EQ231G User Manual
6
c) Elimination of "sibilance"
Sibilance is the noise which occurs when someone is speaking who either has a "hissy"
voice or who is using words with the letter "s" in them, e.g. "Pressure", "Rose", etc. This
can become annoying to a listener and the graphic equaliser can be used to overcome
this problem by either removing or reducing the offending frequency.
d) Elimination of "proximity effect"
Cardioid microphones usually have a low frequency emphasis, which in certain
situations can present problems. For example, speech over a public address system
not being fully intelligible. The graphic equaliser can eliminate this by reducing or
removing the unwanted frequency.
e) Sound-effects
By using the graphic equaliser creatively a sound may be completely changed and
effects obtained. The most common sound effect created in this way is the "telephone
voice" which can make an expensive studio microphone sound like a telephone handset.
f) Reduction of feedback
In many auditoriums, a graphic equaliser may be used to increase the overall sound
level without feedback. Having identified the frequencies which "ring" the most in a given
auditorium, the graphic equaliser is then used to reduce the offending frequencies,
enabling the overall gain to be increased.
g) Intelligibility
A graphic equaliser may be used to make a speaker appear more intelligible to his/her
audience. Usually, the equaliser is compensating for deficiencies either in the sound
system, or with the room characteristics.
5.2. A word of caution
The graphic equaliser is a powerful tool, but it should be noted that it cannot cure
everything. Very often there are other effects such as reverberation and phase shift to be
taken into account when faced with a "poor" sound. It should be noted, for instance, that
different frequencies are attenuated differently as they travel through the air and so a
true "flat" response may not always work for a given room. The human ear is probably
the best arbiter in most cases.
Extreme filter settings are to be avoided unless you are creating a sound effect. The
introduction of phase shift, which accompanies such settings, will probably do more to
compound the problems, than cure them. Usually the response shown "graphically" by
the front panel should be generally smooth, otherwise the resultant sound will appear
synthesised or "unreal".
Also note that whilst the filters are designed not to interact, there will always be a
combining effect between adjacent filters, so when equalising a room it will be
necessary to analyse, adjust, analyse again, and adjust further until the correct
response is obtained.
Finally, it should be observed that, as with all tools of this nature, it is only experience
and practice that will enable you to employ the unit to its best effect.