What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

JBL L100 Century

 The L100 Century is the most successful bookshelf loudspeaker ever produced by JBL. It may be the most successful loudspeaker in its class ever produced by anyone.
But we don't expect you to take our word alone. The plain fact is that the L100 was offered for home use only after it proved to be a runaway bestseller with studio recording engineers - the most demanding listeners you'll ever find.
This professional acceptance was no accident. The speaker was originally developed and offered for sale as a control monitor for recording studios.
 Technical Information
Low Frequency
Music below 1500 Hz is reproduced by a powerful 12 inch, long excursion loudspeaker with 3-inch edgewound copper ribbon voice coil, massive magnetic assembly, and large Alnico V magnet.
The cone is molded in a shape which makes possible uniform wide angle didstribution of the full low frequency range, and is coated with an exclusive damping factor damping compound, which prevents unwanted reverberations traveling within the cone material. An enclosure with a tuned port is employed to optimize bass efficiency and dynamic range.
Vocals and midrange sounds are reproduced by a 5-inch transducer having high sensitivity and power handling capacity. A 7/8" copper voice coil, suspended in an intense magnetic fieldprovided by a 2,75-pound magnetic assembly energized by an Alnico V magnet, drives the midrange transducer.

 High frequency
Delicate treble fundamentals, overtones and harmonics above 6000 Hz are reproduced by a 1,4-inch direct radiator. Its 5/8" copper voice coil is unusually large in relation to cone diameter, for greatest efficiency and transient response. Suspending the outer edge of the cone assembly with an impregnated cloth and surrounding the entire dynamic structure with a ring of dense foam eliminates unwanted rediations and reflections. The smal surface of the cone and center dome is responsible for uniform high frequency dispersion.

Dividing Network
The function of the network is far more complex than merely diverting low and high notes to a woofer and tweeter respectively; it wastes none of the power that should be used to drive the loudspeakers; it precisely controls each speaker's operation in the transition frequency range. Controls on the front of the cabinet, behind the removable foam grille, permit  adjusting midrange and high frequency levels for greater or less audible output in relation to the bass.
 Power handling capacity
The specified power handling capacity indicates the continuous program level that can be accepted by a JBL loudspeaker system without damage. Its peak power handling capacity is considerably greater than the continuous rated value, as reflected in the remarkable transient response of JBL loudspeaker system components.
The L100 will produce clean sound at comfortable listening levels when driven by an amplifier having an output of as little as 10 Watts RMS per channel.
However, for reproduction of the full dynamic range of contemporary recordings at high volume, a quality amplifier delivering up to 150 Watts RMS per channel will provide optimum performance. Such an amplifier has the reserve power necessary for accurate reproduction of transients, which can reach momentary peaks equivalent to ten times tha average power level. In almost all cases, the volume level generated by a JBL loudspeaker will become noticeably discomforting to the ear before the loudspeaker can be damaged by excessive power from the amplifier.

Only furniture hardwoods, hardwood veneers, and compressed woods are used. Tight, wood-welded, hand-fitted joints eliminate undesirable resonance  and warpage. Hand-rubbed oiled walnut finish on all four sides permits the l100 Century to be placed in either an upright or horizontal position.
Power Capacity:  50 watts continuous program
Nominal Impedance:  8 Ω
Crossover Frequencies:  1500 and 6000 Hz
Efficiency:  78 dB Sound pressure Level at distance of 15', 1 watt input
Low Frequency Loudspeaker
Nominal Diameter:  300 mm (12")
Voice Coil:  76 mm (3") edgewound copper ribbon
Magnetic Assembly Weight:  3,1 kg (6,75 pounds)
Flux Density:  10,400 gauss
Sensitivity:  42 dB
Midrange Transducer
Nominal Diameter:  130 mm (5")
Voice Coil:  22 mm (7/8") copper
Magnetic Assembly Weight:  1,2 kg (2,75 pounds)
Flux Density:  16,500 gauss
EIA Sensitivity:  46 dB
High Frequency Direct Radiator
Nominal Diameter:  36 mm (1,4 ")
Voice Coil:  16 mm (5/8") copper
Magnetic Assembly Weight:  0,7 kg (1,6 pounds)
Flux Density:  15,000 gauss
Sensitivity:  47 dB
Finish :  Oiled walnut
Grille Color Options:  Ultra Blue; Chocolate Brown or Burnt Orange
Dimensions (W x H x D):  360 c 600 x 350 mm (14-1/4" x 23-1/2" x 13-5/8")
Weight (shipping):  25 kg (55 lbs)

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