About Compression - Hartke KILO Mode D'emploi

Kilo • 1000 Watt Bass Amplifier

About Compression

The dynamic range of a sound is the difference between its loudest and softest levels.
For example, as you play your bass, you'll probably find that some notes (such as notes
played on the upper frets of the lowest string) are considerably louder than others.
The function of the compression circuitry in the Kilo Bass Amplifier is to reduce overall
dynamic range by automatically reducing the level of the loudest sounds you play so
that they are closer in level to softer ones. The end result is a smooth, even sound.
The front-panel COMPRESSOR control determines the amount of
compression (peak signal reduction) by adjusting the threshold.
Threshold is the limit above which compression is applied. As you
turn the COMPRESSOR control clockwise, the threshold level is
lowered. The compression ratio is set to around 2:1, which means that
any input signal over the threshold level will be halved.
The Kilo compression circuit follows the incoming signal, and will
adjust the compression ratio down when you play notes with fast attack to avoid
"squashing" your sound. This is useful when playing fast staccato passages, as it will
cause all the notes to sound at the same level, even if the signal is above the threshold
level.
The Kilo provides a front-panel compression LED indicator that visually indicates when
the audio signal crosses the threshold level and activates the compressor circuit. When
unlit, no compression is being applied. When the indicator lights red, compression is
being applied to the incoming signal.
Compression has three main uses. First, as described above, it "evens" out the notes
played by your bass so that they all are at virtually equal levels. Second, it adds "punch"
to a sound. Since all levels are nearly the same, you can play with greater force without
worrying about the loudest notes distorting. Finally, it serves to protect your loud-
speakers from damage as a result of brief (transient) high output levels, which might
otherwise be caused by slapping, finger-popping or other performance techniques.
Whether or not you need to use compression with your Kilo will be a matter of per-
sonal taste and playing style. Experiment and see if you like the effect. If you usually
play at low volume levels, you'll find that even with the COMPRESSOR knob turned
up, the compression circuitry may have no audible effect. In general, if you don't need
compression, leave it off.
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