Installation ~ LCD Programming

11

Inputs

There are four main submenus under the Inputs menu tree: Mic/Line In, Aux In, 4

Wire In, and From Telco (see Figure 2.7).

Mic/Line In

Gain Adjust. This adjusts the Mic/Line In submenus, including the level for the

Input gain (ranging between -20dB and 20dB). The default setting is 0dB.

Mic/Line Input. This input defaults as a line-level input (0dB gain) but can be switched to a mic level input (55dB or 25dB gain).

Mute. This parameter mutes the input channel.

Phantom Power. Defaults with 24V phantom power disabled, but may be switched on to accommodate input devices requiring phantom power.

AGC. The input can use automatic gain control (AGC). This feature keeps softer and louder talkers at a consistent transmit level. This feature is disabled when shipped from the factory. The target gain is 0dB and adjusts at 2dB per second. The AGC start adjustment is -20dB, but will adjust only +6dB. Adjustments will not be made at .5dB on either side of the target (0dB).

High-Pass Filter. A high-pass filter may be selected on the Mic/Line input to reduce unwanted noise. The filter has a break frequency at 250Hz, and -3dB down at 200Hz, then rolls off at 6dB per octave. This feature is disabled when shipped from the factory.

Echo Canceller. Activate or deactivate the echo cancellation feature for this input.

Factory default is On.

NLP Adjust. Non-linear processing (NLP) has four settings: soft (6dB), medium (12dB), aggressive (18dB), and Off. NLP adds more echo cancelling “horsepower” in difficult acoustical environments. Use care when increasing NLP, because of the corresponding trade-offs which can include suppression and half-duplex operation. Factory default is Soft.

Aux In, 4-Wire In, and From Telco

Gain Adjust. This adjusts each Input gain (ranging between -20dB and 20dB) in conjunction with the LCD readout and the LED bar graph. The default setting is 0dBu.

Mute. This parameter mutes the input channel.

Technical Services Group ~ 1-800-283-5936 (USA) ~ 1-801-974-3760

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ClearOne comm GT1524 operation manual Inputs, Mic/Line, Aux In, 4-Wire In, and From Telco