LAS VEGAS - Prior to the exhibit hall for InfoComm 2018 opening on Wednesday, I spent much of Tuesday taking in a couple of educational seminars, along with spending time in the various audio demo rooms throughout the North Hall at the Las Vegas Convention Center.
Among the most notable workshops was a seminar, Loudspeaker and Amplifier Specifications, focused on what settings and specs, and how they can be seen as solid indicators toward achieving the desirable audio system for your space. The presenter, Pat Brown, looked at calculations and specifications such as how different in value a root means square, or RMS, measurement for power capabilities for amplifiers, for example, is a much more reliable number to go by, versus watts peak, which he said, “is not a good thing, as it overstates the power capabilities of the equipment.” Beyond just the watts RMS, Brown also looked closely at the impedance and voltage as two other areas that are crucial in matching the right amplification to the right speaker, and avoid any potential damage to gear down the road.
In addition, the way that power ratings can be measured can include from what Brown described as a “burst rating,” which are calculations based on a 10- to 15-second time window, to how some data can be skewed. As sound system designers, one needs to know what is behind such ratings. One example to how numbers can be egregiously skewed, he discussed how a car amplifier manufacturer, in one case claimed 2,000 watts for a specific piece of gear. But when it was run through the paces during testing, that same piece of equipment showed only around 400 watts RMS in rated power. As he added, “You need data that is relevant for a purpose.”
When looking at the specifications relating to loudspeakers that could be selected for your worship space, a key factor and specification he highlighted was sound pressure level, or SPL. The typical way a loudspeaker is measured, he added, applies 2.83 volts, which translates into 1 watt (for 8 ohm speakers), into a calculation of decibels. The higher the number (often in 90dB or higher), amounts to a higher sensitivity for a speaker, which translates to how one requires less power to drive such speakers, while leaving headroom for a speaker’s reference level peaks.
During another Tuesday session, Designing Efficient Cost-Effective Distributed Audio and Integrated Hardware Control, hosted by Allen & Heath Product Manager of Installation, Martijn Verkerk, he spent some time reviewing the vast array of protocols on the market that work in hand with the Allen & Heath line of products.
Whether a system can work within various networks, ranging from a Local Area Network (LAN), a Wide Area Network (WAN) or a Wireless Area Network (WLAN), there are a series of expectations with regard to the sound demanded from such a configuration. They typically will include low latency, an easy setup, a system that offers high flexibility, requiring low maintenance, and one that incorporates a 100 percent duty cycle.
Among the various protocols on the market that the Allen & Heath line, including the SQ Series (SQ-5, SQ-6, and SQ-7) discussed in detail were the Dante protocol by Audinate, Waves Soundgrid, gigaACE, DX Link and SLink, among others. In describing each protocol, he outlined how a protocol such as DX Link offers low latency, and automatic firmware matching, while Dante can coexist with different network traffic, while being able to with up to 512 bidirectional audio channels at 48 kHz, among other benefits.
Having hardware with such flexibility is key, allowing to make changes to which protocol is most ideal for your system setup, without being locked into a specific protocol for the long-term.