Budget Com System- Best Beltpack option?

manuallyfocused

Active Member
I'm putting together a quick and dirty low-budget com system for our auditorium, and have what I think is a decent plan but with a couple of holes. We have no installed com (up to now we've used 2-way radios), but we do have a 16-channel analog audio snake that runs from the booth to backstage right (this is not used during most events as we use a digital snake now).

We need to serve a total of 4 users normally, and integrate with a wireless system that we will rent once a year for our musical production.

For normal use:
-Main station in the booth with a headset
-SR ASM (directly fed from one of the channels in the audio snake)
-SL ASM
-SL A2

For the musical:
-Main station in the booth for SM/LBO/Proj.
-House Left spot op (channel 2)
-House Right spot op (channel 2)
-FOH Audio directly fed from the main station (likely on channel 1)
-Rented Clearcom BS410 or BS210 Wireless base station backstage (fed from channel 1 through the audio snake)
-Wireless beltpacks for SR and SL ASM, A2, and House Management

Question- if I gave FOH audio a 2-channel pack, would it be possible to put them on channel 1 from the main station and connect them to channel 2 on the wireless base station (without connecting the wireless station to channel 2 from the main station)? Then I could use channel 2 on the wireless for communication between FOH audio and backstage A2. Would this require a separate power supply?

My equipment purchase plan thus far is as follows:

Telex MS2002 main station- already purchased used off of ebay

4 Pro Intercom MH310 headsets

3 single-channel beltpacks (plus 1 2-channel pack if the answer to my question above is yes)- this is where I'm not sure. I could go for Telex, Clearcom, or Pro Intercom. Is there any real advantage to going one way or another with this? The cost difference between used and new here isn't enough to make it worthwhile to go used, so it's between new Telex BP4000s, Clearcom RS701s, or Pro Intercom BP1s. The main station appears to be able to support any of them, and I believe the Pro Intercom headsets can work on all three. Am I correct in this? Which one should we get?

Would there be any issues running the mic cable for com alongside a run of DMX? Power cable? Unshielded CAT6?

Thanks, as always, for your help!
 
I'm sure there a lots of people who deal with these more than I do, but this has been my experience . . .

While Telex and Clearcom both use mic cable, there is a subtle difference in how they do it and there are compatibility issues when mixing gear. Some equipment is 'auto sensing' and adapts and some does not. I think it's an easy fix, but be prepared for a possible issue when you bring in the rented unit or use one brand of base station with a different brand of beltpack.

Each channel on an intercom system is a separate run of mic cable so yes you should be able to route channel 1 from the base station to channel 2 on the rented wireless unit, but if you're going straight from a 2 channel beltpack which uses only one cable (a 6 pin XLR) you'll have to rig up some kind of breakout to get two separate 3 pin connectors (and don't forget the compatibility issue). A two channel cable uses 6 pin XLR and there are two 'patterns' on 6 pin XLR, the common one 'everyone' uses and the Switchcraft pattern which is fairly obscure. The only equipment I've run into that uses the Switchcraft pattern are ETC's wired Remote Focus Units. Just keep an eye out to make sure you get the right version, the only difference is where the groove/slot that aligns them is, the pin pattern is the same. In a pinch you can take off the collar and they will mate up.

On the occasions where I've run intercom down a snake I've never had a problem with it affecting the mics in the snake. Don't think there would be any issue with running it alongside a DMX or Cat 6 cable.

We grappled with the what to do for intercom and in the end got some good radios with headsets. I'm not talking about those tiny little things you can buy at Wally World or the drug store that do musical beeps after each transmission, these were commercial grade Motorola's that used the no license required frequencies. They were an SP10 model which they don't make anymore, but there are new versions available. We went that route after considering all the costs involved. The radios ran around $225 each and lightweight headsets from ebay were cheap, a beltpack alone is over $300. One of our schools had a Telex system and while it worked great, with High School kids they were always breaking cables and mishandling the beltpacks. They killed the mic in one of the headsets and the replacement element was close to $100. Our ebay headsets for the radios were maybe $15, I won't cry if they break one. The flexibility of having everyone wireless is great and we're not depending on a base station which may go down. Plus we can move everything from one school to another or use them at the stadiums for graduation with ease. Our radios have been doing 30 to 40 performances a year for 5 years and we haven't had a problem yet, other than having to replace the rechargeable batteries this year ($8 a radio).
 
