Wireless Mikes "banging."

Stevens R. Miller

Well-Known Member
We're doing a middle-school musical production that uses fifteen wireless mikes (some Audio Technica series 3000, some series 2000, and mix of ATW-310 and ATW-210 body packs). Some of our actors were wearing their packs at waist level, behind them. In scenes where those actors put their hands together behind their backs (or, in the case of my son, who is playing a parrot, when he held his hands underneath his tail feathers), it caused a number of loud "banging" sounds, kind of like highly amplified pops.

I'm wondering what the cause could be and, of course, how to solve it. What puzzles me first is that I can't imagine how manipulating the transmitter case could lead to sound at the receiver, unless there are unreliable electrical connections involved. The actual microphones are all over-the-ear boom sets. We've certainly had some issues with the wobbly booms whacking the actors' faces, and that also causes unwanted sounds, but those are easily recognized as more muffled "whomps," rather than "bangs." Here, the issue only seems to come up when it is the transmitter case, not the microphone, that is jostled.

Any ideas?
 
I second the loose connector or strain relief issue. It might not be a bad idea to take a look at those troublesome body packs/cables to see if you can replicate the issue after a rehearsal. If so, the cable might have been bent too much by the strain relief causing a break in the cable. Do you have belts that the body packs are dropped into and then secured to the actor(s), or are you taking the packs and attaching directly to the costume/actor?
 
I second the loose connector or strain relief issue. It might not be a bad idea to take a look at those troublesome body packs/cables to see if you can replicate the issue after a rehearsal. If so, the cable might have been bent too much by the strain relief causing a break in the cable.
I will try to get in early before today's show and pursue this. These things do take a beating. Then again, for what they cost, I'd expect to be able to pound on them with a hammer and not damage them.
Do you have belts that the body packs are dropped into and then secured to the actor(s), or are you taking the packs and attaching directly to the costume/actor?
The latter, with surgical tape. The costumes are mostly full-length kaftans/body-suits. Some of the kids do have clothes with belts under their costumes, but a lot of them don't. My wife would have to tell you what the girls in the (respectably modest) two-piece harem outfits do with their packs.

This sounds abusive to the equipment, but if I do confirm the problem is at the connector, how bush-league would it be to wrap the cable around the pack once and tape it that way before attaching it to the actor? That would put strain on the wire at the connector, but it might at least keep it firmly in a working configuration for the duration of the show. I don't want to accelerate their final demise, but, if they're already intermittent due to breaks or bad connections, their demise must be imminent. I shudder to think what the principal will say when we tell him how much it's going to cost to replace all these things...
 
You can give it a shot, and if the Macguyver approach works to get you through this run, great. However, from my perspective, as soon as I notice this occur during a rehearsal or performance (god forbid), I will swap out cables, no question. To me, even the possibility of getting those cracks/bangs, is scary enough to interrupt a great performance otherwise.
 
I will try to get in early before today's show and pursue this. These things do take a beating. Then again, for what they cost, I'd expect to be able to pound on them with a hammer and not damage them.

I definitely feel you there. That's why whenever I order new mic systems or a replacement cable, I always spec the Duramax 2mm for our E6s. I know it's more obvious to the audience, but I'd much rather sacrifice that slight aesthetic issue for reliability/durability to maintain quality.
 
“belts” may be referring to Wireless Mic Belts, dance belts, or small running belt waist pack. Simple ones can be made by sewing enabled parents. I once grabbed a dozen from an athletic store that was closing.
 
If it is the connector, it could just be dirty. Caig DeoxIT D5 first, followed by Caig Gold is the way to clean connectors. The connector could be broken inside the beltpack, too.

It could also be a broken mic cable. They tend to break close to the connector strain relief because of extra stress there. Cutting out the bad section and resoldering to the connector can save that.

If there are no bangs from manipulating the connector and cable, then the issue is RF dropouts. That could be caused by poor frequency management, which is very possible with 15 systems running, or it could be a problem with where the receive antennas are located.
 
If it is the connector, it could just be dirty. Caig DeoxIT D5 first, followed by Caig Gold is the way to clean connectors.

