Manual-4
SEQ 30S & 30L CONNECTION
Exactly
where
you install your SEQ 30 into a sound system
significantly affects such things as noise, system headroom, com-
pressor/limiter performance and other factors influencing overall
sound quality. Both
what
and
why
you are equalizing determines
where
you install it.
WHAT AND WHY
Tone contouring is accomplished primarily by ear. This you
know how to do. Be careful though, not to boost too much bass.
Be aware that the SEQ 30 is capable of boosting signals up to
12 dB (4 times as large!)—a level at which great care should be
taken to prevent seismic disturbances. Optimal gain setting is in-
dicated by the +4 dBu indicator lighting occasionally, while the
OL indicator does not light.
The SEQ 30 can be used to align crossovers and flatten
speaker response. The best way to “see” what your sound system
is doing, is to use a realtime analyzer, such as the Rane RA 30.
A ⅓-octave realtime analyzer is an accurate means for setting a
⅓-octave equalizer properly.
WHERE
For tone contouring, the equalizer may be used at any point
in the signal chain, such as insert loops in a mixer to equalize a
single instrument, sweeten a tape recording, etc. When an equal-
izer is used for acoustical correction, the equalizer should be
one of the
last
pieces of gear in front of the amplifiers and active
crossover. Here are a few
general
guidelines to decide where to
install the EQ in the system.
Downstream of the Compressor
Since system EQ is aimed at controlling
acoustic
problems,
install it
after
any compressor, which is designed to operate on
electrical signal. For one thing, the equalizer slider settings will
change in each room location, which in turn affects the control
voltage and threshold responses of the compressor, rendering it
inconsistent. Secondly, large amounts of boost often cause tone
differences by causing some frequencies to limit or compress
before others.
After any System Gain
The best configuration is: mixer, compressor/limiter, equal-
izer, crossover, then power amplifier. Whenever headroom
allows, try to take all the gain at the mixer, and run unity levels
from then on. This also gives better noise performance through
the system. Connect the SEQ 30 before the amplifier or active
crossover. Take any required line gain before the SEQ 30. Avoid
taking a lot of gain in the crossover or power amps as this may
create noise problems. The SEQ 30 operates at unity gain with
the INPUT LEVEL control at the 0 dB center detent when slid-
ers average to center (0 dB). You can test this with the EQ BY-
PASS switch—adjust the INPUT LEVEL control so that volume
does not change when switching between Active and BYPASS.
For details, read “
Setting Sound System Level Controls
” provided
later in this booklet or at the Rane website.
Send/Receive Loops
Mixers, mixer/preamps and the like often provide send/re-
ceive loops for additional effects or EQ, and the SEQ 30 works
well in this situation. Just be sure to keep input trim or gain
controls turned up as far as the mixer input headroom will allow,
to avoid taking excessive gain downstream and creating noise
problems.
OPERATING INSTRUCTIONS
The SEQ 30 is an accurate, professional quality instrument
capable of precise equalization down to a fraction of a dB. You
can expect several advantages from your constant-Q equalizer
over conventional designs: Moving one slider will not affect
neighboring filters as much, so you won’t spend time re-adjusting
sliders (we call this “equalizing the equalizer”). You’ll be able to
obtain better feedback control without losing sound quality. All
sliders maintain smooth, consistent and accurate calibrated con-
trol over filter levels. Because of this, the overall EQ adjustment
process is significantly easier and more effective.
Equalizing a sound system by ear is
very
difficult to achieve
successfully, especially in a timely manner. Although the hu-
man ear is very sensitive, it is
not
calibrated, nor consistent, and
frankly the odds
against
a well behaved, clear sound system are
very great when tuned by ear. Most people know when a sound
system doesn’t sound good, unfortunately they just can’t tell
exactly
why
and
where
it’s not right.
Because of this, we strongly
recommend the use of a realtime analyzer to properly equal-
ize your system.
A realtime analyzer helps you quickly achieve things nearly
impossible by ear: flatten speaker response, minimize feedback,
reduce room resonance and achieve accurate crossover align-
ment. In most cases, simply “normalizing” or “flattening” a
sound system is a surprisingly drastic improvement, but
don’t stop
there
:
Remember this Rane proverb: “Look, don’t stop, and listen.”
Once you have aligned the system by
looking
at the analyzer,
don’t stop
at this point.
Listen
to the music program and make
additional adjustments to suit your taste, the type of music and
your audience. Fatten the bass, sweeten the highs, brighten the
mids. Since you are starting from a “tuned” system, your ear will
not be fooled into thinking bass is too high when actually mids
are too low, or that highs are too weak when really the mids are
too strong.
Fact: analyzers don’t have good taste—people do.
Analyzers
consistently and accurately “tell it like it is,” but ultimately, per-
sonal judgment determines what sounds good or appropriate for
the program material. In fact, final optimum EQ settings, made
after
analyzer testing, will vary greatly depending on the type of
music, sound pressure level, size of the venue and disposition of
the audience.
Conclusion:
To consistently obtain the best sound from your
system, use an analyzer and then your ears, in that order.
The
analyzer supplies the consistency and calibration while your ears
supply the good taste. We of course recommend the very fine and
affordable Rane RA 30 Analyzer.
All features & specifications subject to change without notice.107081
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 USA TEL 425-355-6000 FAX 425-347-7757 WEB www.rane.com
