At Gentex, the software was configured to the needs of the project, just as described above. In addition, we used many of the P4800’s external control features, including the DRS10 scene controller that allows easy selection between presets. (Up to 128 presets can be configured and stored.)

Another handy feature: the unit is compatible with both AMX and Crestron control systems, and more relevant to the Gentex project, it also supports simple controls such as potentiometers and switches. We chose to interface 10k pots for discrete volume control of loudspeaker zones and a single pole “bat handle” switch for muting (all installed at the rack with the P4800 and system power amplifiers).

Setting up the control pin configuration within the software was a piece of cake. I simply went to the “devices” menu and opened the control pin configuration option. Once there, a window popped up that allowed selection of the control device (momentary, switch, pot or custom). From there, simply select the device and assign it. This worked well, and with no trouble shooting required. As I had experienced during my initial evaluation, system setup and configuration was simple.

On wireless microphone inputs for the Gentex system, I found that the P4800’s DFR auto EQ/feedback elimination block worked very well. These input channels were also fine-tuned through use of the P4800’s parametric EQ, with high- and low-cut filters.

Tailoring EQ for the wireless systems.

And, on this system’s “paging feed” input channel, I added two more P4800-unique features: an AGC-leveler (automatic gain control) and a Downward Expander. Both are quite useful in enhancing vocal clarity and intelligibility.

The AGC-leveler helps maintain a constant volume level even if the talker is moving back and forth in relation to the mic. Meanwhile, the Downward Expander attenuates the level of a signal below its threshold, reducing background noise (air conditioners, fans, etc.). The expander is similar to a gate, but instead of completely muting signal levels below the threshold, it simply lowers them to a less noticeable level when there is a pause in program material.

Meanwhile, on the output side, I added another EQ for room equalization, as well as a limiter (set as a brick wall) and a delay device for each output so that point of source origin can be optimized at several locations in the room. (A stage can be located at four different locations in the room, requiring the zoned loudspeaker system to reconfigure delay relative to stage position.) These different delay settings, established within the presets, are easily selectable on the P4800 software or using the DRS10 rotary switch by even the most non-technical of users.

One neat facet of this project is that the facility’s management did not understand or even ask about what we did or how we did it - they were simply thrilled with the final outcome and the way the system is so easy to configure for different needs, and without need of a mixing console or experienced operator.

In summation, the Shure P4800 is a very good entry in the configurable DSP arena for installed sound systems. For small-to-medium sized applications like the one described above, it offers a decent amount of total processing power, and for larger systems, as mentioned, numerous units can be networked for control. This, in addition to its stability, flexibility and extreme ease of configuration, make it a useful contracting tool well worthy of consideration.

(Gary Zandstra designs and supervises A/V systems for Group Signal of Holland, MI, and can be reached at garyz@groupsignal.com.)