Film-Tech Forum ARCHIVE: Wireless Mic's Setup

This is topic Wireless Mic's Setup in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Paul Konen (Member # 41) on 12-12-2000, 02:36 PM:

What basic equipment is neeeded and where do you hook it up.

I think that you need, of course, a wireless mic setup and a pre-amp. This then get's wired into the input on the amps that run the surrounds.

Anything else or better ideas.

Paul

Posted by Scott Norwood (Member # 30) on 12-12-2000, 02:50 PM:

The easiest way to do this is to get a PA mixer, which generally has both mic preamps and line-level inputs. Then, you just connect your microphone receiver and CD/tape player to the mixer and connect its output to the non-sync input on your processor.

I can't recommend a wireless microphone, though...most of the ones that I have heard were quite bad. Please post here if you find something that's decent. You'll probably have to put the receiver in the booth window to get decent reception, or put it in the auditorium somewhere and run a balanced line to the mixer/preamp.

If you will be doing this often, it's probably best to have a separate sound system (amp and loudspeaker) just for voice work, so that you can avoid damaging the film sound system if someone does something stupid with the microphone set to a high level. (Been there, seen that...the guy blew a $100 speaker diaphragm.)

Posted by Tom Sauter (Member # 616) on 12-12-2000, 03:36 PM:

A separate system (mixer, eq, amp and loudspeaker) is ideal, but I have had good results using a wireless receiver through a line amplifier, and then went directly into the center channel of the non-sync (on a CP50). If the house were steeply raked, I'd use the surrounds instead to avoid putting the mic directly in front of the center screen speaker.

Two recommendations on mics: first, avoid the lavalier (clip-on) type, as they often have highly sensitive condenser microphones in them which are just asking for feedback. Go for a handheld unit with a nice windscreen. Second, go UHF and/or diversity if you can afford it. Lower likelihood of interference, phenomenal range.

You're looking at about $500 list for a basic FM mic (The SHURE "Vocal Artist" is reliable and sounds quite nice). You shouldn't have any trouble getting the signal from one of these 200' to your booth. In the FM diversity world you're looking at $800, and in the UHF diversity market (SONY is my favourite- many touring broadway shows use these) be prepared to cough up a cool grand.

Posted by Barry Floyd (Member # 385) on 12-12-2000, 03:37 PM:

This is actually something I know about. I've worked as a mobile DJ in Nashville, Tennessee for the last 16 years, and wireless mics are what I use to make my living.

As far as a mixer goes.... I'd go with either a Numark or Mackie rack mount DJ mixer. You guys are going "WHAT!!??". But yes, I've seen many drive-in theatres with DJ mixers in the sound rack. The flexibility of a DJ mixer is great. My Numark mixerS have 2 mic channels with XLR & 1/4" inputs, 3 line channels with "preamp" inputs for 6 sources, a "booth monitor send", "stereo master outs", and "stereo record sends".

You could run your non-sync music CD player through the mixer, as well as the mic feeds.\

Which wireless mics to use?? I personally use only Shure UHF True Diversity wireless systems. They're built rock solid, have a great warranty, and the reception is flawless. I've got a SM58 wireless handheld, and a body-pack lavalier set in each of my DJ systems. You can pick up a good Shure wireless system for around $500-$600.00 each.

Posted by Brad Miller (Member # 2) on 12-12-2000, 03:40 PM:

Paul, a quick tip for your theater...make sure the event is in an auditorium using a CP500. That way, you can get whatever mic and preamp you desire and simply run the preamp's line level outputs into the RCA plugs for "non sync 2" and activate it with the push of a button. Works great!

I'm sure Ethan Harper or Jeremy Spracklen will be along shortly with a good mic recommendation, as they do this sort of thing day in and day out.

Posted by Tom Sauter (Member # 616) on 12-12-2000, 03:42 PM:

I think I'm a little off the mark on the prices I mentioned...its been awhile since I've been allowed to spend money on this place

Good call on the Mackie... there's one right next to our MOD V and I'll never let it go!

Posted by Scott Norwood (Member # 30) on 12-12-2000, 05:16 PM:

BTW, if you decide to go with a separate system, Altec made some "mixer/amplifiers" in the '70s that combined mic preamps, a simple mixer, and the amplifier all into one unit. These are nice if you're short on rack space, since they take up the same number of rack units as a Dolby processor. The other nice thing is that some of them (at least the 1606A model that I have) have 70v transformers built into them, so you can get a 70v transformer for the loudspeaker and then run cheap wire to the stage, rather than the expensive speaker wire that you would normally use. The sound quality on these things isn't so hot, but it's perfectly acceptible for voice applications.

The closest thing I could find quickly was this auction on Ebay--only $27.77 with under 2 hours to go:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=519646993

Actually, this is just a mixer/preamp, but it would do what you want if you intend to connect it to the non-sync input on your Dolby unit.

