JBL manual S4800 SWITCH OPERATIONS, Model S4800, Lf Input, Hf - Uhf, Controls And Connections

CHAPTER 6 – S4800 SWITCH OPERATIONS

The S4800 has an HF trim switch mounted on the network panel on the rear of the enclosure. The HF Trim Switch £adjusts the high-frequency level over the range of approximately 1000Hz to 10kHz. The +1dB position gives the highest HF output and measures the most level. 0dB reduces the HF level by 1dB, and the –1dB position reduces the HF level by an addi- tional 1dB.

Although the range of these control settings is rather small, each of them operate over a reasonably wide frequency range and thus have a noticeable effect on the overall tonal balance of the system. It is recommended that the system first be played with the switch in the middle position. This setting gives the most uniform measure- ments in a controlled environment. Of course, we are interested in pro- ducing the most pleasing sound in your environment with your choice of program material. It is, therefore, recommended that the HF Trim Switch £be tested in its various settings on a variety of program material. Once you become familiar with their individual character, you should have no difficulty determin- ing the setting that produces the most pleasing, natural sound in your room with your equipment.

CONTROLS AND

CONNECTIONS

	Model S4800
		¡
		HF - UHF
		INPUT
	–	HF - TRIM	+1dB	+
™			+0dB
		£	–1dB

¢

LF

INPUT

JBL Incorporated, Northridge, California USA

Figure 8. S4800 controls and connections.

™

¡Mid-/High-Frequency Input Terminals: For bi-wire configura- tions, connect the speaker wires for the mid- and high-frequency ranges to these terminals.

™Shorting Straps: Leave the shorting straps in place only if you are using the passive single- wire connection option described on page 13. Otherwise, remove the straps to prevent possible damage to the speakers or your electronics.

£HF Trim Switch: This switch allows you to adjust the output of the high-frequency transducers to compensate for the acoustics of your room. The +1dB position

increases the output, the 0dB position is a flat-level position, and the –1dB position decreases the output. Each position will affect the tonal balance over

a wide frequency spectrum. Experiment by placing the switch in each position while listening to familiar program material and choose the position that suits your room acoustics and listening preferences. You may find after a few months, once the transduc- ers have settled in, that another adjustment is necessary. This

is normal. The switch may be adjusted using a flat-head screw- driver.

¢Low-Frequency Input Terminals: For bi-wire configura- tions, connect the speaker wires for the low-frequency range to these terminals.

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