simply stops. This causes a sine wave to “square off,” and the average power going into the speaker is roughly double that of a sine wave. Square waves sound awful, and could possibly damage your speakers and/or your reputation.

The LIMITER is especially handy when you’re working with loud output levels. Having the signal spikes (kick drum, for instance) attenuated a bit can actually increase the apparent loudness of the overall mix without diminishing the “power” behind the spikes.

Be Forewarned: With the

LIMITER engaged, you can

still overdrive the amplifier into clipping and cause distortion. It just takes a

stronger signal to do it. So even with the LIMITER turned on, you should still pay attention to the OL LEDs .

SUBWOOFER

Here’s a special surprise: If you bought the M•1400/M•1400i amplifier to power a subwoofer system, you just saved yourself the cost of a crossover! The M•1400/M•1400i amp has an active SUBWOOFER filter built in. You can use it, along with the variable LOW CUT FILTER in a second M•1400/M•1400i, to reproduce the function of a crossover.

5dB

0dB

–5dB

–10dB

–15dB

20Hz

100Hz

1kHz

10kHz 20kHz

Subwoofer Filter

Since most low-frequency energy is monophonic (the same in both channels), the subwoofer circuit takes the signal from both Channels 1 and 2 and sums them together. This summed signal is then directed to both power amplifier output stages. It doesn’t matter whether the AMP MODE switch is set to STEREO, MONO, or BRIDGE, it will sum the inputs when the OUTPUT APPLICATION switch is set to SUBWOOFER.

Here’s how to configure it:

1.Turn the M•1400/M•1400i’s POWER off.

2.Set the OUTPUT APPLICATION switch to SUBWOOFER.

3.Select a rolloff point, via the FREQUENCY

switch: At “125Hz,” you’ll get the low sub-harmonics on up to the audible bass range. At “63Hz,” you’ll get just the lowest frequencies, more to be felt than heard.

You’ll probably want to try this switch both ways.

4.Make sure the LOW CUT FILTER is set to OFF or nearly OFF. If it is turned up above the subwoofer cutoff frequency, the output from the amplifier will be greatly diminished.

5.Connect your cords and speaker cables as

usual (see “Quick Start” on page 4). Set the AMP MODE to either STEREO, MONO, or BRIDGE, depending on your application. (STEREO and MONO operate the same with SUBWOOFER activated).

6.Turn the M•1400/M•1400i’s POWER on. Woof!

1CHANNEL / BRIDGE / MONO

LOW CUT

INPUT

FILTER

 

TYPICAL

BALANCED

OR

35 Hz

UNBALANCED

 

STAGE

 

 

MONITOR

 

 

100 Hz

 

OFF

170 Hz

 

 

CONSTANT DIRECTIVITY

 

HORN EQ /AIR EQ

4.5 kHz

ON

 

 

2k Hz

6k Hz

OFF

 

AIR EQ

 

 

TYPICAL

AMP MODE

STEREO

MONO

BRIDGE

TYPICAL

(CHS SUMMED)

 

OUTPUT APPLICATION

FULL

SUB

RANGE

WOOFER

LIMITER (CH1 & CH2)

FREQUENCY

 

STEREO

125Hz

TYPICAL

ON OFF

63Hz

THRU

THRU

INPUT

CHANNEL 2

LOW CUT

 

FILTER

BALANCED

TYPICAL

OR

UNBALANCED

35 Hz

 

 

STAGE

 

 

MONITOR

 

 

100 Hz

 

OFF

170 Hz

CONSTANT DIRECTIVITY

HORN EQ /AIR EQ

 

ON

4.5k Hz

 

 

 

2k Hz

6k Hz

OFF

 

AIR EQ

TYPICAL

 

 

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