HK Audio CDR 210 F - Manual (Page 97)

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3 Overview of
Required Tools
Just three tools are needed:
• Allan (hexagonal socket) wrench, 3 mm to replace
the voice coil
• Allan (hexagonal socket) wrench, 4 mm to replace
the 8" speaker and rigging connector
• Screwdriver/power screwdriver
(see figure 4).
4 Replacing Loudspeakers
and Voice Coils
4.1 Subwoofer
All you have to do to replace the subwoofer is remove
the front grille. To this end, unfasten the Phillips
(cross-headed) screws on the front panel of the
grille and remove the grille. Then unfasten the hex
head bolts holding the subwoofer in place.
When installing a replacement speaker, connect
speaker wires to the proper posts, ensuring that
the polarity is correct! Red = +, black = -.
Note:
The two 10" subwoofers are wired in series!
4.2 8" Midrange Speaker
Proceed as follows to replace one of the two
8" speakers:
• Unfasten and remove the grille's four Phillips
(cross-headed) screws. Remove the grille.
• Unfasten and remove the four hex head bolts hol-
ding the 8" speaker in place.
• Now that the speaker is detachable, disconnect
the speaker wires.
When installing a replacement speaker, connect
speaker wires to the proper posts, ensuring that the
polarity is correct! The two 8" subwoofers are wired
in series.
4.3 The Driver's Voice Coil
Proceed as follows to replace the DE 900's voice
coil:
• Unfasten the mid/high enclosure's rear rigging
connector. To do this, loosen the four hex head
bolts in the rail.
• Unfasten and remove the eight Phillips (cross-
headed) screws holding the connector panel.
• Remove the connector panel along with the
attached crossover from the housing.
• Unfasten the voice coil housing's four hex head
bolts. Be sure to use an Allan (hexagonal socket)
wrench with a chamfered head because you will
unable to insert a straight wrench into the screw
head! Disconnect the wires from the push-pins.
• Take the lid off the voice coil housing.
• The voice coil can now be replaced.
Important:
Replace the voice coil in a clean working environment
only. Be sure to keep dust and dirt out of the open
driver. If despite your precautions particles manage
to get in, use a strip of adhesive tape to remove
them or carefully blow compressed air into the back
of the driver to whisk the particles out.
When installing the new voice coil, ensure it is
centered properly. Proceed as follows to check this:
Close the voice coil chassis' cover and reconnect
the cords (red = plus, black = minus). Feed a sine
wave signal between 1000 Hz and 1500 Hz into
the mid/high enclosure's input. Sweep through the
frequency. If you hear abrasive noises like crackling
or scratching, the voice coil is not centered properly.
Reopen the voice coil chassis and turn the voice
coil a bit until the signal is rendered cleanly!