Just got back from the matinée. Yes, it was the connectors. Turns out, it was the connectors on the seven we rented, not any of the eight we own (And I am going to be having a serious discussion with the director about how much of our rental fee we should be getting back; this particular outfit has provided us with a number of devices that don't work as advertised. I realize that, when you rent something, you are getting used equipment. But it ought be working used equipment. This ain't.)

The connector could be broken inside the beltpack, too.

It could also be a broken mic cable. They tend to break close to the connector strain relief because of extra stress there. Cutting out the bad section and resoldering to the connector can save that.

I really appreciate the thoughtful, supportive replies I get here, like this one. This really matched what I found before the show today. What I did was take out each body-pack, get it delivering sound out of the house speakers, and then I thumped the connectors and gently tugged the wires. In every case where there was a problem, thumping the connectors produced the banging sound. If I held the connector in one position, and tugged the wires, there were no problems. I didn't have any cleaner with me (I'm going to get some of that stuff you mentioned), but jacking the connector in and out several times seemed to help a bit, maybe by scraping off some ancient oxides. Then, as planned, I found a direction that, if shoved that way firmly and held in place (with about a foot of gaffer's tape), all lines on the connector remained closed.

If there are no bangs from manipulating the connector and cable, then the issue is RF dropouts. That could be caused by poor frequency management, which is very possible with 15 systems running, or it could be a problem with where the receive antennas are located.

The model 3000's have a direct frequency read-out. Everything is at least 500kHZ apart. The model 2000's are hard-channelized, but I have confirmed we have no channel colllisions. The 3000's are all D-band and the 2000's are all I-band. All fifteen peg the meter (well, show maximum strength) on the RF side. I've set them all to 30mW, which certainly seems enough for the short, unobstructed run we've got.

We have another show tonight, but, before the last four shows that start Thursday, I'm going to push the director to let me call the rental place and raise some heck about this. They need to buy replacements for this stuff, and I think today would be a good schedule.

In fact, that said, I'd like to make an observation and ask a follow-up question. First, the observation: I'm a total noob to theater, but I've been an amateur radio and electronics hobbyist for over 40 years. I feel qualified to say that, in this application, this connector is A Piece of Junk. Now, the question: why do complete model 3000 systems cost more than my all-mode, 100w, 550kHz-440mHz, Yaesu transceiver? It's just a flippin' wireless mike, fercryinoutloud! Granted, it must have better audio performance than my Yaesu, and must deliver balanced signals out of its XLR jack. I'm willing to pay a bit more than I would for, say, a baby monitor, to get those things. But... $800? For that, I want it to be battle-ready and combat-hard, and definitely not in need of solutions requiring gaffer's tape, of all things (though I am told there are few problems in theater that can't be addressed with enough of it :) ). The tape actually did get us through the show (and, I hope, will do so again in two hours at the evening performance).

sdauditorium mentioned another model. What else do you folks suggest? We're on a limited budget (being a school), but we won't be renting this stuff again (if I have any say in it). I'd like us to buy something we can, if not pound on with a hammer, at least maintain with modest effort. Resoldering loose wires isn't too much to ask, but the connector on those 310s looks bad in ways that solder can't fix.

What should we use?
 
To be fair to Audio Technical the 3000 series can be had for 550$ +tax from any retailer in the US. They are mid range cheap consumer level wireless. They would be far from my first choice of wireless to use when I need almost 16 of them and for micing stage/actors, in musicals or plays. You are right they are not built as robust as other competitors or higher level series. They do hit a price point that public schools like however. expensive enought that they work pretty well yet cheap enough to replace outright a component gets toasted :)

As far as why they cost more then the other equipment you specified that i'm unfamiliar with. Audio quality i'm sure is key. while the AT3000 aren't built as tough as I would like they still have clear audio when used gently and appropriately much more clarity then any hand held Radio. the Mic elements themselves on the systems start minium baseline around 80$ a peice (and that for the cheaper AT/Shure base elements. Sennheiser base wireless lavs start about 124$ (already more then the handheld radio you mentioned, and all we have is a small wire with nothing to plug it into :)

Lots of folks have their preference of wireless systems. I personally Love the Sennheise EW100 (or EW300, if you need more simultaneous users, and are touring with them) they are a bit more then the AT3000, have meta beltpack housing, screw locking 1/8" connectors. they cost a little more, and their Antenna Distro is pricier as well, so the are definalty a slight step up in cost.

