5dB

dB

0dB

Level,

–5dB

 

 

–10dB

 

–15dB

1Hz

10Hz

100Hz

1kHz

10kHz 20k

Frequency, Hz

Low Cut Filter Frequency Response

In order to match the output bandwidth with your particular speaker system, the M•2600 amplifier has a tunable LOW CUT FILTER. The frequencies are marked along the knob’s travel :

•Fully counterclockwise, the frequency is below 10Hz, effectively bypassing the filter.

•Center detent is 35Hz and labeled TYPICAL, since precious few woofers actually go below that.

•3/4 of the way up is labeled STAGE MONI- TOR, 100Hz, perfect for stage monitors (they seldom reproduce below 100Hz; besides, it prevents low-frequency “leakage” into the house).

•Fully clockwise is labeled 170Hz.

So, grab your woofer’s spec sheet and find the low roll-off spec. Then set the M•2600’s LOW CUT FILTER at the same frequency. If you do this correctly (and make sure the meters are happy), you’ll never again see your woofer moving sporadically without audible signal. Your system will play louder and cleaner, and you may never blow another woofer again!

CROSSOVER SWITCH

This three-way switch allows you to set the crossover point of the internal CROSSOVER to either 60Hz, 90Hz or 120Hz. This affects two things:

•The THRU output , if the THRU switch is set to LOW OUT or

HIGH OUT.

•The SPEAKER OUTPUTS , if the

OUTPUT APPLICATION switch is set to LOW OUT. The amplifier then plays the frequency range below the crossover point.

Note: The LOW CUT FILTER affects

both the THRU outputs and the SPEAKER OUTPUTS in the cases above.

AMP MODE SWITCH

This three-way switch, along with the OUTPUT APPLICATION switch, determines what kind of amplifier you want the M•2600 to be (or not to be — what was the question?).

The AMP MODE switch determines the input signal routing within the M•2600 amplifier. Shipped from the factory, the switch is set to STEREO. This is correct for about 90% of the applications using an amp like this (hence the TYPICAL indicator near it). But you may be in the 10% bracket, requiring special input routing within the amp.

AMP MODE should always be configured before operation, with the amplifier turned off.

1 CHANNEL

INPUT

 

 

 

 

 

CROSSOVER

 

BALANCED

LOW CUT FILTER

 

 

 

OR

 

 

 

TYPICAL

60Hz

90Hz

120Hz

UNBALANCED

 

 

 

 

 

 

 

35 Hz

 

 

 

 

 

 

R

STAGE

 

 

 

 

O

F

E

MONITOR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

W

 

 

 

 

 

 

B100 Hz

U

S

OFF

170 Hz

 

AMP MODE

STEREO

MONO BRIDGED

TYPICAL

 

 

CH's

 

SUMMED

OUTPUT APPLICATION

 

FULL

LOW OUT

 

RANGE

(SUB WOOFER)

CROSSOVER

60Hz

90Hz

120Hz

 

 

 

 

CHANNEL 2

 

 

 

 

INPUT

LOW CUT FILTER

BALANCED

 

 

TYPICAL

OR

 

 

UNBALANCED

 

 

 

35 Hz

 

 

 

R

STAGE

 

O

F

E

MONITOR

 

 

 

 

 

 

 

O

 

 

 

 

W

 

 

100 Hz

 

U

 

 

B

 

 

 

 

S

 

 

 

 

OFF

170 Hz

 

THRU

THRU LOW HIGH OUT OUT

IN

SWITCHED OUTPUT

OFF

ON

TYPICAL

LIMITER

(CH1 & CH2)

THRU

HIGH LOW THRU

OUT OUT

IN

SWITCHED OUTPUT

25