Operation; Feedback Control; Channel Equalization; Large Room Equalization - Phonic iA231F Manual Del Usuario

OPERATION

Feedback Control

In live performance applications, graphic equalization
is almost always applied separately to stage
monitors or foldback systems to reduce the level of
frequencies that would otherwise cause feedback
problems. These problems occur due to peaks in the
frequency response curves of the monitor speaker
system, as well as due to monitor positioning and
sound reflected from the stage walls.
The iA graphic equalizer features a feedback
detection systems that, when activated, will
allow users to recognize problem frequencies by
illuminated LEDs on the VR sliders.
occurs, and if the feedback is audible, simply reduce
the affected frequencies until the feedback becomes
inaudible and/or the LED goes out.
Of course, feedback may be inadvertantly detected
by the device if the signal includes an abundance
of frequencies similar to those of feedback (some
electric guitars, for example). If this is the case,
simply ignore the detected "feedback".
The iA graphic equalizer can be used to provide
some control over moderate feedback problems,
but does not have enough flexibility or resolution to
handle severe situations.
If you find feedback points covering many equalizer
bands and cutting every band doesn't help, then it
would be advisable to reduce the system gain. The
combination of a graphic equalizer for tone control
and a parametric equalizer for feedback control is
highly recommended.

Channel Equalization

Many mixers provide only simple equalization for
individual channels, typically two or three bands. If your
mixer has channel inserts, you can patch your equalizer
into a channel that is being used for something important
and use it to tailor the sound of this channel exactly the
way you need for your setting.
8

Large Room Equalization

Large venues tend to suffer from multiple reflections
with long delays and reverberation times; all of
which lead to reduced intelligibility and a generally
muddy sound. As sound travels long distances
through the air, high frequencies are attenuated
more than low frequencies. In general, a large room
benefits from some low frequency roll-off and some
high frequency boost. Therefore, reducing the low
frequency output may produce real advantages in
buildings made from concrete or stone, where much
of the bass is reflected rather than absorbed. Also
rolling off the high frequency end above 5 kHz may
When this
also contribute to a more natural sound. Depending
on the individual sound system and the environment,
the shape of the optimum house curve will vary and
a degree of experience is needed in order to achieve
the best result.

Quick Tips

Using the low cut filter will remove stage rumble and
various low-frequency feedback signals that may
cause your sound to lose it's crispness. Audition a
few LCF settings before deciding which is best for
you.
Be sure to choose the optimal position for your
speakers, because no matter how much equalization
you have, if your audio is bouncing off walls and
floors, it can still sound dull.
Using a Personal Audio Analyzer with an EQ setting
function will allow you to determine how to set your
equalizer up without a fuss. In live gigs, it is strongly
suggested that this measure be taken to get the
most out of your audio.
iA231F / iA231FD