I'd definatly talk to your rental people and make them aware of the problems in their equipment and your dissatisfaction.


(PS- my grip with the AT3000 series i encountered at a school musical I did last February. The little slidey cover that protects the power-on/ channel set buttons is flimsy enough that kids can still accidentally mute them selves but just leaning back hard in a chair. (I think I did discover the a mute lock option in there bury deep in menus, which if it exists I highly suggest you enable :)
 
That sucks that it was the rentals but all 7 really bites a big one. I would make sure to test any and all equipment you get from them now on before they leave in case something is faulty. Although the hardest test to do is the in the moment test when an actor decides to do something like fall and throw the body pack across the theatre.

I don't think you will get much back from the rental house besides a sorry, unfortunately. Worth a try though.
 
Being local I’d like to know who stuck you with the bad gear. Please PM me, especially if they do not take care of it before Thursday.
Thanks,
Jim
 
In defense of the rental company, the units were probably checked and found to be in good working order when they were returned from the last rental. Then they were placed on the shelf in a cold, damp warehouse. The units may have been on the shelf for a considerable length of time and the connectors oxidized from the high humidity. One doesn't normally expect problems to develop in equipment that hasn't been handled, but that is precisely why they developed the problem. Switches and connectors are happiest when they get exercised.
 
In defense of the rental company, the units were probably checked and found to be in good working order when they were returned from the last rental. Then they were placed on the shelf in a cold, damp warehouse. The units may have been on the shelf for a considerable length of time and the connectors oxidized from the high humidity. One doesn't normally expect problems to develop in equipment that hasn't been handled, but that is precisely why they developed the problem. Switches and connectors are happiest when they get exercised.

That's all entirely possible, but it didn't take much use for us to find these problems (and in several of the units). The impression I am getting, also, is that this equipment actually is in high demand (we took their entire inventory of seven units, and were "lucky" to get them, as they told us a lot of other schools were asking for them).

More to the point, though (and, really, I don't mean to sound arrogant when I say this), it's not my problem. One reason we rent, rather than buy, a lot of this stuff, is that we aren't in a position to maintain it. So, we rely on the rental company to take that responsibility, even if--over the long haul--we end up paying more than it would have cost to buy our own gear. If your speculation that oxidation is the culprit is correct, then I'd see it as incumbent upon the company to give the connectors a cleaning just before delivering them to each new renter.

However, having confirmed what folks here told me to expect (that the connectors on the Audio Technica body packs are feeble), I don't blame the rental company for failing to clean or maintain them. I blame the rental company for not having returned them to Audio Technica and replaced them with better stuff. These little connectors were clearly not up to the rigors of stage use. Maybe they can take the wear and tear imposed by a museum docent or a college professor, but they have no place on the bodies of musical theater performers. Heck, even in my ham shack, I wouldn't find this robust enough for commonplace activity. I mean, when I poke them, they wobble, while fully inserted. It's as though they lack any kind of positive interlock. I was a little bit stunned to see this.

So, yeah, there are limits to what a rental place can cope with, but, really, I just think this gear is not what they should be renting in the first place.

BTW, the gaffers-tape trick we used to abate the problem for the afternoon show continued to work through the evening performance. Thanks again to the folks here who pointed me in the right direction.
 
...Maybe they can take the wear and tear imposed by ... a college professor...

As someone who works in a university AV department, I would suggest on stage use is much kinder...
Academics have no training and when you're running hundreds of mics on the campus, you can't babysit them, so yeah, we get plenty of mics back in "other than the condition they left"
They're a consumable in our context...
 
