FREQUENTLY ASKED QUESTIONS
What is wireless interference, and how do you manage it?
Dictionaries define wireless interference as; “Any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronics and electrical equipment.” In professional audio, any undesirable audio output signal from a wireless device is usually referred to as interference, as is any “dropout” or interruption of desirable audio output. It can be caused by many things, but the most common sources are TV broadcast stations, other nearby wireless audio equipment, improperly operating computers and electronics, video equipment, lighting equipment, defective or improper cables, and faulty or poorly placed antennas.
An integral part of our process is observing the RF environment at your location with sensitive instruments and using that data to define “clean” frequencies for your wireless equipment to use. Our method performs billions of calculations to reduce the possibility of intermodulation interference that your equipment can generate when certain combinations of frequencies are used. We also consult several databases to ensure that your frequencies do not occupy prohibited clear channels, such as those public safety channels used in major US cities that are not listed in FCC broadcast TV databases.
What is intermodulation and why should I care?
Intermodulation distortion has a lengthy and complex explanation here. Put simply, as it relates to wireless professional audio equipment, it is interaction between multiple radio frequencies that generate other, undesirable radio frequencies called products. These products cause interference when they coincide with frequencies that your equipment is using. The interaction occurs inside the electronics of transmitting equipment like microphones and IEM’s. This is because transmitting antennas also receive signals and inject them into the transmitting equipment, where all of the signals can interact, amplify, and be re-transmitted. Intermodulation also occurs in the front-end electronics of receiving equipment. Fortunately, intermodulation distortion products are highly predictable when all operating frequencies are known. We use mathematical algorithms to perform the predictions and generate a number of frequencies that can operate together without their intermodulation distortion products causing interference.
What do I need to do to begin using your services?
How much do your services cost?
Please contact us so we can talk about your needs and work out the details. Our prices are reasonable, and we want to work with you! We've been serving technical needs of the entertainment industry for decades and we completely "get it."
Absolutely FREE. Call us to discuss your needs, details about your equipment, and your location. If this is your first time calling, we’ll access all of the
relevant FCC frequency databases for your location and perform intermodulation calculations to generate a list of frequencies for your specific gear,
based only on the FCC data. Although this is not as reliable as our on-site spectrum analysis-based paid services, we can often solve your immediate
interference problems without charging you a cent.
On-site RF Technician services:
Please Call us to discuss details about your event, schedule, equipment, venue location, travel arrangements for our staff, and cartage for our RF instruments & equipment. We strongly urge you to contact us well in advance of your event. Our on-site RF Technician will work with you to contact all parties intending to operate wireless equipment at your event, in advance, and will cooperate with your local Society of Broadcast Engineers Frequency Coordinator or FCC Frequency Coordination Committee if applicable. We can help your contractors design and implement their systems to best fit your production requirements. Our goal is to provide a complete, comprehensive plan to assure perfect performance of all wireless equipment operating on-site.
If it's related to wireless audio equipment, we can usually help. Wide area coverage, antenna distribution systems, aesthetic appearance, and challenging environments are all within our realm. Our bag of RF tricks is deep, and we offer some unique and effective solutions that few others are aware of. Please contact us to find out!
What audio equipment frequency ranges do you specialize in?
We typically deal with systems that operate in the VHF TV band (54 MHz to 216 MHz), the UHF TV band (470 MHz to 698 MHz), and the 900 MHz ISM band (902 MHz to 928 MHz). Our services are versatile, and our equipment and methods work well with equipment operating on legal frequency bands in the USA.
Why not use free online RF coordination utilities offered by the manufacturers of my wireless equipment?
Free software tools that wireless manufacturers make available to their customers are much better than no planning at all, but they suffer from some shortcomings. In rural areas, they are sometimes sufficient, but at urban or suburban locations they are very often inadequate. Most of these utilities rely on data provided by the FCC that reports licensed broadcast television transmissions purported to be operating at a location defined by you. Unfortunately, this information is often incomplete and/or incorrect. We have posted a case study showing a real-world example of this.
