Fishman Loudbox Performer User Manual

15
About Acoustic Feedback
Feedback usually occurs in the lowest octave of your instrument, generally with
two notes about a half step apart. The lower type of feedback (cavity resonance)
starts when the sound pressure coming out of the speakers excites the resonant
air chamber inside your instrument. We have found that it is effective to tune
out an instrument’s cavity resonance feedback with the Anti-Feedback (notch
filter) in the Loudbox Performer. For acoustic guitar this occurs at G# on the low
E-string, or at about 100Hz. Turn the Anti-Feedback knob to about 11 o’clock to
dial out this resonance. Note that the circuit can be effectively defeated by mov-
ing the dial to the Off (7 o’clock) position.
The higher range of feedback (top resonance) usually starts about a half or whole
step above cavity resonance of the instrument. Top resonance feedback
happens when the sound pressure coming off the speakers excites the resonant
frequency of the soundboard of your instrument. For acoustic guitar, this occurs
at A and above on the low E-string. Push the Phase switch in and out until you
find the position that subdues top resonance feedback.
Lower
Feedback Range
(E to G#)
Upper
Feedback Range
(A and above)
Anti
Feedback
Phase

Fishman Loudbox Performer Specifications

General

Enclosure Material	Wood
Power Output	180 watts
Speaker Size	8" woofer and 1" tweeter
Channels	2
Effects	Reverb, Chorus, Flanger, Delay, Echo, Slap Echo
Inputs	2 x XLR-1/4" combo, 1 x 1/8" (aux)
Outputs	1 x 1/4" Line Out, 1 x XLR Direct Out
Phantom Power	Yes
Footswitch I/O	1 x 1/4" (for optional footswitch)
EQ	3-band EQ