75.
Jensen began employment as an apprentice in the laboratory of Valdemar Poulsen, the inventor of magnetic recording and the Poulsen System of Radio in 1903. He became an assistant to Poulsen in 1905 and was sent to the United States to assist in introducing the Poulsen Radio Arc System in 1909. He was employed as engineer by the Federal Telegraph Company in California, which purchased the Poulsen patent, in November 1910.
In 1911, he co-founded with Edwin S. Pridham (1881–1963) the Commercial Wireless and Development Co. in Napa, California, utilizing the financial backing of Richard O'Conner and the engineering assistance of master mechanic Carl Albertus. Jensen and Pridham moved from Napa in 1916, and changed the company name in 1917 to the Magnavox Company. Jensen was employed as chief engineer until 1925.
He built with Edwin S. Pridham the first moving coil loudspeaker in 1915. Called the moving coil principle, the electro-dynamic principle from which the term dynamic speaker later evolved. In 1916 he built and patented the first contained and complete electric reproducing phonograph. He made the first public address system and used it on Christmas Eve of 1915 in San Francisco at a gathering of 75,000 people, who heard distinctly all the speeches and announcements.
Soon
after public address systems under the name of Magnavox were used all over the United States, including by U.S. President Woodrow Wilson
in 1919. World-wide there were no other companies manufacturing public address systems until 1920. Jensen designed the Magnavox dynamic loudspeaker for reception of radio broadcasting in 1919.
He also invented and patented, with Edwin S. Pridham, the first anti-noise self-neutralizing microphone in 1917 which allowed wireless communication between aircraft and the ground. This type later became known as the lip microphone, widely used in the First and Second World Wars.
Jensen resigned from Magnavox in 1925, and founded the Jensen
Radio
Manufacturing Company
in 1927. He marketed speakers under the trade name "Jensen". He remained president of the firm until 1940. He was a consultant to the Radio and Radar Division of the U.S. War Production Board in Washington D.C.
from 1942 to 1946. In 1945, he founded Jensen Industries Inc. for the manufacturing of phonograph needles—and, later, of the stainless steel sink.
Jensen was made an honorary Member of the Audio Engineering Society
in 1955. He was also honored by the American Institute of Radio Engineers. He was elected an Extraordinary Member of the Danish Engineering Society, and knighted by the King of Denmark
in the Order of the Dannebrog
.
Jensen Loudspeakers
is a company that manufactures speakers in many different models and sizes.
Originally located in Chicago Illinois, the company built a reputation providing professional PA and movie theater speakers and home hi-fi speakers. Jensen also built 18
”
field coil woofers for Western Electric theater systems.
In the mid forties
Jensen produced the speaker for
the first Fender guitar amplifier,
as well as DIY components and
home hi-fi
speaker systems. By that time Jensen were no longer producing ultra-high quality field-coil speakers like the ones built for Western Electric.
The current Fender Twin Reverb amp uses two 12" Jensen C-12K speakers.
The former Jensen Radio Manufacturing Company was founded in 1927 by Peter
Laurie’s
Jensen
, co-inventor of the first moving coil loudspeaker
.