JBL C50SM
The JBL C50SM is JBL's first studio monitor, introduced in 1962. It uses the same driver complement as the home-oriented Olympus system, scaled down into a more compact sealed enclosure. Bart Locanthi and Edward Long designed it. It led directly to the far more famous JBL 4320 and the whole 43xx monitor series that followed. The C50SM/S7 variant shares its driver configuration with the later 4320.
The C50SM came in six variants - C50SM/S6, S7, S8, S12, S14, and LE14C - each pairing different drivers and crossovers for different uses. The S7 is generally considered the best of them. It used an LE15A woofer with an LE85 driver on an HL91 horn, crossed over by an LX5 network. The S8 changed over its production life. The 1962 version was a 2-way with a 375 driver on an HL93 horn. The 1964 version added a 075 ring-radiator tweeter and an N7000 crossover, which made it a 3-way. The S12 and S14 (both from 1964) used the smaller LE14A woofer. The S14 had an LE75+HL91 top end and the S12 an LE20 tweeter. The LE14C variant from 1962 used an LE14C woofer with an LX2-1 network. All variants shared the same cabinet: 590mm wide, 760mm high, and 500mm deep. It was fully sealed (closed-box), which was unusual for JBL at the time, and one of the first fully sealed studio monitors on the market. Japanese sources note that early versions used Douglas fir plywood. The cabinets were finished in gray with large, striking logos.
Professionals did use it. Capitol Records, CBS Columbia, RCA-Victor, MGM, Decca, and ABC Broadcasting, among others, adopted it for checking recording quality. That helped JBL break into a professional studio market that had been dominated by Altec and Tannoy. Even so, the C50SM was never a big seller, and its studio acceptance was not particularly widespread. Sales volume was extremely small compared to later JBL monitors, so complete original examples are now rare on the used market. Japanese collector sources note that almost no complete originals remain available. Used market prices for the S7 and S8 have been recorded at ¥351,000 and ¥486,000 respectively.
Sources conflict on whether the C50SM is a 2-way or 3-way system. It depends on the variant and year. The 1962 S8 is a 2-way, the 1964 S8 is a 3-way, and the other variants are all 2-way. No frequency response, sensitivity, impedance, or crossover frequency specifications have surfaced in the available documentation.
- Type: Sealed (closed-box) studio monitor, floor-standing
- Variants: C50SM/S6, S7, S8 (1962 & 1964 versions), S12, S14, LE14C
- Dimensions: 590 × 760 × 500 mm (W×H×D)
- Weight (packed): 40.8 kg
- Designers: Bart Locanthi and Edward Long
- First JBL studio monitor; direct predecessor to the 4320 and 43xx series
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