USL JSD-60 Manual - Manual (Page 10)

Page 10
A user configurable mixer routes audio as required for the specific auditorium. Supported auditorium
configurations include 5.1, 7.1DS, 7.1SDDS, and drive-in.
5.2
Block Diagrams
The following simplified block diagrams assist the user in understanding the signal flow within the JSD-60. All input
sources are routed to the Input Mixer that routes a source to an output. An internal noise and tone generator is
available for testing and acoustic calibration of the sound system. The output stream contains the main fader, sync
and surrounds delays, equalizer, channel filter, and crossover with individual band delays and gain settings. The
hearing impaired (HI) and visually impaired - narrative (VI-N) outputs do not include an equalizer, channel filter or
crossover and are not affected by the main fader.
Figure 5.2a Audio Processing Overview
The output of the mixer or internal generator is routed to the main fader control. The output is then routed to a
delay for both projector synchronization and surrounds. The crossover includes individual delays for high and low
bands. Each channel, with the exception of LFE, HI, and VI-N, has a 27 band graphic equalizer including bass and
treble shelving filters. After equalization a channel filter process can be applied. The channel filter can be used to
apply special effects to a specific channel. For example, it may be desirable to notch out dialog frequencies on a
generated Lc or Rc channel. The channel filter supports high pass, low pass, band pass, notch, and disabled. The
LFE channel is routed through a parametric equalizer and a 125Hz low pass filter as specified by SMPTE EG0432-2-
2006. When the internal crossover is not used, full-range audio is sent to the low-band outputs. The outputs are
driven with balanced line drivers through solid state switches used for muting. Similar switches route bypass audio
to the left and right outputs when required.
As shown in Figure 5.2b, each input is digitally converted (analog to digital or sample rate conversion) and routed
to the mixer within the DSP. The two channel sources are converted and then routed to a Sample Rate Converter
(SRC) that can be either mixed or have an active matrix applied to them to generate six digital audio sources (5.1