About Crossovers
The idea of a 'two way' speaker (which is what most 'full range' speakers are) is usually
that the speaker cabinet houses two separate actual speaker drivers. It is common for
one to be dedicated to reproducing High frequencies and the other to be dedicated to
reproducing Low and Mid range frequencies. In order to make this work it is necessary
to split the incoming audio signal in such a way that only High frequencies are sent to
the High Frequency tweeter and only Low/Mid frequencies arrive at the Low/Mid driver.
The device used to split the signal is called a 'Crossover'. It is common when assembling
a more powerful PA system to have either a 'three way' system consisting of 3 separate
speaker cabinets (1 each for Low, Mid & High frequencies) or a two way system where
several full range speaker cabinets are augmented by an additional Sub or Bass speaker.
In such set ups it is also necessary to employ Crossovers to divide audio signals so that
the right PA system components receive only the right audio frequencies.
[13] Sub Woofer Crossover switch
- use this switch to turn the channel 3 Crossover
on/off.
[14] Sub Woofer Crossover Frequency control
- when the Sub Woofer Crossover is on,
use this control to adjust the Crossover Cutoff Frequency. Only frequencies below the
Crossover Cutoff Frequency will be sent to channel 3.
[15] Low Cut Filter controls
- use this to switch the Low Cut Filter on/off to remove low
frequency rumble etc to deliver an uncluttered low/mid sonic response.
There are 3 positions; Bypass where the Low Cut is not active, 30Hz where all
frequencies below 30Hz are removed, 50Hz where all frequencies below 50Hz
will be removed.
[16] Limiter switch
- use this to switch the built in Limiter circuit on/off. When in the on
position the audio signal will be automatically prevented from exceeding the maximum
signal level beyond which clipping (distortion) will occur and the Peak LEDs will light.
[17] Ground Lift switch
- When using Unbalanced audio input connections you may, in
some circumstances experience problems with persistent hum. This can be caused by
an 'earth/ground loop'. Using this 'ground lift' switch disengages the ground (aka earth)
connection from the mains power to the amplifier and can help in some circumstances.
The problem is rare with correctly configured Balanced audio connections.
You will find loads more advice and information about setting up Kam audio equipment
within the Tuition area at www.kam.co.uk.
Thank you for reading these guidelines and enjoy your Kam KXT amplifier!
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