Yamaha CM15V - Manual (Page 5)

5
ENGLISH
■ Subwoofers and the PN90 Crossover Network
Adding subwoofers to speaker systems like the one shown in the diagram can provide extended frequency range and
superior overall sound quality. After dividing the line-level audio from the preamplifier or mixing console into sepa-
rate frequency bands via the PN90 crossover network, the separate frequency bands are sent to separate power ampli-
fiers.
Precautions for operating the PN90
• Do not connect the PN90 between the power amplifier and speakers. The high voltage levels produced can damage
the PN90.
• Use the PN90 with a load impedance of between 7.5k Ω and 30k Ω . (Rated load impedance is 15k Ω )
• The polarity of the LOW signal is inverted at the crossover point between the LOW and HIGH signals. Compen-
sate for this by reversing the polarity when connecting the power amplifier output jacks to a subwoofer. Note that
you must reverse the polarity between the power amplifier and subwoofers rather than between the PN90 and
power amplifier to prevent damage to the connected device.
• The PN90’s connectors are unbalanced phone jacks. Use shielded audio cable with phone plugs to connect to the
PN90. Do not use speaker cable.
• Adjust the level of the LOW and HIGH signals using the power amplifier volume controls.
SUBWOOFER
MIXING
CONSOLE
TWO-CHANNEL
GRAPHIC
EQUALIZER
LEFT
INPUTS
RIGHT
PN90
LEFT
HIGH
RIGHT
INPUT
TO POWER
AMP INPUTS
LEFT
RIGHT
LOW INPUT
TWO-CHANNEL
POWER AMPLIFIER
TWO-CHANNEL
POWER AMPLIFIER
OUTPUT
OUTPUT
SPEAKER
SYSTEM
SPEAKER
SYSTEM
L
R
L
R
L
R
L
R
L
R
L
R
SUBWOOFER