For most churches, coordinating frequencies for wireless systems after the DTV transition on June 12 probably required little (or maybe no) testing and tweaking. Worst case, replacing an aging system or two.

But what happens when you're responsible for 151 channels and are expected to deliver a flawless audio experience for the 23,000 worshippers attending weekend services? For the answers, we turned to Willow member, former full time staffer and audio consultant Nathan Miller who helped the megachurch navigate the channels.


How many channels of wireless are you running simultaneously?
We run a total of 66 channels in our main sanctuary:
• 18 Personal monitors
• 28 UHF-R systems
• 11 UHF J4 systems
• 4 Lectrosonics® bodypacks
• 2 Telex® BTR analog intercoms
• 3 Lectrosonics IFB (interruptible foldback) T1 systems

Campus wide, we run 151 channels, all coordinated.


Did you have to replace many 700 MHz systems in the DTV transition period?
Over 50% of our main sanctuary inventory was over in the 698MHz category, most of our personal monitors were HF band, and many of our mics were UA.

Did you need to re-coordinate your frequency set-ups after June 12?
We saw this coming and planned our budget for 2008 to begin removing everything over 698MHz out of the main auditorium. Throughout 2008, we purchased 28 channels of UHF-R to replace the UA and UB mics in the sanctuary. We took this opportunity to increase our spectral diversity as well. We currently have mics in G1, J5, J4, M4, UB and X1 bands across campus, hoping to mitigate the overall impact of future FCC rule changes.


We also removed personal monitors that only had frequencies A-B selectable to a solution that was tunable in 25Khz increments across a wider frequency range, allowing us to put more channels in the band.

Come June 2009, we didn't 'need' to re-coordinate as most of the DTV in Chicago was already on air, however we did to gain a more robust frequency scheme. This coordination increased the spectral 'buffer' between our mics running at 10mW, personal monitors running at 100mW, and even higher power IFB's, which run at 250mW. I ran tests all along, and still run tests every 2-3 months.

What tools or special services were involved? In other words — how did you do it?
We didn't hire any outside consultants, I did the majority of the coordination (I was a full time staff member at the time) with help along the way from some contacts I have at Shure. I also made calls to Shure's Applications Engineering group.

I used Professional Wireless IAS software to handle the 'theoretical' coordination, and then just took the time to apply and test all of it. 75-80% of it worked, the other 25% was a lot of testing and tweaking. Once a device was coordinated I would turn on all the devices and go one by one turning them off then on to check for worst-case scenario intermod. This takes a lot of time, but is well worth it. We have not had a RF failure on a microphone in the main sanctuary in over four years. The majority of failures we have are element related, followed by hardware issues.




Chicago-based ABC affiliate WLS-TV broadcast on VHF Channel 7. Coverage problems forced them to switch to UHF Channel 44. Were you aware of it in advance?
Funny you should ask. I don't live in the Chicago area anymore, so I wasn't aware of the change before it happened. We had five channels of G2 personal monitors in that 6MHz ... all were unusable after that.

We're in the process of handling it now. The trouble is, we're pretty stacked spectrally, so it's not a straightforward re-coordination. We did manage to get one channel of the five back, and we moved two of the remaining four channels to another location on campus that didn't have the IMD restrictions of that high channel count room. We will probably do that with the other two channels in the near future.

What kinds of batteries do you use in your wireless systems? Alkaline or re-chargeable?
We only use alkaline. Hundreds of AAs and 9 volts. If there was a reliable method of managing rechargeable in terms of battery life, how often a battery has been recharged, we'd probably consider using them. But with all the systems we have, it represents a serious management issue. We spend a lot of money on alkaline batteries.

Any tips for smaller churches on getting maximum reliability from wireless systems?
Buy good gear. Don't get the cheapest solution. It will cost you more in the long run.



At Willow, we still use the same UHF series mics in the main auditorium that we bought 7 or 8 years ago. We have definitely gotten our money's worth. We have, on the flip side, made the mistake of buying slightly cheaper gear, which on average returns us two or three years of use at best.

Also, with wireless — pay attention to detail. Many times a series of seemingly small compromises can cause a system failure. Poor antenna placement coupled with poor antenna cable is a good example.

About Nathan Miller:
Combining a passion for working with artists with a penchant for troubleshooting the audio chain, Nathan presently consults with Willow Creek Community Church. An audio engineer for twelve years and a Willow staffer for five, he and his wife relocated to small town life in Indiana after several years of urban living in the Chicago area. He continues to work closely with the church, chiefly in the role of monitor engineer.