Cross Compatibility of Comms Systems.

[jon-hill_uk]

Obviously I know theres some level of interconnectivity on comms systems, Most of the 2 wire systems out there share the exact same system, even down to accessories(Headsets and the like) but which will connect into what, and what changes need to be done.

 

so far,

Tecpro will connect into ASL, and vice versa.

 

but what about

ROH into Telex RTS, telex RTS into ASL, etc.

 

whats gonna link in and what fiddling needs to be done?

 

I'm currently looking for more belt packs(yeah, everyone is) and need to spend as little as possible as this is a non-profit org which can't stand too much extra outlay.

 

currently we use tecpro's with BP111 and 1 BP117 needing to expand by 2 beltpacks and seen some ROH ones, will they work, etc?

 

if anyone knows or has seen these in action, please let me know.

 

regards,

Jon

[peternewman]

I don't know of the ROH ones, but ASL should be compatible with Tecpro (although I don't think I've personally ever used them together), anyway the ASL ones are very cheap compared to Tecpro, especially the plastic one they do, try 10 out of 10 or Thomann for prices. They also do a selection of headsets for them, from budget to higher quality similar to Tecpro single and double muff.

[gareth]

I'm not 100% sure of this, it's off the top of my head and I'd need to check to be certain, but as far as I know ASL and Tecpro are compatible ; and Clearcom, RTS and Telex are compatible. But there's no intercompatibility between the two groups.

 

As I said, though, don't take that as gospel - it's a half-remembered 'fact' from the dark recesses of my memory! If anyone knows better, please corect me!

[mackerr]

I'm not 100% sure of this, it's off the top of my head and I'd need to check to be certain, but as far as I know ASL and Tecpro are compatible ; and Clearcom, RTS and Telex are compatible. But there's no intercompatibility between the two groups.

 

As I said, though, don't take that as gospel - it's a half-remembered 'fact' from the dark recesses of my memory! If anyone knows better, please corect me!

AFAIK ASL, Tecpro, and Clear Com are compatible, RTS is a different system, and Telex Audiocom is another different system. ASL, Techpro, and Clear Com are single channel with unbalanced audio on pin 3, and power on pin 2. RTS is also unbalanced, with ch 1 on pin 2 and ch 2 on pin 3, power can be either channel depending on how the system is set up. Telex Audiocom is balanced audio on pins 2 and 3, with power on pin 2. There are commercial intefaces to combine systems such as the Clear Com TW12B. There is a lot of information about intercom and how to interface and adapt different systems at Pete Erskine's download page here.

 

Mac

[boatman]

To add one more to the list; Stonewood Audio's CBP1 is fully compatible with Tecpro BP111. I haven't used SAs dual channel or high power belt packs, so I can't comment on them.

[cedd]

Another to throw into the pot.

 

Stonewood audio used to be Metro Audio, so their units are cross compatible (same boxes, different labels from what I can tell).

[dbuckley]

As far as I've seen, most of the party line systems feature "ClearCom compatibility", inc ClearCom PL, TechPro, Production Intercom, ASL, StoneWood, Telex ClearCom party line compatible; these are all compatible-ish, in that you can usually connect together a small system of these units and they will work perfectly happily together.

 

As the size of system goes up then it can all become unglued, ending up with the system becoming unstable, resulting in feedback. Adjusting sidetone rejection can help.

 

Mac Kerr covers how RTS and the native Telex systems differ (note Telex now own RTS, so there are vintage differences); they are still audio bus systems, but with differing power arrangements and differing impedance; if my memory serves they are current modulated rather than voltage.

 

Also differing is how calling is handled; the ClearCom standard is a positive voltage (+12 or greater, I think) on the audio wire. Others use ultrasonic "audio". Some really weird stuff is out there, like Leon sending 300 baud data over audio at 39KHz.

