RF based measurement

Why measure wirelessly? There are (2) really good reasons I can think of.

1. time savings
2. microphone health

Using long mic cables, I’ve already seen my expensive measurement mic fall on the floor multiple times 🙁
I rarely have more than 15 to 30 minutes to “attempt” to tune a system which may & often times includes (stereo mains, subs, front fills, under balc delays, over balc delays, center cluster, etc…) Once you understand how even a slight delay offset can ruin the frequency & phase response of a sound system, it becomes obvious that one MUST measure and correct whenever possible.

There are currently only (2) options on the market for taking FFT measurements wirelessly. The most off the shelve ready option is the Lectrosonics TM400 kit.
Lectrosonics TM400
tm400

The other option is offered by Line 6.
Line 6 XD-V75
With the Line 6 XD-V75 beltpack transmitter / receiver combination & an appropriate omni capsule wired with the right connector, you have a world class wireless measurement rig. Examples of an appropriate omni mic element would be a Sennheiser MKE2-Gold, DPA 4060, Countryman B3 / B6 with the flat cap. There is a way to use a non lapel type measurement mic with the SD-75TR kit but I don’t have the details yet. More soon…

Why not just use the RF system you already have?

It’s tempting to think that one might just use their existing RF gear to take measurements, there is an inherent flaw in the concept. 99.9% of the RF systems in the world have what is called a “compander” circuit which compresses the signal for it’s analog trip thru the airwaves & then expands the signal once it arrives at the receiver. Any compander circuit in an RF system will render it useless for accurate measurement purposes. What good is a measurement rig if isn’t accurate?