Wireless system for use in RF Hell

[John Moran]

The application is pretty simple, it's spoken word, not music.

BUT

This is pretty important and occasionally historic stuff. Last night was one of those historic occasions and I'm tired of the videots screwing up the audio. Here's the kicker:

The venue is a hospital conference room which changes everything you would expect. I can't begin to count the variety of RF sources in that room and the folks who are shooting the video have been using a Sony VHF system that has frazzed on me and that has driven me to the point of getting my own wireless system for my feeds. This scenario requires a high level of interference rejection and possibly on site channel selection because I don't know what the hell is in the air there and it can change.

Interestingly, outside cell phone service is blocked inside the building except for their own system which accommodates thousands of pagers, doctor phones and other pda type devices. Apparently they have some serious RF things implemented and I don't think any one person on staff has a total clue as to everything that is in the air. That's not counting various MRI, CT Scan and other high powered medical toys that radiate everything imaginable, even with shielding.

Hardwiring the lav on the speaker is not a viable option. Wireless is mandatory. I've worked with prima dona artists and some of these doctors qualify for that realm. When they are renowned invited speakers from around the world speaking to equally renowned researchers, they get what they want. That's fine, they're truly brilliant folks who save peoples lives, they deserve it and a lot of these folks are quite cool in person. I want it done right, too. It makes my life easier in post.

SO..... I was thinking UHF and switchable channels for the xmr and rcvr so I could adapt to the situation as it changes. I have a couple of Sanken COS-11 lavs that are wonderful so the system doesn't necessarily need to include the mic but I'm not discounting a mic included in the system if it makes my life easier and it's more realiable.

Suggestions ?

[Testing123]

Is this a situation where everyone (including the speaker) is sitting around a conference table, or is the speaker at the front of the room with a lectern?

How are you going to change channels on the fly if the interference situation changes during a meeting? Even if you could, you already will have lost audio, and what if you couldn't quickly find another useable channel?

A wired gooseneck mic is out of the question? Seems like wired is the only really bulletproof solution here.

[John Moran]

Originally Posted by Testing123

Is this a situation where everyone (including the speaker) is sitting around a conference table, or is the speaker at the front of the room with a lectern?

Speaker at the front of the room with audience and they tend to wander away from the lectern. If they stayed at the podium, which is mic'd, there would be no issue and life would be rosy but they wander around.

Originally Posted by Testing123

How are you going to change channels on the fly if the interference situation changes during a meeting? Even if you could, you already will have lost audio, and what if you couldn't quickly find another useable channel?

Not planning on doing it on the fly at all, I want to be able to find a clean frequency prior to the event. That frequency might or might not change day to day, but once it's up and the show is on, nothing changes and we get what we get. I think a UHF system might be better from an interference standpoint but I'm looking for some confirmation of that and recommendations for a suitable system from someone who has lived with these things on a regular basis. I've had some cheezeball Audio Technica wireless systems in the past but this requires the good chitt. I've used some Sony UHf that seemed to be pretty good, but they were a rental for a parade broadcast and I only lived with them for a day or so.

Originally Posted by Testing123

A wired gooseneck mic is out of the question? Seems like wired is the only really bulletproof solution here.

It ain't a perfect world, is it. Like I said, these guys want to do what they want to do and we make it work as best as we can just like any other live performance.

At least they don't lip sync (even tho' that would be easier for us).

[Jim vanBergen]

Normally, I'd tell you to go Sennheiser, 3532 Receiver with an SK-50 transmitter. These are what I have used in hospitals for Discovery Channel shows with excellent results. There are rented and frequency-coordinated specifically for the event.

But, as you're looking to buy, I'd consider looking into a digital wireless system, such as the Zaxcom 900. I'm sure there are others in the marketplace, but as you will have extreme RF hash from the medical devices in the RF spectrum, it's worth a look.

The other really useful thing would be to have a scan done within the room.

Hope this helps!

[John Moran]

Originally Posted by Jim vanBergen

Normally, I'd tell you to go Sennheiser, 3532 Receiver with an SK-50 transmitter.

I looked at those and the Sony WL800 and UWP series product lit last night. The exchange rate really jams the prices on Sennheiser these days, not that they were ever inexpensive. I think I like the small receiver sizes that Sony offers versus a rack unit.... I think... but I don't know yet. It definitely suits the pack for the current gig better than a rack piece would, but I also have to consider future uses. There is a substantial price difference between the high end Sony WL and the high end Sennheiser 3000/5000 series. I'd like to compare them side by side.

Originally Posted by Jim vanBergen

But, as you're looking to buy, I'd consider looking into a digital wireless system, such as the Zaxcom 900.

-Johnny Carson voice- : I did not know that.

Good call, totally forget they existed.

Originally Posted by Jim vanBergen

The other really useful thing would be to have a scan done within the room.

Hope this helps!

and the budget to do the scan is coming from.... uh ..?
oh, there it goes.

eh, I'll make something work.
I need to get some demo time with the Sony and Sennheiser and check out the Zaxcom.
Yes, this was very helpful, thanks.

and now back to the editing and cleanup of the very impetus for this quest, a great thing to do on a cold, rainy night.

[XLR]

I'm not familiar with the problem, but our renting place for safety issues allways prefer the Sennheiser system over the Sony, although they're authorized Sony dealers.
And they've sorted out all AKG stuff because of interference problems.

[Jim vanBergen]

-Most manufacturers also offer a compact receiver designed to mount on a handheld camera and battery powered.

-I also did not mention Lectrosonics, which also have very good RF integrity.

You can often find RF techs willing to do an R scan for as little as $500. you might call the local radio or TV stations and talk to their engineering department and see if they have an RF engineer who will moonlight & do a scan for you. It may be cheaper to rent several wireless mics and try them out, but seeing the RF spectrum on an analyzer can be invaluable. I know, money is always tight, but if they can afford a 10 million dollar CAT scan machine, maybe they will budget an extra grand or two or A/V next year. You can always ask.

Hope this helps!

[John Moran]

Originally Posted by Jim vanBergen

I know, money is always tight, but if they can afford a 10 million dollar CAT scan machine, maybe they will budget an extra grand or two or A/V next year. You can always ask.

The hospital is not the one footing the bill; even worse, the available split feeds from the in house A/V dept. are covered in ground hum. (ponder that for a second ) That's why the speakers are now being double mic'd. I'd like to get that part right instead of depending upon whatever lavs shows up with the video crew which have been unpredictable and inconsistent.

What are the hidden pitfalls with the digital wireless rigs? I've never used one and have no clue.

[Cosmic Closet]

John,

If you can't get a scan done, may I suggest doubling up on wireless mics?

Use a dual-clip for 2 UHF mics, each set to different frequencies that you have tested and have a good feeling about. At the very least you have now increased your odds by 50% that one channel may stay clean throughout.

Run one mic lower than the other, to minimize phasing, but just so it is ready to take over if No.1 starts having problems.

As long as the docs don't mind wearing two belt packs instead of one (I know doctors can be finicky about all this stuff) you should at least have a better fighting chance.

The latest 'intelligent' Shure UHF mics are very nice and clean; I get feeds for video from them in many gov/corporate technology offices and have not had any issues with noise or drop-outs.

Best of luck,
Claus.