During the recent AES Convention in New York, I attended a panel discussion entitled “Practical Advice for Wireless Microphone Users,” chaired by James Stoffo.
The panel included representatives of three top wireless microphone system manufacturers, including Joe Ciaudelli of Sennheiser, Karl Winkler of Lectrosonics, and Douglas Totel of Shure.
Stoffo has previously chaired panel discussions at AES that concentrated on large-scale wireless mic installations and applications such as the Super Bowl, but this year the focus was on the “typical” wireless user – a good move.
The discussion began with a look at determining operational requirements and expectations, such as how many channels might be needed, the form factor of transmitters, RF power, etc.
Some smart comments were offered by the panelists about providing a reality check to potential clients or customers about their expectations, with Ciaudelli making the point that “if it doesn’t need to be wireless, use a hard line” in addressing an example of a drummer requesting an in-ear system.
Focus then shifted to antenna types, including dipole and directional types, with Stoffo also noting helical antennas can help in avoiding the problem of antenna orientation, since performers tend to move around and hold transmitters in various positions.
The designs of Sennheiser and Professional Wireless Systems (PWS) helical antennas were compared, with a general conclusion that the Sennheiser unit is better suited for wider coverage applications while the PWS unit is better suited for longer range applications due to it’s narrower angle of coverage.
The need, or not, for RF amplifiers and/or amplified antennas was also covered, with the clear point made that boosters are needed only to overcome long cable runs rather than to “get a stronger signal”.
Coaxial cable loss was discussed in this context as well, with the recommendation to lean toward low-loss coax cables like RG213 and 9913F. It was also recommended to keep IEM transmitter antennas as far away as possible from rack receiver antennas to avoid overloading the receivers.
Of course, frequency coordination and band planning were on the docket as well, and specifically, preparation for multiple channels of wireless systems. Frequency coordination techniques mentioned include having pre-calculated backup frequencies at the ready. Totel showed an example of band planning where there was no overlap between IFB, IEM, beltpack and handheld groups.
Winkler also brought up the importance of proper audio gain staging to achieve optimum results, not only to keep the audio optimized but also because wireless mic transmitters need a healthy signal in order to modulate the RF carrier to get a good signal at the receiver.
Some of the tools available for wireless mic planning, including spectrum analyzers of various cost ranges, software tools, and resource web sites were covered.
The summary statements from each of the panelists centered on a common theme: planning is key to success, and having backup frequencies and other fallback plans help prevent problems.
I enjoyed the panel’s discussion, and the 60 or so in the audience appeared appreciative. In fact, many of them stayed afterward to ask further questions.
It looks like AES has found a good formula and excellent panelists for this topic, and I hope to see them continue with it in years to come.
