Danley DNA 10K4, Руководство пользователя

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Delay
The delay page controls the amount of delay associated with the output channel selected and is
adjustable from 0 to 998ms. The delay parameter is adjustable in fine steps at low values; the
adjustment becomes progressively coarser as the value increases.
High and Low pass Filters
High pass crossover filtering is provided for the output signal. Filter type is selectable from 1
st
order,
Butterworth, Bessel, Linkwitz-­‐Riley, Hardman and LIR Linear Phase. Filter slopes of up to 8th order or
48dB / octave are provided. Not all filter types are available in all slopes. For example 18dB / octave
Linkwitz-­‐Riley filters cannot be selected because they do not exist.
The Hardman type filter is always described by its order as the filter becomes progressively steeper
rather than following a linear slope so a dB/octave description is not accurate.
LIR Crossover Filtering
Unique to Danley Sound Labs, “Linear Impulse Response” (LIR) crossover filtering gives a Linear
Phase crossover which has a constant delay regardless of frequency (unlike other types of crossover
which delay different frequencies to a different extent, thus smearing the arrival time). The LIR
crossover can thus be described as having a flat Group Delay response, and thus entirely free of
Group Delay Distortion, this is exactly the same as can be provided by common FIR filtering but
without the complications and disadvantages inherent with the FIR technique.
The shape of the LIR crossover filter is similar to a 4
th
order Linkwitz-­‐Riley filter, and maintains zero
phase difference between the adjacent bands across the crossover region to keep the polar
response consistent.
Linear Phase filtering necessarily introduces delay; the laws of physics demand it. To keep this delay
to a minimum, it is recommended that more conventional crossover shapes (such as Linkwitz-­‐Riley)
are used for the very lowest frequency high-­‐pass edge, particularly if this is less than perhaps 100Hz,
which is well below the frequency thought to cause audible ‘Group Delay Distortion’.
This constant delay will depend on the lowest high-­‐pass frequency used in the crossover filters in a
given Drive Module.
Also see the section on Latency Delays .
Parametric Equalization and All-­‐Pass Filters
There are ten different EQ filters; two shelving filters and eight parametric filters. Parametric filters
are defined by frequency, bandwidth and gain. The frequency is controlled over the range from 10Hz
to 25.6kHz. The bandwidth, shown as Width on the screen, ranges from 0.10 octaves to 5.2 octaves.
Bandwidth can be shown and adjusted as Q or Octaves (Oct). Gain is adjustable in 0.2dB increments.
Any of the six Parametric filters can be used as All-­‐Pass filters. When a filter is set to All-­‐Pass mode,
the Gain parameter value will show as “AllPass” on the display. This setting may only be engaged or
disengaged from the PodWare PC application.
Also see Bandwidth Units in Utilities .