Stage Directions • April 2019 • Audio

There are a lot of wonderful resources available in our digital world today, instantly giving us access to legitimate experts on a range of topics. (Of course there is also no shortage in our digitally connected world to ‘self proclaimed experts’ but I digress). The point is there really are some solid, reliable resources, especially ones being curated on many of the leading manufacturers’ websites in our industry. Here at Stage Directions we often get people asking us for some direction to find an answer or information about a topic or help finding that true reliable expert. So, from time to time Stage Directions is going to start pointing out some of these true expert resources to all our readers.

One of those invaluable audio resources can be found on the Shure website. This site is filled with great information on their products but also on the state of the audio industry and there are lots of educational materials as well. These are resources that go beyond just how to use their product line but also looks at practices and audio issues in a broader way.

Of particular interest to the theatrical sound readers may be the continuing series of blog posts being written by Hayden Leiper. The series is called All About Wireless and is a true deep dive into the many considerations, concerns, and challenges of selecting, deploying, and operating a wireless system in today’s theater environments.

As Leiper notes in the start of the first installment: “As governments around the world sell off portions of the spectrum, it is becoming important for audio engineers to have a thorough understanding of wireless microphone and IEM technologies. For this reason, Shure have partnered with Entertainment Technology Asia to present a series covering RF Engineering theory and best practice. The intention is to provide readers with the knowledge required for the successful configuration and operation of their wireless systems. The series covers topics such as RF wave propagation; antenna types and positioning guidelines; signal distribution techniques; transmission line theory; sources of noise and noise mitigation techniques; mixing for IEM systems; analog vs. digital wireless systems; spectrum management and frequency coordination.”

Leiper’s credentials to share this advice is as an electroacoustic engineer with 15 years’ experience in the professional audio industry. Currently employed as a technical consultant with Shure Asia Limited, Leiper has worked previously as an applications engineer with Shure UK; a senior audio, video & communications engineer with Cirque du Soleil; a contract AV design & commissioning engineer & RF engineer.

The thirteenth edition discusses best practices regarding site evaluation and frequency coordination planning.

This post compares the ingress of noise in analog and digital wireless microphone systems.

The eleventh installment of All About Wireless discusses the bandwidth characteristics of analog and digital wireless microphone systems.

This issue examines the stereo multiplexing process and discuss techniques for maximizing the performance of IEM systems.

The ninth installment focuses on the generation and impact of intermodulation products.

This edition identifies several common sources of noise that affect wireless microphone and IEM systems.

This second part post is a continuation of the focus on transmission lines, examining the importance of impedance matching, the effect of standing waves, and the implications of transmitting RF over fiber optic cables.

This is a focus on transmission lines, beginning with an explanation of coaxial cable impedance and why 50-ohms is the standard in RF systems, followed by a review of cable loss specifications.

A post focusing on RF system connectivity; specifically, best practice recommendations for wireless microphone antenna signal distribution and combining, as well as IEM transmitter combining.

A look at antennas, covering the design and performance characteristics of those most commonly utilized in the professional audio industry.

This installment focuses on Electromagnetic wave propagation, covering the concepts of wavelength, reflection, diffraction, absorption and polarization.

This first post starts the series by looking at what Electromagnetic waves and the Electromagnetic spectrum actually are, and why we need to modulate signals for wireless transmission.

You can read this entire series at http://blog.shure.com/topics/ theater/ and while you are there we are sure you will discover lots of other useful information. The Shure website at shure.com is well worth a bookmark!