JBL System Design Using the GTS300 or GTS600, Wiring, Speaker Requirements, Signal Sources

3.System Design Using the GTS300 or GTS600:

3.1 Speaker Requirements

When used in the non-bridged mode the GTS300 or GTS600 can easily drive 2 ohm speaker loads. When only one speaker is connected to each channel, virtually any conventional speaker may be used.

When the GTS300 or GTS600 is in bridged mode, the combined impedance of the speaker (or speakers) connected to the bridged channel should be at least 4 ohms. Sustained operation of the GTS300 or GTS600 in bridged mode with less than 4 ohms will likely cause overheating.

The GTS300 or GTS600 must not be used with speakers that have either one of their input terminals wired to the frame of the speaker or to the chassis of the vehicle.

Parallel Wiring

(+)
2 Ohms	4 Ohms	4 Ohms
Nominal
Impedance

(–)

Series Wiring

(+)

4 Ohms

8Ohms Nominal Impedance

(–) 4 Ohms

3.2 Signal Sources

The low level preamp outputs of any radio/tape deck, CD player or preamp/equalizer so equipped can drive the GTS300 or GTS600. The gain controls of the GTS300 or GTS600 are used to match the amplifier’s input sensitivity to the output voltage of the source. This matching is important to keep noise low and is explained in the “Adjusting the Gain” section of this manual.

Thanks to Universal Interface Circuitry, the GTS300 or GTS600 can also be connected to power amplifiers, radios or equalizers that are equipped with only speaker outputs by connecting them through the speaker level input connector. Inside the GTS300 or GTS600, the speaker-level and preamp-level inputs are connected through a mixing circuit, which allows them to be used simultaneously. Therefore a low level source, such as a CD player equippe with a volume control may be connected to the preamp- level inputs at the same time as a powered radio/tape unit is connected to the speaker-level inputs. This provides a higher performance alternative to an FM Modulator connection when you wish to add CD capability to a factory casette stereo. Switching from one source to the other is as simple as turning the desired source on and turning the undesired one off – no additional switches or relay connections are needed.

4. Wiring

Proper wiring of the GTS300 or GTS600 and the associated

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