Samson 4060/4120 owner manual Bi-amplification Applications

Bi-amplification Applications

Because the Samson Servo Quad Amplifier actually contains four discrete power amplifiers in a single chassis, it is particularly well-suited for use with bi-amped speaker systems. These systems utilize active crossover networks (sometimes called electronic crossovers) that are specially designed to handle low-wattage line-level signals. As shown in the illustration on the right, the crossover in such a system is placed just prior to the power amplifier in the signal chain.

The circuitry in a two-way active crossover network divides the incoming signal into its high and low frequency components. Those frequencies above a specified crossover point are sent to one discrete output and those below the crossover point are sent to the other. Each output is then connected to a separate power amplifier channel input. In this way, one amplifier powers the loudspeaker’s low frequency drivers (“woofers”) and another powers the loudspeaker’s high frequency drivers (“tweeters”).

The advantage to bi-amping is not only enhanced loudspeaker performance (since each speaker driver is receiving optimized signal) but also greatly reduced distortion. This is because most of the energy in musical signals lies in its low frequency components (next time you’re listening to a piece of popular music, contrast the level of kick drum and bass guitar to the other instruments). When both low and high frequencies are present in a signal, these high-energy low frequency signals can eat up all the available headroom in a power amplifier, leaving none for the higher frequencies. The end result is nasty clipping distortion of the high frequency material. The use of an active crossover network effectively eliminates this problem— in fact, you’ll get cleaner, perceptively louder signal than if you were to use a single higher-power amplifier instead!

Of course, with four amplifiers at your disposal, you can use your Samson Servo Quad Amplifier to bi-amp both the left and right signals in a stereo system. Simply use a stereo active crossover network and route the two left outputs (low and high frequency) to the Servo Quad Amp channel inputs 1 and 2

and the two right outputs to channel inputs 3 and 4. You can then use the front-panel input level controls to adjust the relative levels of each output signal.

	LEFT							RIGHT
	INPUT							INPUT
	SIGNAL							SIGNAL
		ACTIVE CROSSOVER
					NETWORK
		LEFT					RIGHT
	LF		HF			LF			HF
	OUT		OUT			OUT		OUT
	CH1		CH2			CH3		CH4
	IN		IN			IN			IN
			SERVO QUAD
				AMPLIFIER
	CH1 CH2					CH3 CH4
	OUT OUT					OUT OUT
LEFT			LEFT			RIGHT			RIGHT
WOOFER			TWEETER WOOFER						TWEETER
INPUT			INPUT			INPUT			INPUT

10