With speech intelligibility an essential consideration, the Arizona State Legislature found itself in trouble with poor audio, feedback, inconsistent mic levels and a variety of other issues. At the heart of its solution were Aspen digital audio processors from Lectrosonics, aslong with a selection of Shure mics and a Tannoy loudspeaker system.
As a design/build firm specialising in A/V projects for government, medical, houses of worship, and institutional clients, Intent Digital stepped in to make the upgrade.
Lectrosonics Aspen SPNConference interface and power amplification units used in conjunction with Aspen SPN2412 24-input/12-output audio processors.
The installation began in January 2013, while the Legislature was in session, so much of the work was performed when meetings were not scheduled. The first set of mixers were activated in early February and the rest were brought on line progressively. The last set went live at the end of March.
‘The two Aspen systems – one each for the Senate and House of Representatives – are interfaced with our firm’s Energize Control System,’ says Bob Ginger, Technology Partner with Intent Digital.
In the Senate, the Intent Digital team deployed a single Lectrosonics Aspen SPNConference unit that is interfaced with three Aspen SPN2412 processors. This system is configured as a 72 x 36 matrix. For the House of Representatives, another SPNConference unit is interfaced with five more Aspen SPN2412 processors. This system is configured as a 120 by 60 matrix.
Completing the system in the Senate are 52 Shure gooseneck microphones, 50 Tannoy CMS501 loudspeakers, a JBL CBT50LA Constant beamwidth loudspeaker, two eight-channel Crown CT875 amplifiers, and a Crown XFMR4 transformer panel. In the House of Representatives, there are 112 Shure gooseneck microphones, 55 Tannoy CMS501 loudspeakers, 12 Tannoy Di5 loudspeakers, four CT875 amplifiers and XFMR4 transformer panel.
‘In both legislative bodies, these systems handle all audio for the various public committee hearings and voting sessions,’ Ginger says. ‘The Senate has four hearing rooms while the House has five. Both Aspen systems are controlled as one system via the Intent Digital Energize touchpanel, which is located at the Arizona Capitol Television Master Control. There are also Energize single-gang touchpanels in the Senate hearing rooms for basic room audio control. The Aspen system handles mixing of wired and wireless microphones in all rooms, as well as telephone conferencing, mix minus, press feeds, assisted listening feeds, recording and broadcast feeds, and room combining functions.’
‘The Aspen system is tailor made for this type of application,‘as its architecture is optimised for matrix mixing, equalisation, feedback elimination and auto-gain, without having to program a DSP project,’ Ginger says. ‘Having 48 mix buses available to create a multitude of program and mix minus feeds that can be sent to any combination of outputs at differing operating levels is a very powerful aspect of the Aspen processors. The Energize control system operates seamlessly with the processors to create any project configuration. The Aspen system can store the base default operating settings and Energize keeps track of the dynamically changing parameters. Therefore, if the system has to be restarted, Energize will set all the Aspen levels to the last good setting.
‘With the Lectrosonics equipment, it’s easy for our engineering team to create mixer configuration notes that engineering techs can use to quickly configure the Aspen units,’ he adds. ‘We don’t have to go through the DSP programming effort to create a project. Energize easily communicates with the Aspen systems over either a serial connection (RS-232) or Ethernet. We created live mixer touchpanel control pages for each room, some of which have as many as 32 microphones. The pages also contain output controls for room speakers, broadcast, recording, and assisted listening feeds. We are using quite a bit of mix-minus capability for speakers over the meeting participants heads, which is working very nicely for consistent sounding audio throughout the various rooms. The Energize control system does not require any software coding or compiling. Instead, it contains an impressive set of point-and-click tools to quickly select how source, output, mix bus, or crosspoint gains or mutes are to be controlled. This makes it very easy to gang any combination of audio mixes to an Energize control object. The audio sounds fantastic, rich and full, without feedback.’
