triggered the thermal protection. Turn off the unit, and cool as best as the situation allows.
(DO NOT use cold liquids for this purpose!) If there is still no output, it may help to read the
owner’s manual completely.
Hum or Buzz:
This can be AC outlet related, try plugging the Impulse 500P Subwoofer into a different AC
outlet. Sometimes, if a different circuit (breaker) is used for the mixer and the Impulse 500P, it
can cause hum problems. Check to make sure that shielded cables have been used to get
the signal to the Impulse 500P’s inputs. Speaker cables with 1/4" or XLR plugs will be very
prone to hum.
Check to make sure light dimmers are not on the same circuit as the Impulse 500P or the
mixer (or any source devices). If light dimmers are in use, then it may be necessary to turn
them full on or full off to eliminate or reduce hum to tolerable levels. This is an AC wiring/light
dimmer interference problem, and not the fault of the Impulse 500P Subwoofer.
Distorted or Fuzzy Sound:
First, make sure the mixer (or signal source) is not clipping or being overdriven. This can
sometimes occur when the level control (6) on the Impulse 500P Subwoofer has been set too
low (too far CCW), and it takes a lot of signal to drive the unit to full power.
Make sure the input plugs are fully seated in the input jacks (5) on the rear panel of the
Impulse 500P Subwoofer.
Check to see that the proper inputs are being used (5), and not the high pass filter output (7),
for line level input signals. Make sure that a power amp has not been plugged into the input
jacks of the Impulse 500P Subwoofer.
If an extension cord is being used to provide the AC power to the unit, is it of sufficient current
capacity and not also being used to supply power to any other units? See GETTING AC
POWER TO THE IMPULSE 500P Subwoofer for details.
The Impulse 500P Subwoofer has built-in EQ to extend and smooth the natural response of
the speaker in the system. Bass boost and infrasonic roll off have been applied, and the
system has a nominally flat response, and should require little, if any, additional EQ. If
excessive additional bass boost or EQ boost have been added externally to the Impulse
500P, it may cause premature overload at high SPL’s. Try backing off of any external (mixer,
rack Equalizer) EQ and see if that clears up any tendency to distort.
Finally, realize that even though the Impulse 500P Subwoofer is an extremely powerful and
high output unit, it does ultimately have limits, and it may need additional powered units to
provide enough sound output or coverage. In this case, try turning the mixer levels down a
little to see if that clears things up.
If, after checking all the listed things to check, and anything else you can think of to check
safely, and the system still exhibits problems, carefully note all conditions and check with your
Peavey dealer for advice.
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