Processing Parameters
27
compensate for the effects of pre-emphasis when the DSPXtra-FM has pre-emphasis enabled (FM appli-
cations). The shelf control can also be used to tame high frequency energy when the box is configured
for DR applications and no pre-emphasis is enabled.
'B1-2 ATTACK'
Controls the average attack rate of the B1-2 look-ahead limiter. This defines the energy
distributed into the secondary time constant circuit. The attack time can be varied between 1 and 10
which corresponds to 10mS to 2000mS on a semi-exponential scale.
'B1-2 DECAY'
Controls the average decay rate of the B1-2 look-ahead limiter. This defines the decay
rate of the secondary time constant circuit. The decay time can be varied between 1 and 10 which corre-
sponds to 10mS to 2000mS on a semi-exponential scale.
'B3 ATTACK'
Controls the average attack rate of the B3 look-ahead limiter. This defines the energy dis-
tributed into the secondary time constant circuit. The attack time can be varied between 1 and 10 which
corresponds to 10mS to 2000mS on a semi-exponential scale.
'B3 DECAY'
Controls the average decay rate of the B3 look-ahead limiter. This defines the decay rate of
the secondary time constant circuit. The decay time can be varied between 1 and 10 which corresponds
to 10mS to 2000mS on a semi-exponential scale.
'B4 ATTACK'
Controls the average attack rate of the B4 look-ahead limiter. This defines the energy dis-
tributed into the secondary time constant circuit. The attack time can be varied between 1 and 10 which
corresponds to 10mS to 2000mS on a semi-exponential scale.
'B4 DECAY'
Controls the average decay rate of the B4 look-ahead limiter. This defines the decay rate of
the secondary time constant circuit. The decay time can be varied between 1 and 10 which corresponds
to 10mS to 2000mS on a semi-exponential scale.
The
'CLIPPER'
menu contains the clipping controls that form the final peak limiting stages of the DSPXtra-
FM’s FM mode of operation.
'MULTI-BAND CLIP DRIVE'
Controls the drive into the multi-band clippers that precede the main clipper.
Adjustable over a -6dB to +6dB range.
'BASS CLIP LEVEL'
Controls the clip level of the mix of Bands 1 and 2
.
The clip level range is -6dB to
0dB referenced to the main clippers output level.
'BASS CLIP TYPE'
Controls the action of the bass clipper. Hard provides maximum punch by using
the filtered harmonics of the clipped bass signal to create the illusion of more bass. Soft employs look-
ahead techniques to dynamically control the bass clip level. This creates a more natural soft clip action
which may be preferred for some formats. The soft clip option can raise the bass to 100% modulation as
opposed to the hard option which does not allow bass to exceed the bass clip threshold. The soft option
will add almost 5mS extra delay to the audio path.
'BASS CLIP SHAPE'
Controls the shape of the bass clip transition. Fat is square topped traditional hard
clipping and med and slim smooth out the clipping transition slightly and help reduce distortion a little.
'MID CLIP LEVEL'
Controls the clip level of band 3
.
The clip level range is -12dB to 0dB referenced to
the main clippers output level.
'HF CLIP LEVEL'
Controls the clip level of band 4
.
The clip level range is -12dB to 0dB referenced to the
main clippers output level.
'HF CLIPPLING'
This control redistributes high frequency peak control between the six band limiters and
the HF clipper
.
The range is 0 to 17 with 0 equating to full control by the limiters and higher numbers pro-
ducing less control by the limiters on a frequency dependent basis, leaving control by the HF clipper. This
control is similar to a variable de-emphasis control in the limiters side-chain control signals.
'MAIN CLIP DRIVE'
Controls the drive into the main output clipper that defines the systems peak clipping
ceiling. Adjustable over a -6dB to +6dB range.
'COMPOSITE CLIP
Controls the drive into the composite clipper which effectively sets the amount of
composite clipping. The range of composite clipping is -0.5dB to +2dB.
The
'ADVANCE'
menu contains the controls that fine tune final clipping
Summary of Contents for DSPXtra-FM
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