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9.4 SETTING UP THE PROCESSING
Each preset menu allows access to all of the processing blocks that make up the
DSPXtra-AM Encore. There are further sub-menus inside each ‘preset’ menu.
The submenus follow the signal path through the DSPXtra-AM Encore, as shown in the
block diagram above.
'HIGH PASS FILTER'
This parameter allows you to select from a variety of high pass filters.
You can select from 20 Hz, 30 Hz, 40 Hz, 50 Hz and 60 Hz. You also have the ability to
bypass the high pass filter with the 'OFF option. The high pass filter can be used to
reduce rumble or can be effective in removing low frequency energy that most AM
receivers can't reproduce. We suggest you set the high pass filter to 30 Hz.
The
'EQ'
section contains the low frequency enhancement filters which are used to
provide bass enhancement and high frequency equalizer to provide high-end boost
(pre-emphasis).
‘PEAKING BASS EQUALIZER’
A pseudo parametric style bass equalizer control that allows
you to sweet tune the bass. Four frequencies, amplitudes and Q's are provided giving
you 6 different bass curves to select from. Frequencies selectable: 60 Hz, 76 Hz, 9 Hz and
120 Hz. Q's selectable: 0.4, 1, 2 and 4. Gains selectable: 0 dB, 1.5 dB, 3dB, 4.5 dB, 6dB.
'HF SHAPE'
Shifts the HF boost curve lower (values towards 1) or upper (values towards
10) in frequency. Lower numbers refer to lower frequencies and will boost more mid
frequencies as well as the high frequencies. Higher numbers refer to higher frequencies
and will put more emphasis on the higher frequencies than on the mid frequencies.
‘HF GAIN’
Adjusts the high frequency gain from 0 dB (no high-end boost) up to 0dB.
Some high-end boost might be beneficial to compensate for the typical receiver high-
end roll off. However, excessive high-end boost will be counteracted by the B AGC
levelling action.
The
'MULTI-BAND AGC'
is designed to re-equalize the program material and create a
consistent tonal balance while maintaining a consistent output level based on the RMS
level of the program material:
'B1-4' - each band has the following controls:
'DRIVE'
Controls the drive into the AGC. 0 dB drive corresponds to a gain reduction of
12dB, the midway point. The drive can be increased or decreased by up to 12dB. You
may need to increase the drive a little as you go up through the bands to compensate
for the fact that music has less energy in the higher frequency spectrum compared to
low frequencies.
'ATTACK'
Controls the attack rate of the AGC, The time the AGC takes to respond to an
increase of input level. The attack time can be varied between 1 and 10 which
corresponds to 100mS to 30S on a semi-exponential scale.
'DECAY'
Controls the release/decay rate of the AGC, the time the AGC takes to respond
to a decrease of input level. The DECAY time can be varied between 1 and 10 which
corresponds to 100mS to 30S on a semi-exponential scale.
