MTX Audio RT202 RT404 owner manual ❺ ❶ ❹ ❻ ❸

AMPLIFIER OWNER’S MANUAL

1.RCA Input Jacks – These RCA input jacks are for use with source units that have RCA or Line Level Outputs. An independent set of jacks are provided on the RT404 for front and rear stereo inputs. A source unit with a minimum level of 200mV is required for proper operation. The use of high quality twisted pair cables is recommended to decrease the possibility of radiated noise entering the system.

2.Input Select 2CH/4CH – This switch, found on the RT404, is used to match the amplifier’s input to the source unit’s output so all four channels of the amplifier are driven. If your source unit has 2 outputs (left and right) connect them to the amplifier’s front channel inputs, and place the input select switch in the 2CH position. If your source unit has 4 outputs, (left front, left rear, right front, right rear) connect them to the amplifier inputs and place the input select switch in the 4CH position. In the 4CH position, the fader on your source unit will operate.

3.Speaker Level Inputs – This input will allow the amplifier to operate from source units with speaker level outputs. Output speaker leads from the source unit should be tied directly to the wire harness provided with the amplifier.

Wire harness color codes:
Grey/Black = Source unit right negative (-)	White/Black = Source unit left negative (-)
Solid Grey = Source unit right positive (+)	Solid White = Source unit left positive (+)

With the Smart-Engage™ auto-turn-on circuit, a remote turn-on wire is not necessary when connecting the speaker-level input wire harness to a high powered source unit. The amplifier will automatically turn on when music is received.

4.RCA Output – These RCA outputs allow for a signal to be sent to other amplifiers in a daisy-chain configuration. The RCA outputs on all Road Thunder series amplifiers will send a full-range signal to additional amplifiers.

5.Gain Controls – These controls are used to match the input sensitivity of the amplifier to the particular source unit that you are using. The controls are factory set to 1Vrms. Note that the RT404 has a separate gain control for front and rear channels.

6.Crossover Select – This switch controls the type of crossover configuration that you desire. Road Thunder series 2-channel amplifiers include a defeatable 18dB/octave, 85Hz crossover that is high pass/low pass or full range selectable. The RT404 four channel amplifier includes a defeatable 18dB/octave, 85Hz crossover that is high pass or full range for the front channels, and a high pass, low pass or full range for the rear channels.

Input Panel Layout

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			SPEAKER FRONT IN		SUM OUT	REAR IN SPEAKER
			LEVEL				LEVEL
			INPUT				INPUT
FRONT	AMP	RCA	FRONT		L	L	REAR	AMP	REAR
GAIN	X–OVER	INPUT						X–OVER	GAIN
					R	R
❺	FR HP	2CH 4CH		❶	❹	❶	❸	LP FR HP	❺
	❻	❷ ❸						❻
			R– L–				R– L–
			R+ L+				R+ L+

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