Sennheiser EW 500 drop out

[Troy Tiscareno]

Squelch is the term used in radio (and these are radio transmitters), but the same idea in the audio world is called a "gate," if you're familiar with what that is.

It is understood that anytime you are using radio frequencies, there is some background signal that the receivers will pick up. Even without all of the man-made radio energy, our little planet is being bombarded with radio waves from space, so there is always something. In practice, there will often be faint signals being picked up from distant (or not-so-distant) transmissions). But we don't want to hear or record this background noise, right?

The Squelch lets you set a volume threshold that must be met before the transmitter transmits or the receiver sends the received signal to its internal amplifier. By adjusting the squelch above the level of the background noise, that noise isn't transmitted unless someone is talking into the mic at a volume higher than the squelch level, and then it will be masked by that person's voice. As soon as the person stops talking and the volume drops down below the squelch threshold, the transmitter no longer transmits, and the circuit goes quiet.

The problem comes if the squelch is adjusted incorrectly. Too low, and the background noise may become loud enough to cross the squelch threshold and get transmitted, adding unwanted noise to your recording. Too high, and the person who you're trying to record will get cut off whenever their speech volume drops below the squelch threshold, which will sound kind of like an intermittent connection.

Normally, you adjust the squelch down until you can hear the background noise, then bring it up until you hear the squelch circuit cut out the noise. Add another 10% or so just in case the background noise gets louder later on, and then test it by speaking softly into the mic. If the mic picks you up okay even at low volume, you're all set. If you're getting cut off when your voice is too soft, then you need to back off the squelch a bit.

Once set, you should rarely have to adjust your wireless gear, and if/when you do, it should be only a tiny tweak up or down.

-Troy

[Richard Lewis]

Thanks Troy. Your explanation is very much appreciated.