The DM84 combines a stackable 8-in/4- out automatic matrix mixer with a powerful DSP signal processing package and extensive remote control capabilities for any sound system application with multiple microphones and loudspeakers.
THE PROS
The Lectrosonics DM84 is part of the new equipment re-design of teaching spaces on campus at the University of Ottawa. The DM84 can be easily daisy-chained through its DANI (Digital Audio Network Interface) bus to provide a larger 24/24 configuration if required. Its DSP capabilities, ability to connect to unbalanced and balanced sources, and small form factor make it an ideal selection for a rackmounted solution. More importantly, the DM84 not only provides an optimized configuration through its intuitive internal software package, but also provides mechanical knobs at the front panel, which is critical when used by part-time personnel or students to manually adjust levels if required in certain conditions.
On campus, DM84 interfaces are stored in media control rooms and accessed via RS-232 protocol by an AMX control system (using a touchpanel located in the classroom and/or teaching space). All users have easy access to all audio controls and source material from the AMX touchpanel and the DM84 interfaces have provided a high-quality and rock-solid alternative to its analog predecessors.
THE CONS
The DM84 uses the DANI bus to connect one DM84 interface to another for expansion (a total of three can be connected in this way to provide a larger matrix). It would be practical if the company would provide better interconnectivity when using more than one DM84 interface. In large installations, when more than one DM84 is connected via the DANI bus, each module must be programmed separately. Ideally, it would be practical to load and configure all inputs and outputs at the master instead of connecting to each DM84 interface individually.
THE APPLICATION
Two DM84 interfaces are daisy-chained to provide a 16x8 matrix audio switcher in the larger classrooms and auditoria on campus. Configurations are standard, making for simple infrastructure troubleshooting yet flexible signal routing. With the emergence of digital processing in these newer systems, there is now an opportunity to include audio adjustments and control in the overall AMX integration. This overall integration provides for improved performance in the classroom while enhancing remote administration for the support staff.
THE RESULT
The University of Ottawa has an evergreening infrastructure replacement plan that supports existing and new multimedia installations on campus. Audio components (excluding microphones) have a 10-year life cycle in the university’s replacement plan process. In general, as analog mixers have become more and more costeffective, the build quality has suffered over the past few years. Symptoms such as defective sliders, high noise levels, power supply issues, and a reduced number of balanced inputs and outputs forced the university to look at alternatives.
With the decision to go with the DM84, there have systematically been a reduced number of calls for troubleshooting and repairs to the audio system. As well, there have been less client calls complaining about noise levels since the inputs and outputs are not always left in the “open” state (as is the case in the analog mixer scenario).
One important financial benefit in selecting the DM84 has been the removal of the AMX VOL3 interface. Since the DM84 dynamically attenuates inputs and outputs, the digital mixer can ramp up the volume, mute, and provide filters for each input and output to each classroom. This is not only a $400 savings per room, but improved flexibility (i.e., routing) and performance characteristics (less noise issues) as well.
With a dramatic increase in multimedia classrooms in the past few years and a limited number of technicians to support these rooms, procedures that simplify, improve, and provide remote administration of local sources from the head end make this and solutions similar to this one a logical choice.