Designing audio systems for ships at sea magnifies many of the challenges of similar systems designed on land. For instance, as outlined in Edwards' paper, ambient background noise on ships can reach 55 dBA or higher from engine vibrations and HVAC turbulence, placing a premium on properly distributing systems. In addition, ships tend to contain materials - glass, tile, and metal - that are notoriously problematic from an acoustical standpoint. Ships at sea also present logistical challenges not shared by their land-based counterparts. System usability and reliability become paramount, as it is not possible to simply drive over and show someone how to use something or replace a malfunctioning component. To address all of these issues, SymNet DSP units are now Edwards' go-to solution.

For the Luminosa and Deliziosa, Edwards used the organizing principle of a broadcast DSP to simplify what are otherwise fairly complicated networks, relying on CobraNet to deliver common signal throughout the ship over cost-effective CAT5 cable. A SymNet Express CobraNet 12x4 DSP wrangles a number of input sources (local mp3, CD, etc. as well as satellite radio) for distribution throughout the ship.

Each venue shares a relatively uniform user control structure. SymNet ARC-SWK controllers, often redundantly located at several convenient locations, provide source selection and volume control. The ARC-SWK features four push buttons and a rotary knob that can control two continuous parameters (one with the knob pushed in and a second with the knob in its default position). Typically, three of the push buttons select input sources delivered from the broadcast DSP, whereas the fourth push-button is local. In its default position, the knob controls output volume. When pushed in, for instance, it controls the input volume of a local microphone.

"It seems to me that a lot of other DSP manufacturers focus all of their attention on the processing itself and leave the interface as an afterthought," said Edwards. "It's obvious that not only has Symetrix put their all into the processing, they've kept the interface options at the forefront while doing so. The ARC controllers work on the network and are flexible enough to be programmed in any way that makes sense for the end-user. Things can be redundant or not. The programmable colors of the LEDs adjacent to each push button open up a world of possibilities for intuitive user control. I am able to succeed in designing systems that anyone, not just an A/V tech, can control."

Depending on the situation, Edwards employs SymNet's other ARC interfaces to effect specific solutions. For example, a show relay system provides easy communication between front-of-house and backstage. "That way, the stage manager can communicate with the backstage actors and technicians," said Edwards. "The ARC interfaces allow for XLR mic input along with push-button control for temporary, latch, or permanent communication. In addition, audio signal gets carried on the same CAT5 that connects the interface to the hardware processor, which greatly simplifies the installation."

The addition of FIR filters to SymNet's long list of processing modules has further simplified and elevated Edwards' sea-worthy designs. "I recently did a string of retrofits for Holland-America ships," he said. "They were redesigning the main showroom, and adding two Electro-Voice XLVC line to a newly-installed :ED video wall on the back deck. With the new SymNet FIR module, I was able to perfectly match the loudspeaker conditioning to Electro-Voice's XLVC specifications. It brought the whole venue to life!"