ELIMINATING FEEDBACK
Feedback is usually one frequency or a narrow frequency band that recirculates from a microphone (or
pickup) through the P.A. or monitors and then back through the microphone again. The result is a high-
pitched ringing or squealing sound.
Here's a way to eliminate it, using the Fishman Dual Parametric D.I.:
Plug your pickup-equipped instrument or microphone into the Dual Parametric D.I., and the D.I.into your
mixer. Turn one Band off and set the other's boost/cut to 0dB and its Octave knob to .5. Then raise the
level of the mixer until the speakers squeal. Backing off a little bit, just below the feedback point, turn the
EQ's boost up about halfway and slowly turn the Frequency knob up until the squeal begins. Now,
change the knob from boosting to cutting to cut the feedback. Raise the volume a bit more, and when
you start to hear ringing again, adjust the octave knob to a tighter range, closer to .015 and then cut a
little bit more. That should do the trick.
REDUCING “THUMP” IN ACOUSTIC INSTRUMENTS
Some acoustic instruments, especially large-bodied acoustic guitars, have a lot of "thumpiness" in their
low range, most often caused by bumping the body with your hand. Through an amplifier or P.A. they're
loud and annoying. Here's how to reduce it:
Plug your pickup-equipped instrument or microphone into the Dual Parametric D.I., and the D.I. into your
mixer. Turn one Band off and set the other's boost/cut to its 9 o'clock position and its Octave knob to .5.
Set the Frequency Multiplier Switch to its leftmost position, "X 1." Turn the Frequency knob fully counter-
clockwise. Now start making thumps with your hand-tapping with the heel of your hand or gently with
your index finger. As you tap, slowly turn the Frequency knob clockwise, listening to the effect that the
Dual Parametric D.I. has on the sound. If you have a hard time hearing where the thump is most promi-
nent, set the Octave knob to .015 and set the boost/cut knob to its 3 o'clock position. Start tapping and
turn the Frequency knob. When you hit the most prominent thump frequency, the thump will sound very
pronounced and perhaps even like a weird drum. Continue tapping and turn the boost/cut knob until the
thump is greatly reduced or disappears altogether. Play some notes and/or chords on the instrument to
make sure that you didn't cut out some of the vital suppor t. You may have to experiment with the amount
of cut to strike a balance between keeping your tone intact and reducing the thump.
EQ / PREAMP / DIRECT BOX
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APPLICATIONS
