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 - Ranger Metregon C45

 The  JBL Metregon (1960) is the first speaker system to offer full-field stereo reproduction in an enclosure of moderate size. Two completely separate full-range speaker systems are housed in the Metregon. Sound from these two sets of speakers is integrated by the curved refractor panel, making use of the same acoustic principles as the JBL Ranger Paragon. The result is a full-dimensional sound stage six feet wide. There is no "hole in the middle", no "split soloist", to mar the illusion of a real performance.
Like the Paragon, the JBL Metregon projects perfectly balanced stereophonic sound to every listener in the room, regardless of seating position. Like the Paragon, it also performs superbly as a monaural reproducing system.
The JBL Metregon C45 is selected by the pasadena Art  Museum for showing in tri-annual industrial design exhibition.

 The curved refractor panel used exclusively in JBL integrated stereo systems integrates the two separate stereo channels into a single three-dimensional sound source. It not only produces a smooth transition from one source of sound to the other, but disperses the sound pattern over a wide area.
The two separate full-range speaker systems housed in the Metregon face into the edges of the refractor panel. Sound generated by these speakers tends to flow along the curved surface of the panel. It is projected outward from the refractor by a complicated interplay of reflection and constructive interference. The listener hears sound directly from the loudspeakers as it is projected across the full width of the curved acoustic refractor. Individual instruments are pinpointed at the position they were recorded. The effect is comparable to dimensions achieved when a moving picture is projected on a wide curved screen.
Since the JBL Metregon generates a stereophonic sound field within the loudspeaker system itself, there is no need to sit in a particular location to hear three-dimensional sound. Every listener in the room hears a single blended performance, just as if the artist were actually in the room.
 Additional loudspeakers which can be accommodated in the C45 enclosure.
Since both the low and high frequency drivers face into the curved refractor panel, other JBL loudspeaker systems, in addition to the 205 system , can be installed in the Metregon. Pairs of JBL Extended Range Speakers D123, D130 or D131 can be used alone. These can be built up to two-way systems by addition of the JBL 075 High Frequency Driver and the N2400 Dividing Network. In addition, the JBl Stereo Systems 201 and 282 can be installed.
The list of the components used in the eight basic JBL systems compatible with the C45 Metregon enclosure.

Loudspeaker Components used in the JBL Metregon
The Metregon reproducer is designed especially to match the JBl 205 loudspeaker system. This consist of two matched sets of components. Each set includes a JBL 130A low frequency driver,  model 275 high frequency driver, H5040 cast exponential horn, and N600 crossover network. The bass driver are loaded by individual matched-reflex chambers. A low crossover frequency of 600 Hz enables the radiant dispersion principle to be utilized to best possible advantage.

 Components Specifications
JBL 130A - Maximum efficiency low frequency loudspeakers designed primarily for use with the 175 DLH high frequency assembly. The 130A have 4" edgewound copper ribbon voice coil and long magnetic gaps for crisp reproduction of bass tones. Normally,a single 130A is used together with the 175DLH and N1200 dividing network, in larger enclosures where two bass drivers can be installed. For reflex or horn-loaded enclosures.
Impedance:  16 ohms
Power Capacity:  25 watts
Free Air Cone Resonance:  29 cps
Frame: Rigid cast aluminum
Field:  Permanent Alnico V Magnet
Magnetic assembly:  11,5 lbs
Weight:  23 lbs (shipping)

JBL 275 - This new driver is a more massive version of the well-known JBL 175. Newly designned magnetic circuit with increased gap energy results in improved linearity at highest audio frequencies. For 2-way systems crossing over at 600 Hz
Impedance:  16 ohms
Flux density:  18,500 gauss
Voice coil diameter:  1-3/4"
Power Capacity:  25 watts above 500 Hz
Weight:  15 lbs (shipping)

JBL H5040 - Cast aluminum exponential  horn. Used with 175 and 275 drivers in JBL systems crossing over at 600 Hz and above. Designed primarily for JBL-Ranger Mertregon
Weight:  5 lbs (shipping)
 JBl N 600 - The dividing networks on this page are constructed of highest quality precision components, hand wired and individually checked to meet precision component tolerances. A 3 position switch allows the intensity of the high frequency trasducer to be adjusted for optimum results in any acoustic surroundings. Used with JBL 130A or 130B bass drivers and 275 high frequency driver
Attenuation:  12 dB per octave on each side of crossover frequency
Crossover Frequency:  600 Hz
Impedance:  16 ohms
Dimensions:  4-3/4" x 6" x 6-1/4"
Weight:  10 lbs (shipping)

The JBL C45 enclosure is available in the following fine wods and finishes: light or dark Walnut, light or dark Mahogany, light Oak, Salem Maple, Natural Birch, Korina and Ebony.
Height:  30"
Width (top):  73-11/16"
Depth:  22-1/2"

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