Posted by Randy Stankey (Member # 64) on 12-12-2000, 05:23 PM:

I've done this a couple of different times in a few different places...

On a Ultra*Stereo processor there's an "AUX" input on the back of the unit. It takes a regular line level input, such as that from a CD player and puts it to the right and left channels. All you have to do is press the proper button on the format module.

We have had a company come in and do satellite feeds in the auditorium. They brought their own projector and receiver. They fed the signal into a regular old mixing console. There was a handle for the sound and they had a mike as well.
Program your individual inputs on "sub" masters and use the "grand" master to vary the overall level. That way you can make sure the mike and the audio feeds are balanced, loudness-wise.

Just make sure you have the output of the mixer turned DOWN before you try it. You can always slowly turn it up. It's a lot harder to turn it down after you've blown out your processor!

The other place I've done this is in a regular "stage" theatre. They use a DSP to send the outputs to the speakers, though. All you have to do there is hook all your mikes up as normal and then flip a switch on the back of the computer. The DSP does all the work.

Just make sure you do a walk test before you are ready for your "Go-Show". You can have a lot of feedback because the speakers are behind the person speaking on stage. You'll have to play with the levels to get that "happy medium" where the voice will be loud enough but it won't cause feedback.

Try to set up a podium and keep the mike on the podium. That'll force the person speaking to stay in an area that you know will be safe. They won't walk in front of a speaker and "screech-out" the room that way. It's nigh on impossible to tell your average person that they can walk in one place and not in another... especially while they are trying to give a lecture or performance. Most people can't think on two levels at once like that!

If you just use a little common sense you souldn't have too much trouble.

Posted by Sean McKinnon (Member # 612) on 12-12-2000, 11:36 PM:

This may sound totally stupid and not make any sense to the discussion but at my old theatre our walkie talkies would not work in the booth sometimes and someone said it was 'cause of the lamphouse radiating RF energy would this disrupt a wireless mic setup in a theatre?

------------------
I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by Randy Stankey (Member # 64) on 12-12-2000, 11:45 PM:

Yes, I agree with that. I have had the same experience. At Mercyhurst College we couldn't use our "walkie talkies" when the projector was running. Turn it off and you were back in business. Sure, they were 27Mhz cheap-o things from Radio Shack but just the same, they only worked when the lamp was off. We didn't have too much trouble, though. The theatre had Clear-Com (A hard wired system) and the base station was in the booth. No biggie... just turn on the "beeper" and when somebody calls, beep-beep!

They say the ONLY kind of wireless system that's immune to this kind of interference is the kind that uses wires!

At Cinemark we use two-way radios on the FM "business" band. We never had interference problems.

To bring this topic back around to the subject at hand: When you're doing your test before your "Go Show" make sure you test for interference, too!

Posted by Aaron Sisemore (Member # 145) on 12-13-2000, 12:58 AM:

I will concur with Scott. The best way to add a microphone to a cinema sound system is to *NOT* add a microphone to a cinema sound system. The risks are just too great for damage to the speakers and amplifiers from the inevitable 'know-it-alls' and 'plain idiots' that will pop up. Get a separate PA system for the microphone. You'll be glad you did.

Aaron

Posted by Trevor Bailey (Member # 75) on 12-13-2000, 05:45 PM:

I forget what the format numbers are, but the CP500 has PA formats build in for both center and surround.

Randy,
On the topic of two way radios, I worked at a theater a few years ago that used Motorola Spirit (I think that was the name) radios. When you were in the soda room and tried to transmit, some of the pumps would activate. Damn funny joke to play on the new kids!!

Posted by Randy Stankey (Member # 64) on 12-13-2000, 09:00 PM:

I used to be an overnight security guard in a 400 room hotel, while I was in college. We had Motorolas. Let's just say I've set off more than one fire alarm... accidentally, of course! (The alarm system was rather antiquated.)

Posted by Mark Gulbrandsen (Member # 72) on 12-14-2000, 04:47 PM:

Check out the Audio Technica ATW-1400 Wireless systems on our web site under the whats new heading on the Motion PIcture Page. For 250 bucks you get a UHF system with a true diversity receiver, and a body pack transmitter. 2 Receivers will rack mount into a standard 19" rack and the mounting ears are included. The antennas are on the front panel of the receiver, not on the back so they end up inside the rack(and shielded). The cardiod mic is another 30 bucks. This system works great in theaters, through brick walls, and metal buildings. The performance is as good as units costing in the 700.00 to 1K range. The main thing is if you get a wireless mic get a UHF system. VHF simply does not travel as well through walls, especially metal walls. We have traveled up to a block away and inside other buildings with this unit when we were initally testing it out. A hand held transmitter is also available.
Mark @ GTS www.getgts.com