Please review this link as a further explanation on topics that are covered in the document below: http://www.churchproduction.com/story/main/a-small-churchs-guide-to-working-with-wireless/3
As the environment is the biggest factor in wireless audio performance, there is a chance that certain environments and circumstances will not allow for satisfactory performance. This can be verified by successful performance in a different environment.
This is an extremely informative video on how all wireless gear works in a WiFi rich environment
Note: If you have multiple members in your band with Line 6 wireless, everyone needs to be on the same RF mode.
Pre-Qualification: First Things To Rule Out:
- Use the factory power supply
- Try on more than one channel!
- Try in more than one place/venue
- Check the transmitter LEDs during drops/interference. RF dropouts result in the green LEDs going completely off. Even one green LED means the signal is present and something other than the wireless system is causing the problem. If you see full red LEDs followed by quickly shifting back to green, it means that the system has re-synced (normal if the dropout is too long). The red LEDs come on only if the intended signal from a Line 6 transmitter is not present. In this case, they are showing RF competing for the same space.
Interference:
Symptoms
- Reduction of RF LEDs on the front panel that indicate usable RF signal strength
- Audio signal muting
Possible causes
- Trying to function at too great a distance
- Having unintentional transmitters, such as walkie talkies or in-ear monitors, too close to a receiver
- Significant amount of close-by RF signals within the same 2.4GHz range (Wi-Fi, microwave ovens, etc.)
Suggestion
- "Walk test" your system in advance of an event over the entire desired range to verify that sufficient RF signal is available to avoid mutes from occurring
- With transmitter off and receiver turned on, scroll through the channels. Red LEDs indicate stray RF on that channel. Choose channels that exhibit the least red LEDs. Note: Line 6 wireless WILL still operate but at reduced range.
Decreased Range
Symptoms
- Reduction in range in general
- Reduced range indoors vs. outdoors
Possible causes
- Blocked "Line of Sight" between the receiver and the transmitter
- Barriers such as walls or air-curtains can impede the path of radio waves
- Transmitter strength reduced if it must pass through walls
- Transmitting through earth (receiver in basement)
- Human bodies absorbing RF energy
- Receiver is very close to other intentional radiators in the same frequency band such as Wi-Fi wireless access points
Suggestions
- Improve "Line of Sight"
- Elevate the receiver
Weak Audio (thin audio output compared to other wireless systems)
Symptom
- Weak and/or noisy audio output
Possible causes
- Gain/trim settings on mixer need adjustment
- Plugging into a "line level" input
- Plugging into a channel with pads engaged
- Using a TRS plug in the 1/4" unbalanced output
Suggestions
- Adjust gain/trim as if using a wired microphone
- Connect the XLR output on the receiver to an XLR input on the mixer
- Use a mono plug in the 1/4" unbalanced output, never a TRS plug
Dropouts ("Audio" vs "RF" dropout: different paths to correct)
Symptoms
- Audio signal interrupted
Possible causes
- Local conditions in one or more venues, e.g. a large Wi-Fi installation in close proximity, metal walls/roof
- Instruments or amps being used are faulty
- Signal chain issue
- Blocked "Line of Sight" between the receiver's antennas and the transmitter's antennas
- Other XD-Vs/Relays operating on the same channel
- Receiver near any transmitters such as walkie-talkies, In-Ear Monitors, etc
- Using a substitute power supply
Suggestions
- Try a different venue to reproduce problem
- Try multiple instruments/amps to reproduce problem
- Trace signal through chain one component at a time. "Audio" LED lights when signal is received.
- Improve "Line of Sight" by moving receiver to 6-8 feet high while avoiding obstacles such as metal posts, walls, etc.
- Ensure each system has its own unique channel to operate on
- Move intended transmitter closer to receiver than unintended transmitter to eliminate "near/far" issue.
- Provide ample distance between the receiver and other transmitters. The distance will depend on the strength of the transmitter and the gain of the transmitting antenna.
- Use the factory power supply or one that can supply the required 9v DC current. If you are using a pedalboard supply, it must be able to supply this amount of power to the receiver in addition to whatever else you have plugged into it.
Q: Does USB 3.0 create interference in the 2.4GHz frequency range?
A: USB 3.0 computer cables and peripherals, including hard drives, are known to emit radio frequency interference throughout the 2.4GHz band, which results in reduced range and/or performance for any 2.4GHz device in its proximity (including wireless keyboard or mouse, WiFi, etc.). We recommend placing any digital wireless receivers at least two meters away from the USB 3.0 device and its cabling.
Below is a link to a study by Intel regarding this interference.
http://www.intel.com/content/www/us/en/io/universal-serial-bus/usb3-frequency-interference-paper.html
References for working with wireless systems
http://en.wikipedia.org/wiki/Non-line-of-sight_propagation
http://www.djsociety.org/Wireless.htm