Mackie M2600 BI-AMPLIFIEDAND TRI-AMPLIFIEDSYSTEMS

BI-AMPLIFIED AND TRI-AMPLIFIED SYSTEMS

Most speaker systems in use today are of the two-way or three-way variety. Cone speakers are good at reproducing low and mid-range frequencies, but not high frequencies. Likewise, compression drivers are good at reproducing high frequencies, but definitely not low frequen- cies. This is why two-way, three-way and even four-way speaker systems were developed — to improve the efficiency of each individual driver by requiring it to reproduce only the frequencies that it reproduces best.

One method of accomplishing this is through the use of a passive crossover network between the amplifier and the speaker(s). Often the passive crossover is built into the cabinet along with the various drivers. The crossover divides the high-level speaker signal into frequency bands, which are then directed to the appropriate driver. There are some drawbacks to this method, however. The passive crossover adds reactance to the load that the amplifier sees, which can affect the damping. Power is wasted as heat across the resistors in the crossover, reducing the amount of amplifier power available to the drivers themselves.

			FR SERIES
	POWER AMPLIFIER
		(STEREO MODE)
FROM SIGNAL SOURCE	CH 1		CH 1	+
(MACKIE MIXING CONSOLE)	IN		OUT	–
FROM SIGNAL SOURCE	CH 2		CH 2 –
(MACKIE MIXING CONSOLE)	IN		OUT +

Passive Crossover System

Biamplified and triamplified systems use separate power amplifiers to power each individual low-frequency and high-frequency driver. An electronic crossover (a.k.a. active crossover) is located between the signal source and the power amplifier. The advantages of this method include:

•Increased headroom available from each amplifier, since they’re amplifying only a portion of the entire audio spectrum.

•Improved damping factor because the amplifier output is connected directly to the driver.

•Improved efficiency because there are no passive resistors to dissipate heat; and

•Flexibility to choose the optimum cross over frequency and crossover slope for the individual drivers in the system.

The M•2600’s internal crossovers are electronic (active) and allow biamplification above and below a user-selectable crossover point of 60Hz, 90Hz, or 120Hz. See the application diagrams on pages 13-16.

TWO-WAY SPEAKER CABINET

HIGH-LEVEL	HIGH FREQUENCIES
PASSIVE
	TO TWEETER
CROSSOVER
	LOW FREQUENCIES
	TO WOOFER

TWO-WAY SPEAKER CABINET

HIGH-LEVEL	HIGH FREQUENCIES
PASSIVE
	TO TWEETER
CROSSOVER
	LOW FREQUENCIES
	TO WOOFER

FR SERIES

FROM SIGNAL SOURCE

POWER AMPLIFIER

(MACKIE MIXING CONSOLE)

(STEREO MODE)

TO HIGH-FREQUENCY

CH 1

+

TWEET

LOW-LEVEL

AMPLIFIER

INPUT

CH 1

3-WAY ACTIVE

OUT

–

CROSSOVER

TO MID-FREQUENCY

CH 2

CH 2 –

INPUT

AMPLIFIER

OUT +

MID

FR SERIES

FR SERIES

POWER AMPLIFIER

FROM SIGNAL SOURCE

POWER AMPLIFIER

(BRIDGE MODE)

(MACKIE MIXING CONSOLE)

(STEREO MODE)

TO LOW-FREQUENCY

CH 1

+

TO HIGH-FREQUENCY

CH 1

+

TWEET

AMPLIFIER

INPUT

CH 1

LOW-LEVEL

AMPLIFIER

INPUT

CH 1

OUT

–

2-WAY ACTIVE

OUT

–

CH 2 –

WOOF

CROSSOVER

TO LOW-FREQUENCY

CH 2

CH 2 –

AMPLIFIER

INPUT

OUT +

OUT +

WOOF

Biamplified System with External Active Crossover Triamplified System with External Active Crossover

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