Sepura Plc, a designer and manufacturer of digital mobile radio products for public safety, industrial, commercial and military applications, recently implemented a Harman Soundcraft Si Expression 1 digital console at its Cambridge, UK faclities to improve and streamline processes during product testing stages.
The Si Expression 1 is situated next to an acoustic testing chamber with a head and torso simulator, to test against specifications in typical usage scenarios, including background noise testing using surround sound. This system is set up to accommodate a binary goal: the automatic verification of products during late development stages and the manual acoustic testing during early development stages of software, terminals and accessories.
“These two activities have conflicting requirements and this is why we purchased the Si Expression,” says Edmund Elsey, senior acoustic engineer at Sepura Plc. “Our automated tests are run with in-house software that control our terminals remotely, which requires the signals to be routed to and from different equipment, depending on the test. We used a switching unit to route the signals, which not only introduced noise and ground loops, but also prevented easy monitoring. For manual testing, we needed to partially dismantle and reconfigure the system, as well as adjust signal levels and EQ.”
“However, the Si Expression allows for automated routing, monitoring of any input, and GEQ functions all in one,” he continues. “I now have all the equipment permanently connected because I can control routing from any input to any output using MIDI control messages sent directly from our software. For manual measurements, I can route any signal anywhere I like.”
The Soundcraft Si Expression is a flexible digital console that provides a value at its price range, with intuitive features such asFaderGlow, which illuminates the faders with color coded LED lighting. Workflow is taken to new heights, as monitoring, functions and effects are designed to be efficient and hassle-free. For example, Elsey found that he could use the GEQ to implement correction functions at any time through the bypass feature and customize the fader layout.
“I worked with a Soundcraft analog console before, and tried a demo of the Si Expression at Harman’s UK distributor Sound Technology, so I know that Soundcraft lives up to its name by manufacturing high-quality mixing desks,” he explains. “We also made sure that our high-powered digital radios would not interfere with the desk, as to not introduce TDMA noise onto the signals. In fact, I was impressed that Soundcraft sent me a copy of their EMC report when I enquired about RF immunity.”
“The Si Expression massively improved productivity in our test environment, because now the whole system can be configured at the touch of a button for different use cases,” Elsey concludes. “The THD and noise floor are also great and have been verified to be more than adequate for our needs.”
