Crackling, muting, or a dead channel on a wireless handheld or lav almost always traces back to one of three things: power, RF interference, or line of sight. Work through them in this order.
1. Batteries first
Fresh, matched batteries — not "still had some charge left" batteries. Mixing a half-used battery with a fresh one in a bodypack causes exactly the kind of intermittent dropout that looks like an RF problem. Swap both cells, not one.
2. Line of sight to the receiver antenna
Metal (ductwork, stage risers, the pastor standing behind a metal music stand) blocks or reflects RF. If the dropout happens in the same spot on stage every time, it's a physical obstruction, not a frequency problem — check antenna placement and try repositioning the receiver or antenna higher and with clear sight to where the talent stands.
3. Frequency conflicts
If dropouts are random rather than tied to a location, another device may be sharing or nearing your frequency:
- Guest bands or traveling speakers bringing their own wireless gear on the same day is the most common cause.
- Nearby cell towers, other churches' systems, or venue Wi-Fi in the 2.4GHz/5GHz range (less common but possible with digital wireless) can interfere.
- Re-run your system's frequency scan/coordination utility if you have one — most digital wireless systems (Shure, Sennheiser) have a "scan for open frequencies" function in setup. Run it fresh each time a new system might be operating nearby (weddings, community events, touring artists).
Antenna distribution systems
If you're running more than 2-3 wireless channels, don't run separate "rabbit ear" antennas per receiver. Use an antenna distribution system so all receivers share a coordinated pair of antennas — this is usually what fixes chronic, hard-to-diagnose dropouts in bigger systems.