Connection to the amplifier
Important! Please note: To avoid potential damage from short
circuits, all 3.5 mm jacks must be fully inserted into the Helix
X-just BEFORE powering up!
Disconnect the speaker cable from the amplifier to avoid
damage!
1.Connect the Blue „Signal in” cable to the X-Just by inserting its
3.5 mm plug into the X-just „Input signal” jack .
2.Connect the other end of the blue „Signal in” cable to one channel
of the amplifier’s speaker output terminals using the blue „Signal
in” cable’s alligator clips . It is not necessary to pay attention to
the correct polarity.
3.Connect the „Signal out” cable to the X-Just by inserting its
3.5 mm plug into the X-just „Output signal” jack .
4.Connect the other end of the „Signal out”cable RCA plug to
one channel of the amplifier’s RCA Input jacks. (Note:Use the same
amplifier input channel as used for step # 2 above).
5.Connect the red/black „Power 12V” cable to the X-just by
inserting its 3.5 mm plug into the X-just „Power 12V” jack.
Please note! This step has to be taken first before connecting
the alligator clips to the power as described in step # 6.
6.Connecttheother endof the„Power 12V”cable totheampli-
fiers 12V positive (red alligator clip) and ground (black alligator clip)
terminals.
Calibration
7.Set the amplifiers active crossover to its „full range”or „bypass”
position.
8.Set the amplifiers input gain controls to their minimum position.
9.Turn on the amplifier.
10. Move the „Off/Calibration/Measurement” switch on the X-
just to the „Calibration” position. The green „Calibration” LED will
illuminate.
11. Adjust the „Input Gain Calibration” control of the X-just to
its middle position.
12. Adjust the amplifiers gain control until the X-just blue „0 dB”
LED illuminates.
The calibration of the amplifier has been completed now.
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Important: The above procedure
(step 7-12)
calibrated the
system. Do not adjust the amplifier input gain or the X-just
„Input Gain Calibration” control further in order to achieve an
accurate measurement of the active crossover frequency!
Frequency adjustment
13. Select the crossover frequency range of the X-just by moving
the „12Hz-180Hz/0,1kHz-1,8kHz/1,2kHz-18kHz” switch to
the position for the desired crossover frequency.(ie: 90Hz would be
in the „12Hz-180Hz” range position)
14. Move the „Off/Calibration/Measurement” switch on the X-
just to the „Measurement” position. The Red „Measurement” LED
will illuminate.
15. Select the desired crossover frequency by adjusting the X-just
„Frequency” control until the desired frequency is displayed in
the X-just LED readout .
16. Switch the amplifiers active crossover on (can be either high-
pass or lowpass)
17.Adjust theamplifiers active crossover frequencycontrol until the
X-just blue „0 dB” LED illuminates.
The amplifiers active crossover frequency (-3dB downpoint) is now
adjusted to precisely the frequency shown in the X-just display .
18. Repeat the above procedure (step 2, 4 and 7-17) for other
amplifier’s channels as needed.
Please note: The amplifier must be turned off.
19. After adjusting all amplifier channels shut down the audio system.
20. Caution: To avoid potential damage power down the system
and disconnect the 12V and Ground alligator clips at the ampli-
fier before disconnecting the 3.5mm plug of the X-just!
21. After above adjustments are completed, the amplifiers can be
used as normal, their active crossovers will remain adjusted to the
desired frequency unless their frequency controls are moved. The
setted frequencies will also remain after adjusting the amplifiers
input gain control to the head unit.
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