Rane AC 23 Operator'S Manual Download Page 14

Manual-14

 Delay vs. Frequency Table

If you do not have the equipment necessary to electroni-

cally align the system as described in 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 corresponding 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 disre-
garded, since room acoustics and imperfect driver response
will cause erroneous 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. Turning up the
DELAY control causes the lower driver to electronically
move backward until the analyzer reads +3 dB; then the two
drivers are electronically aligned and the on-axis cancellation
is eliminated.

Crossover Frequency

                   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

Displacement

Fig. 3 Vertical Driver Displacement

Summary of Contents for AC 23

Page 1: ...e some dead channels in the unit when looking for output in places where there shouldn t be any The even more automatically confusing part is the way that the Output connectors decide whether the unit...

Page 2: ...tting the Output Level Controls on page Manual 15 LOW MUTE switch When pressed to the in position all signal is removed from the Low Frequency Output This eases tune up procedures as described on page...

Page 3: ...1 Input CHANNEL 2 will drive BOTH Channels of the AC 23 internally HIGH FREQUENCY OUTPUTS These are TS tip sleeve unbalanced Output jacks Connect the CHANNEL 1 HIGH OUT to the left channel input of th...

Page 4: ...to 2 ms of time delay to the Low Frequency Output only This allows a low frequency driver to be electronically phase aligned with a mid frequency driver whose diaphragm is situated behind the low fre...

Page 5: ...ANNEL 2 will drive BOTH Channels of the AC 23 internally HIGH FREQUENCY OUTPUTS These are TS tip sleeve unbalanced Output jacks Connect the CHANNEL 1 HIGH OUT to the left channel input of the high fre...

Page 6: ...the Subwoofer and Low Outputs Refer to page Manual 10 to determine the proper setting for your system LOW LEVEL control Sets the Level going to the Low frequency Output LOW MUTE switch Removes all sig...

Page 7: ...PLUG INTO THIS OUTPUT FOR 4 WAY MONO OPERATION IMPORTANT NOTE CHASSIS GROUNDING If after hooking up your system it exhibits excessive hum or buzzing there is an incompatibility in the grounding config...

Page 8: ...Use this output only for Mono 5 Way applications Omit this output when using the AC 23 as a Mono 4 Way Crossover As long as no plug is inserted into this jack the AC 23 internally bypasses the Hi Mid...

Page 9: ...hannel 2 input Note For this alternate Mono 4 Way installation connect a patch cord from the CHANNEL 1 HIGH OUT to the CHANNEL 2 INPUT as shown See warnings above SUBWOOFER OUTPUT These are TS tip sle...

Page 10: ...nd a moment here to re affirm why this delay is really necessary For a short course on time delay Linkwitz Riley and other mouth watering details we recommmend the Linkwitz Riley Crossovers RaneNote A...

Page 11: ...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...

Page 12: ...PL Meter Tone Generator Now that good quality realtime analyzers are becoming more affordable and easier to use there are few reasons why one of these should not be regularly used in any sound system...

Page 13: ...er is actually in front of the mid driver adding delay to the mid driver then only worsens the situation There are a couple of ways to deal with this a Try to move the high driver back as far as possi...

Page 14: ...river response will cause erroneous 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...

Page 15: ...nded methods of setting the crossover output Levels Setting Levels Using a Realtime Analyzer NOTE If you are running two Channels tune up only one Channel at a time 1 Set all LEVEL controls on the cro...

Page 16: ...ng any settings on the SPL meter adjust the cross over MID LEVEL control until you obtain a 0 dB reading on the SPL meter Now the low and mid speakers are set at the same level 7 Now press the MID MUT...

Page 17: ...ind the Channel 1 LF LEVEL pot find the jumper labeled W22 3 To remove the Delay 3 circuit from the Low Frequency output remove both the W28 and W22 jumpers 4 To get the Low Frequency output to work a...

Page 18: ...vity Horn Equalization Modification Constant Directivity or CD horns need additional equalization to help cover the same area a long throw horn can cover Additional circuitry has been added to the AC...

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