Another drawback is that some RF apps are limited to defining frequencies that are specifically suited to the equipment that their host companies manufacture, or they depend on you to define the performance characteristics of each off-brand model that you wish to use. This requires practical RF engineering knowledge to implement correctly. Reliable RF coordinations must integrate the behavior of every transmitted frequency operating in close proximity, no matter the make or model of the equipment.
An important step in a reliable RF coordination is to directly examine the RF environment at your operating location with precise equipment and use that information as a basis for the required calculations. That’s exactly what we do.
Can’t I just buy professional software and do it myself?
Of course you can! But most professional software packages suffer from the same weaknesses noted above. We use many of these products as part of our process, but we combine them with other proprietary tools, methods, and decades of experience to overcome their limitations. There is a great deal of expertise involved in RF coordination and much to learn before one can trust any of the available software for reliable results.
Also, a thorough RF coordination is time consuming, even for experienced professionals with all of the best equipment and software. If you’re a working audio engineer who needs to use your time efficiently to concentrate on doing sound and not chasing wireless interference, please let us perform your RF coordination for you.
Should I buy the newest technology that automatically “self-coordinates” in the UHF band and has fail-safe redundant frequency switching?
If you can afford it, that system is absolutely amazing and represents the pinnacle of wireless microphone technology. Its stunning capabilities are matched by equally stunning prices, and it can cost more than $5,000 per audio channel when equipped with all of the accessories required to make it fully functional and reasonably fail-safe.
We can RF coordinate dozens of channels of conventional UHF equipment for you many times before you will spend the cost of a single audio channel of autonomous self-coordinating UHF equipment.
Do you guarantee interference-free frequencies for my equipment?
No one can truthfully make that guarantee in the USA. FCC rules for unlicensed wireless microphone usage practically mandate this.
Even if you use the autonomous equipment described above, completely fail-safe wireless audio gear is impossible in today’s radio environment. This is because the combination of current legislation, (lack of) enforcement, the easy availability and widespread use of potential interference sources, uneducated or careless operators, technological limitations, and natural phenomena fill the RF environment with constantly changing and unpredictable sources of interference. It is worth noting that wireless technologies intended for military, aviation, and other life-critical applications do enjoy robust protection measures, but professional audio equipment categorically does not. Even Broadcast Auxiliary Service licensees often suffer from interference in spite of the limited protections of which they are entitled.
Excellent examples of interference sources are some LED video panels imported from overseas that lack FCC certification or are falsely labeled as certified. These products are becoming ubiquitous in the entertainment industry. Many of them emit strong RF energy across the entire UHF TV band, sometimes intermittently, and can disable or severely degrade the performance of every piece of wireless audio equipment within 100 feet. Other examples are roaming television news crews entering your location and activating their own wireless microphones, cameras, and coms without consulting your staff, or a remote radio station broadcast booth setting up wireless mics right outside your venue.
As mentioned before, no one can guarantee against those possibilities, but our services give you frequencies least likely to suffer from interference and will put you in the best possible situation to deal with problems quickly and effectively. Our RF analysis and troubleshooting efforts will detect local interference sources and help you eliminate or avoid them.
Should I hire an RF Tech to work on-site?
YES! Hire Clean Wireless Audio LLC and enjoy trouble-free wireless at your event!
My wireless equipment will only operate on one fixed channel per unit. Can your services help me?
Our services are most suited to the use of professional-level equipment that is capable of tuning to many channels. However, our services will reveal whether or not your devices will operate well in your RF environment and if they will operate well while operating simultaneously. We can determine which units may or may not need to be replaced and offer suggestions to help you avoid acquiring incompatible replacements.
My wireless equipment operates in the 2.4 GHz, 5 GHz, 6 GHz, or 900 MHz band, and is “self-coordinating” or “frequency-hopping”. Are your services suitable?
The new wave of equipment on the market that fits this description can benefit from RF Coordination if you intend to operate it simultaneously with other conventional VHF or UHF wireless systems. 900 MHz equipment that is not “self coordinating” or “frequency hopping” is treated the same as any other conventional UHF wireless equipment, and coordination is highly desirable.
© 2014 Clean Wireless Audio LLC