Today, wireless in-ear monitors are used everywhere from major tours and broadcast productions to churches and local venues. When the technology first appeared, however, it was largely reserved for top touring artists. I had a firsthand view of that transition while working in Artist Relations at Shure, where I helped performers adjust to a completely new approach to monitoring.
The first official wireless In Ear Monitor system for musicians was the Garwood system called “The Radio Station” It was an analog system (analog audio into an analog RF section) released in 1988 and was used by top artists like Peter Gabriel, U2, Roger Waters and Stevie Wonder and Steve Miller. The reason early systems at that time were appearing was that artists began to spread the word that they could save their hearing by not having such high stage volume with instrument amplifier systems in combination with the floor monitor systems.
During this time, these IEMs systems were very expensive and only A-list performers could get them. They were priced around $10,000. About 8 years later newer, less expensive systems became available. They were still analog. For my professional work in the 90’s to the mid 2000’s, I saw the huge explosion in the IEM industry and that time had a huge influence on where IEMs are today. In the late 1990’s, Shure came out with the PSM 600 and shortly after the PSM 700. Sennheiser came out with their 3000 series IEM system around 2000. Both companies competed furiously to get as many artists to use their system. At the same time, Lectrosonics focused on making a wireless Interruptible Foldback system for broadcast talent (interruptible foldback, or IFB, is a related monitoring system commonly used in broadcast production to send program audio and instructions directly to on-air talent) . Shure also at that time also debuted their E1 and E5 drivers which fit into the performer's ear via foam or a plastic seal. Other custom driver companies like Westone, Ultimate Ears, Sensaphonics and Futersonics were gaining momentum as well and they used a network of audiologists to get ear impressions for their customers. This enabled a custom fit which sealed the outside ambient sound better from the listener. The better seal created a better frequency response.
Each driver company was highlighting their material used for the casing and all were offering custom molded versions of their products. Whether people used custom or generic molds, the seal from ambient sound took some time for some artists to get used to because of how isolated they felt. As the Shure Artist Relations manager the one thing I noticed is that it wasn’t always easy for bands to transfer completely over to IEMs. The issue was that one band member tried it and the others didn't. This meant that there was still a battle of loud stage volume. Also, some performers were only putting one of the drivers in their ears. This would cause people to turn up their isolated ear even more because their other ear was battling the ambient sound. This caused quicker ear fatigue in users and we had to remind people not to do it this way to avoid hearing loss.
Luckily, monitor engineers adapted quickly and helped the artist get used to this new approach to monitoring. They learned how to mix in ambient sound to help the artist feel the room more.
Analog systems became more affordable as well as more advanced in the late 2000’s. Many tours consistently had large amounts of systems and more churches began to obtain systems. In a church it was more ideal to have everyone use IEMs at once because those stages needed to have quieter levels overall more than stages in arenas or stadiums. What has also helped the beginner to mid level user overall is that users were now able to control their own mixes via a tablet over Wi-Fi with certain monitor rigs. This made it easier to blend in ambient sound too without a dedicated monitor engineer.
Jumping all the way to 2017, Lectrosonics debuted the first digital IEM system called the M2 Duet which was meant for musicians and broadcast talent IFB. The previous systems were all analog. This digital system is digital audio into an analog RF section. As with digital microphone wireless microphone systems that came out at that time, digital IEMs sounded a lot better and were less susceptible to intermodulation. This meant that users wouldn’t have to work as hard during frequency coordinations to get IMD’s under control like they did with their analog systems. Both digital wireless mic and IEM systems still have an analog RF section. The difference is that the RF carrier's modulation looks different because it’s receiving 1’s and 0’s instead of smooth analog waves.
The problem now is that any digital wireless IEM system will produce latency due to its A to D conversion. For digital microphone systems the latency wasn’t as big of an issue. Microphone systems could have latency around 3ms and it would be ok to the user. The Lectro IEM system was around 2ms latency. It also had Dante capabilities and when you add that together some of the audio reaching the performer might reach over 3ms. For the IEM user this was a problem because now the sound coming out of their ear drivers was delayed with their natural bone conduction of the audio. This did not sound natural to the performer. Over time latency became better both on the M2 Duet IEM side as well as the Dante side, so when it added up, it was better for everyone.
The other issue of deciding to stick with using Analog IEMs or not, was that starting in 2010 going through 2020, we lost 200MHz of RF Spectrum due to the 2 FCC auctions. This made it harder to get large quantities of analog IEMs to work together in one performance area. The reason is that the engineer had to work hard to get rid of intermodulation potential. Less spectrum meant longer coordination work. Before the auctions, it was easier to get things to work because you could spread things out in the spectrum. With less spectrum you now have to calculate for intermods even more. The main reason analog IEMs have more IMD potential is because they are usually rackmounted close together and that is what increased IMD potential the most. That in combination with less spectrum meant that it was harder to get many IEM systems to work together.
Fast forward to today, we have newer digital systems that have latency under 2ms using the digital inputs like Dante or Madi. They include, Lectrosonics M2 Duet, Shure ADPSM and Sennheiser Spectera. They are all flagship systems. With these systems, we can now get over the intermodulation battle as well. In the near future, look for a large push in entry to mid level digital IEM systems.
For musicians and broadcast talent that are new to the business, you will have an easier time getting started with using wireless IEMs or IFB, because more and more engineers are trained on how to get you started. With the introduction of more digital systems, it will take less work to make it sound good.
Wireless IEM and IFB systems have come a long way from the expensive systems once reserved for major tours. Today’s users have access to better-fitting earpieces, more capable wireless systems, personal mix control, improved RF planning tools, and engineers who understand how to deploy the technology successfully.
The result is a monitoring experience that can provide greater consistency, mobility, clarity, and control while helping reduce overall stage volume. There is still a learning curve, but with the right system design, frequency coordination, antenna deployment, and listening habits, getting started with wireless monitoring has never been more achievable