 

Other intercoms are "four wire"; almost all TV, and most of the "matrix" intercom systems are analogue four wire. These systems have a balanced pair each for TX and RX, hence, "four wire". They need a central matrix control box, and the various brands are incompatible with all the others as they have digital switching. So don't buy these from eBay unless you know exactly what you are getting yourself into ;)

 

The OP is advised to stick to simple PL kit, transverting to other systems increases hassle and cost.

[obsoperator]

The OP is advised to stick to simple PL kit, transverting to other systems increases hassle and cost.

Amen. In particular, no matter how much money you spend on RTS-to-Clearcom interfaces, OEM or homebrew, you will have level, noise, and "Call" voltage problems. I am reminded that when a TV shoot came into my live theaters, there was at least one, and sometimes two people who spent every call, 100% of their time, on intercom. To them - perhaps appropriately - the show was "all about PL". They weren't interested in the brand of PA, the famous singers who'd appear, or the choice of light board. But how many of us have the luxury of working full-time on intercom all day, day after day? Keep it simple. You haven't saved any money if the composite system works poorly. I can tell you, I got pretty tired of being unable to hear the lighting designer in the truck properly!

[mackerr]

I am reminded that when a TV shoot came into my live theaters, there was at least one, and sometimes two people who spent every call, 100% of their time, on intercom. To them - perhaps appropriately - the show was "all about PL". They weren't interested in the brand of PA, the famous singers who'd appear, or the choice of light board. But how many of us have the luxury of working full-time on intercom all day, day after day?

I've been that guy. ;) I agree that the OP should stay away from non-compatible systems. It is pretty easy to interface them, but may cost more than he wants to spend on the whole system. There should be no real problems mixing Clear Com, Production Intercom, Techpro, or any of the other compatibles. Telex or RTS should be avoided in this case unless they are the whole system.

 

Mac

[Martin]

To add one more to the list; Stonewood Audio's CBP1 is fully compatible with Tecpro BP111. I haven't used SAs dual channel or high power belt packs, so I can't comment on them.

 

In theory the dual channel packs of the above should work together electrically but the pinout of the 6pin XLR's is different:

 

Techpro use pin 1-Screen/Ground, 2-Power, 3-Audio A, 4-Audio B.

Stonewood/Metro use pin 1-Screen/Ground A, 2-Power A, 3-Audio A, 4-Screen/Ground B, 5-Power B, 6-Audio B

 

So adaptors could be made, but it's easier to keep them separate. As Boatman says, the single channel packs are fine together, as are the ASL single channel packs, but I have had trouble using the cheap ASL headsets with Stonewood packs.

[J Pearce]

Just to add, on a show I worked on recently we had one clearcom pack in an otherwise exclusively Techpro rig, and the clearcom unit seemed an awful lot louder than the techpro units.

[mackerr]

Just to add, on a show I worked on recently we had one clearcom pack in an otherwise exclusively Techpro rig, and the clearcom unit seemed an awful lot louder than the techpro units.

Was the CC pack louder talking to the rest of the system, or was the listen of the CC louder than the other packs? There may be a difference in operating level between the systems, or the CC may just have a headphone amp with more output.

 

Mac

[Mr Steve]

Incase it helps, we've used Tecpro belts and heads with Stonewood belts, and ASL headsets in various configurations and it works fine. All single channel though.

[J Pearce]

The CC pack's mic was deafening to everyone else on the ring. The headphone volume on the pack itself was fine.

 

I suspect they operate on different impedances.

[mackerr]

The CC pack's mic was deafening to everyone else on the ring. The headphone volume on the pack itself was fine.

I suspect they operate on different impedances.

If it is a Clear Com 501 belt pack there is a switch to change the mic level. It is recessed on the bottom of the pack, and may be labeled H - L, or maybe Dyn-Elect. If it is the older chrome steel RS100 or even older blue RS100, there is nothing that can be done easily. I would expect the system impedance to be the same, most comm systems are terminated by the power supply at about 200 ohms. Some older CC power supplies have a 200-400 switch so you can use 2 parallel power supplies by increasing the termination to 400 ohms each. The plastic CC packs have a much higher load impedance than the older metal ones, so you can put many more of them on a ring.

 

Mac