Rane AC 22B (2003 version) User Manual
Page 12
Manual-0
Delay vs. Frequency Table
If you do not have the equipment necessary to electronically
align the system as described in the previous sections, you may
use the table below to obtain a rough and approximate phase
alignment of your drivers. Measure the horizontal displacement
between the voice coils of the two adjacent drivers sharing the
same crossover point, then find the column in the table nearest
your actual displacement. Move down this column to the proper
Crossover Frequency as indicated on the left of the table: the cor-
responding DELAY knob setting will then be the closest for your
system. For example, if you have a two-way system crossed over
at 800 Hz with the compression driver voice coil located about
9" behind the woofer voice coil, the Delay knob setting corre-
sponding to a 9" displacement at 800 Hz on the table would be
“5” as indicated on the front panel.
In order to phase-align two drivers you must observe only
the crossover frequency, which is common to both drivers. Pink
noise can be used if all other frequencies are disregarded, since
room acoustics and imperfect driver response will cause errone-
ous alignment attempts. Using pink noise as a source, each driver
is individually tuned to an arbitrary 0 dB level on the analyzer
display only at the crossover frequency. When both are turned on
simultaneously, the combined response of the two drivers should
read +3 dB higher at the crossover frequency on the display. If
the drivers are not phase-aligned, some cancellation will occur
on-axis, resulting in a combined response less than +3 dB. Turn-
ing up the DELAY control causes the lower driver to electroni-
cally move backward until the analyzer reads +3 dB; then the
two drivers are electronically aligned and the on-axis cancella-
tion is eliminated (see Figure 2 on page Manual-6).
Voice Coil Displacement (Inches)
(Hz)
.75" 1.5" 3"
6"
9"
12"
15"
18"
21"
24"
70
1
1.5
2
2.5
3.5
5
6
7
8
MAX
80
1
1.5
2
2.5
3.5
5
6
7
8
MAX
100
1
1.5
2
2.5
3.5
5
6
7
8
MAX
150
1
1.5
2
2.5
3.5
5
6
7
MAX
200
1
1.5
2
2.5
3.5
5
6
7
MAX
250
1
1.5
2
2.5
3.5
5
7
8
MAX
300
1
1.5
2
2.5
3.5
5.5
7
MAX
400
1
1.5
2
2.5
4
6
8
MAX
450
1
1.5
2
2.5
4
6
8
MAX
500
1
1.5
2
2.5
4
6
8
MAX
800
1
1.5
2
3
5
7
MAX
lk
1
1.5
2.2
3
6
MAX
1.2k
1
1.5
2.2
3.5
MAX
1.5k
1
1.5
2.3
3.5
MAX
2k
1
1.5
2.3
MAX
2.5k
1
1.5
2.3
MAX
3k
1
1.7
2.4
MAX
3.6k
1
1.7
MAX
4k
1
1.8
MAX
6k
1
2
MAX
7k
1.2
MAX
Crosso
ver Fre
quency
Fig. . Vertical Driver Displacement
Displacement