The model 3000's have a direct frequency read-out. Everything is at least 500kHZ apart. The model 2000's are hard-channelized, but I have confirmed we have no channel colllisions. The 3000's are all D-band and the 2000's are all I-band. All fifteen peg the meter (well, show maximum strength) on the RF side. I've set them all to 30mW, which certainly seems enough for the short, unobstructed run we've got.

In fact, that said, I'd like to make an observation and ask a follow-up question. First, the observation: I'm a total noob to theater, but I've been an amateur radio and electronics hobbyist for over 40 years. I feel qualified to say that, in this application, this connector is A Piece of Junk. Now, the question: why do complete model 3000 systems cost more than my all-mode, 100w, 550kHz-440mHz, Yaesu transceiver? It's just a flippin' wireless mike, fercryinoutloud! Granted, it must have better audio performance than my Yaesu, and must deliver balanced signals out of its XLR jack. I'm willing to pay a bit more than I would for, say, a baby monitor, to get those things. But... $800? For that, I want it to be battle-ready and combat-hard, and definitely not in need of solutions requiring gaffer's tape, of all things (though I am told there are few problems in theater that can't be addressed with enough of it :) ). The tape actually did get us through the show (and, I hope, will do so again in two hours at the evening performance).

While the connectors do seem to be your issue, Just because you have things spaced 500kHz apart doesn't mean you aren't stepping on yourself with intermod interference. With wireless mics you need to not only tune them out of the way of DTV stations, but also around interference from themselves and their harmonics. The more units you use, the harder a task this can become. If your wireless has an automated list of freqs built in, set them all to the same group and tune each one to a different channel in that group -- being sure to avoid the DTV stations in your area (which can be found with a quick google search).

The reason for the high cost in RF systems is due to the amount of electronics being shoved into tiny housings that need to take a lot of abuse on a very repetitive basis, run for long times off of a battery, and need high audio quality. There are a few processes that occur in the transmitter, including companding, the display readouts, and physical transmission. There is a reason pro theater spends a lot on wireless systems, audio aside - pro transmitters can be thrown at a wall, stomped on, and take moderate moisture damage and will still transmit. Plus they all sound fantastic, and exactly the same -- a unit bought 10 years ago will sound like a unit bought today if in the same product family.

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As for the rental shop, having worked in a half dozen rental shops, I have only ever seen testing of gear at the upper-tier shops. Local shops almost always rely on the person renting to flag gear as bad when it comes back. Mid tier shops might plug a unit in and make sure it passes audio and that the knobs on gear aren't too dirty, and high end shops are plugging things into automated test benches and testing for every aspect of performance, cleaning and testing every piece of cable, and fully cleaning every knob/button/fader on everything. Local shops almost always end up charging a lot more too because they don't have the economy of scale.
 
We recently rented 10 AT units for a show a month or so back (I don't remember the exact model) and had the exact same problem as you. I came to the conclusion that the connectors were bad, as any moderate jolt was enough to make them pop. There wasn't much we could do, as we only had 4 other lav packs that I threw on the most important principles. It was a rough show...

Sent from my m8wl using Tapatalk
 
While the connectors do seem to be your issue, Just because you have things spaced 500kHz apart doesn't mean you aren't stepping on yourself with intermod interference. With wireless mics you need to not only tune them out of the way of DTV stations, but also around interference from themselves and their harmonics.

While I'm a theater noobie, radio is something I do have experience with. I didn't previously mention it, but one of the rental units was set to an in-use frequency when it arrived. I changed it. Electronically, I'm quite satisfied with the AT equipment. Electrically, however, that connector is a show-stopper. (Hey, I just used that idiom literally, for the first time!)

There is a reason pro theater spends a lot on wireless systems, audio aside - pro transmitters can be thrown at a wall, stomped on, and take moderate moisture damage and will still transmit.

For what we paid to get these things, I would have expected your description to apply. Again, though, I don't really blame the rental place for how fragile the connector is: I blame Audio Technica. The lesson here is not to avoid this rental place (we were able to cope with all of the other issues ourselves, pretty easily). I think the lesson is to avoid renting the 210 or 310 body-packs.
 

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