Rane RE 27 User Manual

OPERATING / SERVICE MANUAL

REALTIME EQUALIZER

RE 27

QUICK START

If you are familiar with real time analyzers and graphic equalizers, feel free to jump right in. To avoid some of the

lurking sharks read these few tips as a reminder of what it is you already know:

1. FLAT IS NOT BEAUTIFUL. Equalizers have two basic purposes: correction and enhancement. The Rane analyzer
allows you to accurately correct system response to each location. A task very difficult to do by ear. Once this is quickly
done, then you adjust for further sound quality enhancement by ear; only rarely will a system be left in a “flat” condition.

2. USE MORE THAN ONE TEST MICROPHONE LOCATION. Speaker dispersion characteristics vary greatly, from
beamy highs to boomy bass traps. While performing the pink noise test, try at least two different test mic locations and
average the two if they differ.

3. USE ENOUGH PINK NOISE VOLUME TO OVERRIDE BACKGROUND NOISE. There’s no need to run

deafening pink noise levels to EQ a system. Just be sure that no green/red LED responds when pink noise is turned off (if

they do, background noise is causing erroneous readings and pink noise should be turned up higher).

4. USE ±3 dB DISPLAY SETTING FOR LOW FREQUENCY ADJUSTMENTS. The crest factor (peak response) of

true pink noise causes considerable LED flutter in the ±l dB mode, making it difficult to adjust quickly. We recommend
that the ±1 dB setting be used on frequencies below 500 Hz or so; use ±1 dB on the more sensitive mids and highs.

5. THE ANALYZER SECTION CAN BE USED WITH ANY OTHER EQUALIZER. The analyzer section of the RE

27 responds to whatever the microphone picks up. Simply run pink noise through the desired equalizer (channel) and
speaker and use the Rane analyzer to adjust that particular EQ. The RTA is a completely separate instrument.

6. MONITORING -PROGRAM WITH ANALYZER DISPLAY. When the front panel microphone is unplugged, the

analyzer display automatically monitors the output of the equalizer section. Use this feature to identify specific feedback
points by watching for red LEDs during the performance. You can then apply EQ exactly where it’s needed very quickly.
If all else fails, read the rest of the manual.

OPERATING INSTRUCTIONS

Since the RE 27 features a unique form of realtime analyzer, we highly recommend that you read this section before
performing an alignment with pink noise. If you’ve never used an analyzer before, use these instructions on your first
occasion. You’ll be delighted at how simple it really is.

1. SYSTEM HOOK-UP:

the Rane condenser microphone into the front panel RTA MIC INPUT.

the front panel jack: This jack contains DC voltage which may be damaging to other microphones.

you can use another microphone by patching into a send/receive loop on a mixer as described in Rane Note 104 (available on
request).

2. BACKGROUND NOISE CHECK:

like can cause false readings on the analyzer display if the pink noise volume through the speakers is not loud enough to
drown these noises out. Before turning on the Pink Noise, turn up the RTA LEVEL control on the RE 27 until some of the
green and red LEDs respond on the display: now you’re looking at background noise. Slowly turn the RTA LEVEL control
back counter-clockwise until all the green and red LEDs are off, and no background noise is showing on the display. You
will now have to run the pink noise volume through the speakers loud enough to make sure that the RTA LEVEL control is
not turned clockwise (up) from this setting, otherwise the background noise will falsify the readings.

Connect the RE 27 into your system as shown on page 6 or 7, whichever is appropriate. Plug

CAUTION: Do not plug any other microphone into

For special applications

Any background noises such as air conditioners, talking, nearby traffic and the

continued on page 4...

FRONT PANEL DESCRIPTION

1. EQ LEVEL CONTROL: This controls level through the equalizer section and provides up to 6 dB overall gain. Turn

this control down if the overload LED lights up.

2. BYPASS SWITCH: Engage to BYPASS all equalizer sections. The Bypass LED lights whenever the BYPASS switch

is engaged.

3. POWER SWITCH: You’ve probably figured this one out by now...

4. PINK NOISE SWITCH: Engage to activate the built-in pink noise generator.

OFF when not in use. This prevents possible noise bleed-through into the program material.

5. SIGNAL PRESENT INDICATOR: This green LED lights with any input above -20 dBu (.078 volts), even in the

Bypass mode.

6. OVERLOAD INDICATOR: This red LED lights whenever the equalizer signal level reaches 4 dB below clipping.

7. ANALYZER DISPLAY LEDs: Bach red LED lights up when response is too high in that band; green LEDs light

when response is within +3 dB or +l dB of the selected curve; yellow LEDs come on when response is too low.

8. EQUALIZER SLIDERS: Calibrated in 3 dB increments, these sliders provide +12 dB of boost and -15 dB of cut at each

of the IS0 frequency centers.

9. CURVE SELECT SWITCH: The NORMAL position yields a flat response when all LEDs are green. The HOUSE
CURVE changes the response of the display such that the EQ sliders between 400 Hz and 1.6 kHz must be attenuated 3 dB to
obtain green LED response. This reduction in midrange results in a warmer more desirable sound at lower sound pressure
levels.

10. WINDOW SELECT SWITCH: In the ±3 dB position, the green LED in each band lights when signals of that

frequency are within 3 dB above or below the Normal or House curve, whichever is selected. In the ±l dB mode, system
response must be within 1 dB above or below the selected curve to light the green LEDs.

11. MICROPHONE INPUT JACK: Plug only the Rane Microphone into this jack — the DC volt-
age supplied by this jack could be damaging to any other microphone. When the mic is plugged
in, the display responds to whatever the mic picks up; when the mic is unplugged,

display to monitor the output of the equalizer section.

NOTE: Switch the pink noise generator

the jack automatically switches the

12. RTA LEVEL CONTROL: Use this knob to adjust the microphone level (or line level when the microphone is
unplugged) to properly drive the display. This control is accurately calibrated in dB-SPL; any display band whose LED is
green has the sound pressure level indicated by this knob (only with the mic plugged in).

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REAR PANEL DESCRIPTION

1. PINK NOISE LEVEL ADJUST: Use a 1/8" screwdriver to adjust the output from the Pink Noise generator from 0 to

1.2 volts (-4 dBu) to match the input level requirements of the mixer or other equipment.

2. PINK NOISE OUTPUT JACK: This is an unbalanced ¼" jack which supplies pink noise to the sound system.

3. EQ INPUT JACK: This is an automatic balanced unbalanced ¼" input to the equalizer section. Use a mono ¼" plug

for unbalanced operation, or a stereo TRS ¼" plug wired as shown in the diagram below for balanced operation

4. GROUND LIFT SWITCH: This switch provides the ability to separate chassis ground and signal ground. Normally,
this switch should be in the LIFT position. If you are tempted to try moving this switch with your power amplifiers turned
up,

don't be. Always turn your amplifier levels down before changing your grounds around and then bring them up slowly.

5. EQ OUTPUT JACK: This is the automatic unbalanced/quasi-floating output from the equalizer section. Use a mono
¼" plug for unbalanced operation or a stereo TRS ¼" plug wired as shown in the diagram below for use with balanced
equipment (Refer to RaneNote 102 for further information on Rane’s floating output system).

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