7
SBP8A INSTALLATION 
Setup and  Adjustment of Controls
Lowlevel(RCA)inputsignalispreferredforbest
performance. Typical trunk-mount installations
requirea17-20footRCAcable.Mosttrucksand
behind-seatapplicationsrequirea6-12footRCA
cable.UsingtwistedpairconstructionRCAcables
will minimize noise.
HighlevelinputsshouldonlybeusedwhenRCA
outputsarenotavailablefromtheheadunit.Connect
theheadunitspeakeroutputstothehighlevelinput
connector shown on page 6. Do not use both low and
highlevelinputsatthesametime-connectonlyone
or the other.
Theadjustablecrossoverisusedtofilterout
frequenciesabove70Hz~200Hz.Adjustittowhere
the SBP8A sound output blends with the rest of the
sound system.
The phase control compensates for delay between
the SBP8A output and the rest of the sound system.
Beginwiththephasecontrolsetto0degrees.If
thesoundisadequatefromthenormallistening
positioninsidethevehicle,nofurtheradjustmentis
necessary. If the sound is thin or lacking bass, adjust
the phase control until the bass is full and punchy.
Theinputlevelcontrol(gain)isusedtoobtainthe
best possible match between the head unit audio
output and the amplifier input. Begin by turning
theinputlevelcontrolfullycounterclockwise.Next,
turnuptheheadunitvolumecontrolaround3/4of
thewayup.Adjusttheinputlevelcontrolclockwise
until audible distortion is heard, then slightly
counterclockwisetoprovidethebestmatch.
The LED indicator illuminates blue during normal
operation.
Input Signal Connections
Low Level (RCA)
High Level Input  
(Speaker Wire)
Crossover Frequency 
Control
Phase Control
Input Level Control
LED Indicator