Manual-4
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 TEL (425)355-6000 FAX (425)347-7757 WEB http://www.rane.com
OPERATING INSTRUCTIONS
Once the PE 15 is properly installed, it is then time to
twist some knobs. Power up the system in the normal fashion,
always turning on the power amplifiers last. It is good
practice to start at the head of the system, turning on any
sound sources and mixers first, equalization devices next, and
finally power amplifiers. Following this power-up sequence
minimizes the change of high gain stage turn-on transients
finding their way to the loudspeakers. It is very wise to start
with the PE 15’s MASTER CONTROL all the way down and
the five LEVEL controls set to their center detents. This
eliminates the possibility of surprises encountered by having
15 dB of boost centered at a feedback frequency!
With either a canned or live source applied, advance the
MASTER CONTROL until normal system gain is achieved.
Now you are ready to make some adjustments. A detailed
discussion on room equalization lies outside the scope of this
manual; however, a few words can’t hurt.
Experienced sound people almost always use some sort of
realtime analyzer (RTA) as an aid in setting equalization. An
RTA allows you to see the frequency response changes as you
do them. This is invaluable in achieving better sound.
As a notch filter, the PE 15 works very well in increasing
system headroom by attenuating system peaks that create
feedback problems. The obvious goal in notching is to
remove only the problem areas and nothing else. With this in
mind, it is always a good idea to first try to notch out feed-
back with the BW controls set to their full counterclockwise
positions. The acoustic resonances causing feedback are
generally so narrow that a filter bandwidth set at .03 (
1
/
30
)
octave easily cures the problem. To chase down the feedback
frequency, start with the filter LEVEL control set to its full
-20 dB position. With the BW still set to minimum, tune the
FREQ control until the feedback goes away. It shouldn’t take
too much fine tuning to find the center of the resonance. Once
you have achieved stability, advance the MASTER CON-
TROL until the feedback starts to reappear, then back it down
slightly. If a -20 dB cut won’t cure the problem, the resonance
is extreme and must be dealt with in other ways. For example,
move the speakers or the mics; hang some drapes; move some
walls; burn down the building; or simply unplug the system—
something must give!
REGARDING PE15 NOISE
You may experience noise when using this unit with one
or more bandwidth (BW) controls set to the narrowest (.03)
possible setting. This is the
noisiest
possible setting. The most
usual use for this setting is deep notching. e.g. for eliminating
a specific frequency, such as problems caused by feedback or
other oscillations. Most often only one filter is required. It
should also be noted, there is a trade off between noise and
desired results, when using narrow bandwidth notching. For
example, where the system correction achieved out weighs
the noise levels generated by the required setting.
PE 15 CONNECTION
The PE 15 is compatible with all line-level (-10 dBV and
+4 dBu) interfaces and products. However, guitars, micro-
phones and other low level products
must
be preamplified
before connecting to the PE 15.
The proper connection of this unit to a system is a
relatively simple matter, the specifics of which may vary
greatly depending on the application. Use a PE 15 anywhere
line-level frequency contouring is required. This includes live
sound reinforcement systems, recording studios, clubs, etc.
The most common location to insert a parametric equal-
izer is immediately preceding the active crossover or power
amplifier. This provides the means to correct loudspeaker
deficiencies and other acoustic corrections required in any
system for high quality reproduction. Many systems employ
both a graphic and parametric equalizer connected in series.
The graphic being used to correct for acoustic anomalies,
while the parametric helps source correction, loudspeaker
compensation and feedback control. In these situations, the
order of placement is not critical, however the PE 15 does
feature true actively balanced differential outputs which may
be a consideration in installations requiring very long cable
runs between the equalizers and the power amplifiers or
crossovers.
The ¼" TRS and XLR INPUT connectors are wired in
parallel and are actively balanced. These Inputs are provided
primarily to give the user a choice between two types of
connectors.
They will not sum from two different sources.
For
further information on this subject, please consult the
RaneNote titled, “WHY NOT WYE?” (available from the
factory or the Rane web site). The two Inputs may be used in
a daisy chain application where the Input to the PE 15 also
must feed another piece of equipment.
The outputs of the PE 15 also provide the choice between
¼" TRS connectors and XLR variety. They also are wired in
parallel and are actively balanced. Both Outputs may be used
simultaneously.
All XLR connectors used by Rane are wired per the IEC/
ANSI/AES standard as follows: pin 2 positive, pin 3 negative
and pin 1 chassis ground.
Unbalanced use of a PE 15 requires you to take some
particular steps in wiring. On the Input, use either a mono ¼"
connector (no ring), or short pin 3 to pin 1 and drive pin 2 for
XLR connectors. On the Output leave pin 3 open and take the
signal from pin 2 (hot) and pin 1 (chassis ground). When
using ¼" plugs, the preferred arrangement is to use a tip-ring-
sleeve version and leave the ring open. Alternatively, a mono
plug may be used.
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