Klark Teknik U.S.A. Air Compressor DN540 Manual Do Utilizador

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DN540
Operator Manual
29
Appendix A: Application Notes
The compressor of the DN540 can perform various compression styles for different 
applications.
Drums and percussive instruments
Drums require a slow attack time to thicken the sound.  Try the compressor in manual 
mode with high ratios, slow attack, medium release and soft knee.
Stringed acoustic instruments
Acoustic instruments benefit from subtle processing.  Settings that are too aggressive 
can sound unnatural.  For best level control try using auto mode and soft knee, with 
high ratio and the threshold set quite high.  For more control of instrument timbre try 
manual mode set to slow attack and medium release, with a low ratio and the threshold 
set a little lower.  Experiment with the presence accentuation.
Stringed electric instruments
Here the compression process can become an integral part of the instrument’s sound.  
Try aggressive compression on electric bass and guitars.  Use manual mode and hard 
knee set up with fast attack and release on a medium to high ratio (around 3:1).  To 
accentuate the leading edge of sounds, slow the attack a little.
Brass instruments
Compression is useful for thickening thin sounding instruments and compensating for 
less than perfect mic technique.  Try auto mode and soft knee with high ratios (4:1).
Vocals
Try the compressor in auto mode with a ratio of around 2:1, or soft knee with 3:1 ratio.  
Presence accentuation will allow the threshold to be brought much lower — or the ratio 
raised — for increased compression, while retaining intelligibility.
Presence accentuation
Many instruments have a percussive start to notes that are played.  These contain the 
bulk of the signal harmonics that are recognisable and that we use to distinguish one 
instrument from another.  Without this initial attack most instruments sound quite 
similar, and very dull!  Unfortunately this is what tends to happen when they are 
compressed, as compressors capture much of the percussive start and reduce it in level 
more than they reduce the remainder of the sound.  Although it is not as extreme as 
totally removing the start of notes, it still strips much of the harmonic content and 
removes presence from the sound.
This can be corrected by using equalisation to boost the upper frequencies.  However, 
this is dangerous in sound reinforcement because when the instrument is silent and the