Audio
Shure ULX troubleshooting
The Shure ULX problems live-event techs bring to Ask Roadie most. Pick your symptom, or describe your own in plain words, and get the likeliest fix first, with the manual page when there is one.
Common ULX errors & problems
What techs run into most, and what's usually behind it. The step-by-step fix for your exact unit is in Ask Roadie.
- Step-by-step fixGet the fix →
What batteries does ULX use and how long do they last?
Likely cause: Runtime and the on-screen fuel gauge are specified for the 9V alkaline/lithium discharge curve; lower-voltage chemistries hit the converter cutoff sooner and misread the gauge.
- Step-by-step fixGet the fix →
Constant hash, buzz, or noise even with a strong RF signal
Likely cause: Switching supplies and LED drivers radiate broadband UHF noise the receiver demodulates as hash; changing frequency and increasing physical separation moves the link out of the interference.
- Step-by-step fixGet the fix →
How do I connect ULX receivers into a rack and console?
Likely cause: Correct output level and a locking DC connector prevent noise/clipping and accidental power loss, and antenna/power distribution keeps a multi-receiver rack tidy and interference-free.
- Step-by-step fixGet the fix →
How do I set up several ULX systems together without interference?
Likely cause: A Group is a factory-computed set of frequencies with minimal intermodulation products, so drawing channels from one Group avoids the sum/difference frequencies that cause dropouts and hash in multi-system setups.
- Step-by-step fixGet the fix →
Battery meter reads low or the pack dies fast even with a charged rechargeable
Likely cause: The gauge maps voltage to bars assuming an alkaline curve, so a lower/flatter-voltage chemistry reads inaccurately and reaches the converter cutoff sooner.
- Step-by-step fixGet the fix →
Is this ULX still legal to use in the US? / Which frequency bands are allowed?
Likely cause: The FCC reallocated the 600 and 700 MHz spectrum to broadband; mics in those ranges cause and receive interference and are prohibited.
- Step-by-step fixGet the fix →
RF dropouts, static, or signal loss when the performer moves
Likely cause: ULX uses predictive true diversity, so performance depends on at least one antenna keeping a clean path; metal and video walls reflect/absorb UHF and co-located antennas starve each other, which placement and distribution fix.
- Step-by-step fixGet the fix →
Transmitter and receiver will not link even on the same group/channel
Likely cause: Group and Channel numbers are relative to each band's frequency table, so identical numbers in different bands are different actual frequencies and mismatched-band units never share a carrier.
- Step-by-step fixGet the fix →
How do I update the firmware on classic ULX?
Likely cause: The analog ULX platform predates networked firmware; only the later ULX-D digital line is field-updatable.
Not on the list? Describe it your way, or paste the error code off the display. Ask Roadie works the problem with you until it's fixed or you have a clear next move.
How Ask Roadie helps with the ULX
- 1. Pick the Shure ULX. It's already in the list.
- 2. Describe what you're seeing. In your own words, or the error code off the screen.
- 3. Get the likeliest fix first. Steps in order, the manual page when there is one, and a note when other techs have confirmed it.
- 4. Still broken? Tap 👎 and it keeps going from where you left off.