-Wireless beltpacks for SR and SL ASM, A2, and House Management

I don't mean to be that guy...but it's really odd to put an A2 on wireless com on most shows. You mentioned you had been using radios before -- a radio between the A1 and A2 works well. Additionally, House Management on show intercom is a little strange. I'd give them a radio on a channel with the SM to hand off the house.

Question- if I gave FOH audio a 2-channel pack, would it be possible to put them on channel 1 from the main station and connect them to channel 2 on the wireless base station (without connecting the wireless station to channel 2 from the main station)? Then I could use channel 2 on the wireless for communication between FOH audio and backstage A2. Would this require a separate power supply?

So from the start, you should always try to avoid deriving com from two sources. This is just a bad idea. I don't know of a way to do actually do this with RTS, I just don't have enough practical hands on experience with the gear -- If I had to take a guess, I bet an XLR M-FF "Y", with a side of the Y getting Pin 1/2 (A) and the other side getting Pin 1/3 (B) might work? But again, I don't know nearly enough about RTS to know if this would work. Pin 2 gets the Power + Audio and Pin 3 is just audio. Sharing ground might be funny, but I'm not overthinking this too much.

On Clearcom, doing this is relatively straightforward, you just can't power the Beltpacks from two different sources without it sounding funky. You have your 6-Pin to 2x 3-Pin break-in. Channel A plugs in as normal, but now you need to drop power from Channel B so throw a Pin-2 Drop on it. This is probably a place you'd actually want to use a Clearcom MT-701 Isolation Box in lieu of my suggestion, but it'll get you working. Newer gear can get power from different sources assuming the sources are the right ones, it's complicated. Best practice is to isolate the line.

I believe the Pro Intercom headsets can work on all three. Am I correct in this? Which one should we get?

Would there be any issues running the mic cable for com alongside a run of DMX? Power cable? Unshielded CAT6?

This is correct, assuming the Telex Beltpacks you buy have a 4-pin headset port and not a 5-pin headset port. As for which Beltpacks you should get, you already got Telex I'd just buy within the ecosystem. You will most likely be fine running your mic cable alongside of all of that. Your com system is inherently unbalanced, and you do run into cross-talk issues on longer runs but generally it's fine. I'm running 8 channels of com in a drive snake that's bundled with all of the things you are worried about on my current rig and problems caused by the snake run are the least of our worries with the com system.
 
I did end up getting Telex packs, all with 4-pin headset plugs. We got two BP4000 single channel packs, and 1 BP2002 two-channel pack. The BP2002 has 6-pin XLR in, and I understand that I can get 6-pin to 2x 3-pin adapters to split the channels (or build my own). Could I not plug one line from the main station into one of the 3-pin XLRs, and one line from the wireless station into the other?
 
We've been using radios of one kind or another for at least 10 years so I may be out of touch with what's out there now, but back when I was working with them Telex and Clearcom had different pin outs and one was balanced while the other was unbalanced. If they're putting compatibility switches on them, then it sounds like it's been addressed. I've heard that some Telex beltpacks have an internal jumper that can be set.
 
FWIW, the musicals I've worked on always had A2 and House manager on com.
They didn't talk often, but because Audio was usually in the house and unable to communicate with anyone by any means, and the A1 was mixing, the A2 would be able to coordinate starting the show and relay any potential issues to the rest of the team.
Same for house manager. We would coordinate closing doors based on how start of show was going or if we were waiting for the harp player to finish warming up or a last minute cosutme repair. And at intermission we'd wait until the line at the bar settled down before starting act 2
 
We definitely don't have a bar, since we're a high school :). I got the Telex folks on the phone today and they nixed my plan because the Clearcom stations don't have a power supply for their com lines, they just plug into existing lines. Oh well. The new plan is to have everybody but audio on channel 1, and audio on channel 2. Thanks for all of your assistance!
 
or take out a clean sheet of paper, spend 70 bucks, and try out my raspberry pi “picomm” system details here on another thread. Software image is free. Year or more in and multiple shows and would not go back to radios .. comm on the cheap. lots of wired and wireless ways to connect, even an app on your cell phone and earbuds in a pinch full duplex, 1 channel only, about 1 second or less of latency. we use nice logitech dect wireless headsets, and can wander far and wide in the facility.
 

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