Klipsch KA-1000 THX Manuel Du Propriétaire page 5

4. AC Line Cord
The AC Line connection uses a detachable three-prong power cord. Insert the line cord
into this jack, set the Master Power switch to "Off", then insert the power cord into an
appropriate AC receptacle. Leave the Master Power switch off until all connections are
completed. (We recommend leaving the Master Power and Auto Power switches in the
"On" position for normal operation in most systems.)
CONNECTION AND ADJUSTMENT
The KA-1000 THX is a high-performance, THX Ultra2-certified Class D digital power
amplifier with a built-in subwoofer crossover. It is designed specifically to drive one or
two KW-120-THX subwoofers to maximum output without audible distortion or risk of
damage. Although the amplifier's connections and controls are simple, their use varies
somewhat according to the subwoofer system's application. Typical setup procedures are
described in the following sections – one for digital systems and one for analog systems.
THX / Digital Surround Receiver or Processor Connection—Today's Dolby Digital
and DTS digital surround receivers and processors, as well as all THX-certified
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models, have line-level subwoofer outputs and built-in subwoofer crossovers. If your
system is built around one of these, it will almost always be best to use the KA-1000
THX with the THX switch in the "On" position. This will bypass the crossover and level
controls. Connect the subwoofer output on the receiver or processor to one or both of
the KA-1000 THX's two input jacks (Figure 2). Use a shielded, high quality subwoofer
interconnect cable of appropriate length with RCA plugs on each end. Your dealer can
help you select a suitable cable. Be sure to go into your receiver or processor's speaker
setup menu and set Subwoofer to "On" or "Yes", or if it is a THX Ultra2 certified model,
select "Ultra2" in the subwoofer menu. Your receiver or processor may have additional
bass management abilities beyond simply activating the subwoofer output. Consult
your receiver or processor's owner's manual or your dealer for more information on the
proper bass management settings for your system.
Crossover Adjustment – With the THX switch in the "On" position as suggested for
this type of setup, the crossover control will not function. Its status LED will be red
signifying that this control is bypassed. Your receiver or processor will perform the
crossover functions for the subwoofer in this situation. When using either the KL-650-
THX or KL-525-THX as your front speakers, select the 80Hz (THX) crossover frequency.
Level Control – With the THX switch in the "On" position as suggested for this type of
setup, the level control will not function. Its status LED will be red signifying that this
control is bypassed. Your receiver or processor will perform the volume level functions
for the subwoofer in this situation.
Phase Control – In some installations the setting of the Phase control may not make
much difference, whereas in others it may be necessary to go back and forth between
the Phase and Level controls for a while in order to get the very best blend with the
main speakers. Since each control setting (including the one for crossover frequency in
the receiver or processor) affects the optimum settings for the others, it often takes a
while to get everything dialed in just right. Start with the Phase control at 0° and play
a recording with a prominent, repeating bass line in your listening position. Repeat
this process with the control in the 90° and 180° positions. Use the setting that yields
the greatest bass output.
Non-THX / Analog Surround Receiver / Processor or Two-Channel Stereo System
Connection – Some analog A/V receivers and processors (without Dolby Digital
DTS capability) have a line-level subwoofer output. Others have left- and right-
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channel line-level outputs, as do some stereo receivers and integrated amplifiers.
All separate stereo preamps and surround processors have line-level outputs. If your
system is built around one of these, it will almost always be best to use the KA-1000
THX with the THX switch in the "Off" position. This will activate the crossover and level
controls. These types of outputs should be connected to the KA-1000 THX's line-level
inputs (Figure 3). You will need one or two shielded, high quality interconnect cables
of appropriate length with RCA plugs on each end. Your dealer can help you select
suitable cables.
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• Subwoofer Output – Connect the subwoofer output jack to one of the line-level
input jacks on the KA-1000 THX.
• Preamp Outputs on Receiver or Integrated Amplifier – If your receiver or
integrated amplifier has spare preamplifier outputs for its front left and right
channels, connect these to the line-level inputs on the KA-1000 THX.
• Pre-out/Main-in Loops on Receiver or Integrated Amplifier – Some receivers and
integrated amplifiers have their preamplifier and power amplifier stages connected
externally via jumpers. If yours has its left and right front channels connected this
way, you can connect the KA-1000 THX to those preamp outputs. You will need a pair
of Y-adaptors, each with two male RCA plugs and one female RCA jack. Remove the
jumpers for the two channels. For each, plug one leg of a Y-adaptor into the preamp
output jack and another into the main amp input jack. Plug the cables leading to the
KA-1000 THX into the female ends of the Y-adaptors.
• Separate Preamplifier or Surround Processor – You will need a pair of
Y-adaptors, each with one male RCA plug and two female RCA jacks. Unplug the
cables leading from the front left- and right-channel outputs on the preamp or
processor and plug the Y-adaptors into them. For each channel, plug the cable
leading to the power amplifier into one of the RCA jacks on the Y-adaptor and the
cable leading to the KA-1000 THX into the other.
Crossover Adjustment – With the THX switch in the "Off" position as suggested for
this type of setup, the crossover control will be activated. Its status LED will be green
signifying that this control is active. Set the control to the approximate low-frequency
limit of your main left and right front speakers. If you don't have their specifications,
take an educated guess based on the size of the speakers. A large speaker will usually
work down to lower frequencies than a small speaker. So for a large floorstanding
loudspeaker, you might start with the Crossover frequency set all the way down to
40Hz, whereas for very small satellite speakers you might want to turn it all the way
up to 120Hz. Typical bookshelf speakers would tend to be in the 50Hz to 80Hz range. If
the crossover frequency is set higher than 100Hz, the subwoofer should be in the front
of the room near the front main speakers.
Level Control – With the THX switch in the "Off" position as suggested for this type of
setup, the level control will be activated. Its status LED will be green signifying that
this control is active. Play a variety of music recordings containing strong but not
overpowering bass. Adjust the KA-1000 THX's level control until the music sounds
consistently warm and natural. If you have trouble getting enough low bass without
the sound becoming boomy, it probably means the Crossover control is set too high. Try
turning it down a bit at a time until the problem goes away. If the sound is thin until
you turn the subwoofer Level up so much that lower bass is too prominent, start by
varying the setting of the Phase or Boundary Gain Compensation controls. If that does
or
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