Manual-11
STEP BY STEP PROCEDURE
A 3-Way mode consisting of High, Mid and Low drivers
is used here as an example. For other configurations, use the
same procedure starting with the highest crossover point and
repeating steps 2 through 5 for each lower crossover point.
NOTE: If you are running two separate Channels on the
crossover, tune up only
one
Channel at a time, using the same
procedure for both.
1. Place the analyzer microphone about 15 feet in front of the
speaker stack and at a height about midway between the
high and mid drivers. Turn all crossover LEVEL controls
fully down.
2. Connect the pink noise source to the INPUT of the cross-
over (or mixer or wherever is convenient). Turn up the
crossover MASTER LEVEL control and the MID OUT
control until noise is heard only from the mid driver at a
comfortable volume.
3. With a healthy but not uncomfortable volume of noise from
the mid driver, set the analyzer DISPLAY LEVEL control
so the LED’s corresponding to the high crossover fre-
quency are reading 0 dB (this would be a green LED at the
crossover frequency with the Rane analyzer). For example,
if your high crossover frequency is 2 kHz, set the RA 27 in
the ±1 dB mode and then adjust the RTA LEVEL control
until the green LED is lit in the 2 kHz band. There...easy.
4. Now press in the MID MUTE switch on the crossover so
that the tone is removed from the mid driver. Without
re-adjusting either the meter or the crossover Input or Mid
Level controls, turn up the HIGH LEVEL control until the
tone coming from only the high driver reads 0 dB (a green
LED at the crossover frequency).
5. Now release the MID MUTE switch on the crossover so
that pink noise is heard from both the high and mid drivers.
Switch the display sensitivity to ±3 dB on the Rane
analyzer (not necessary with full scale analyzers) and
observe the display reading at the crossover frequency:
i. If the display shows a +3 dB reading (red LED on with
the Rane analyzer in the +3 dB mode), then the drivers
are properly phase aligned and no delay is necessary;
leave the MID DELAY control at minimum.
ii.If the display shows less than +3 dB reading (still in
green or in yellow on the Rane analyzer), slowing turn
up the MID DELAY control on the crossover until the
display shows +3 dB (red LED just on with the Rane
analyzer). Now the drivers are electronically phase
aligned and the Delay control should be left in this
position at all times unless the speaker system is
physically altered.
iii. If you have turned the MID DELAY control all the way
up and still do not have a +3 dB (red) reading, you will
have to physically move the high driver farther forward
Fig. 1 In-Phase Axis Response Without Time Delay
Fig. 2 Corrected In-Phase Axis Response With Electronic Time Delay on
Low Frequency Driver
Time Delay Adjustment Using
Realtime Analyzer & Pink Noise
This method outlines the use of a realtime analyzer, pink
noise generator and flat response microphone to set crossover
time delay. Some references will be made to the Rane RA 27
realtime analyzer for those with the intelligence and good
taste to use one regularly. The procedure applies to virtually
any analyzer system. We recommend using a 1/3 or 2/3
octave analyzer as either of these is more likely to match your
specific crossover points than a one-octave analyzer. And it is
important to match the analyzer to the crossover point as
closely as possible for proper phase alignment, otherwise the
analyzer readings may be misleading.
