Owner’s Manual
25
DD-8+ Power
HPF / LPF Output Filters And Delay
Output filters allow you to limit the bandwidth or range over which the amplifier and loudspeakers operate. This
is especially useful with small loudspeakers that have limited bass response. Limiting the range of frequencies
that the loudspeakers attempt to play may result in better sound quality and greater speaker reliability. Similarly
if high frequency response is undesirable in a given location it is easier to simply limit the high frequency output
here rather than with the PEQ. The Output Filters may also be used as crossovers when you want to use the DD-
8+ to bi/tri-amplify a passive loudspeaker or satellite/(passive) subwoofer system.
“HPF” is the High Pass Filter that passes through high frequencies and filters out low frequencies. “LPF” is the Low
Pass Filter that passes through low frequencies and filters out high frequencies.
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Figure 15. Effects of HPF @ 20Hz and LPF @ 15kHz, 12dB/oct.
1. Mode
Use the MODE dropdown to select between -6dB, -12dB, -18dB and -24dB per octave filter (roll off) slopes. The
default value is DISABLED. Steep filter slopes (-18dB, -24dB/octave) may introduce audible artifacts such as
“ringing” and may result in poor sound quality. It is best to start with the most gentle roll off filters (-6dB, -12dB/
octave) and assess the result before trying more severe roll off settings.
2. Freq(uency)
Type in the numerical value or use the slider icon or up/down arrows to select the frequency where the filter
starts to “kick in” (-3dB). Available frequencies range from 100Hz through 22kHz in 100Hz steps.
ADVANCED OPERATION
