FOH / MONS / STAGE dedicated comms system/mixer project

[fedorterrell]

Hi to all of you !

 

I'm Piotr, I'm located in France and I'm sound engineering mostly in live music.

 

I'm very often puzzled by some of the difficulties of an easy communication in our working environnement between the different locations. There are different solutions used, depending on the company, the festival and so on... mostly via small dedicated mixers, and two input powered speakers (https://www.behringer.com/Categories/Behringer/Loudspeaker-Systems/Portable/B205D/p/P0957#googtrans(en|en) for example).

 

Maybe this is sufficient, maybe not, maybe there's a simpler way especially concerning the routing, inputing and outputting of utility signals as TALK mics etc... and sharing/providing them to incoming productions.

 

So I've started a project, based on the usual setups on concert and festival stages, and discussions with my fellow colleagues in France and Switzerland, that intends to simplify the routing and mixing of the various sources needed: FOH talk, MONS talk, FOH shout, MONS shout, STAGE wireless talk, STAGE IEMs...

Basically the idea is to have two 19" racks, one at FOH, one at MONS, that are dedicated mixes (5 sound sources to 3 mix busses), with 4 analog lines running (either/or XLR and CAT5 analog as in the RATCAT family http://soundtools.com/products/catfamily.php).

 

I have a basic knowledge of electronics, I have successfully built a lot of projects (9K preamps, 1176, 51x 500 racks...), I'm learning KiCAD...

 

At this point I need help !!! I'm not an electronics designer so there's a lot of things I need to clarify.

 

The project calls for "basic blocks": MIC/LINE preamps (no 48v), MIC Splitting (easiest probably done with transformers ?), LINE Receivers to LINE OUTPUT, SUMMING stage (with mutes and level control probably) and LINE OUTPUT stage.

 

I've investigated a simple INA217 based preamp as for example in:

 

http://plchambert.ca...9/33836333.html

 

https://www.diyaudio...-templates.html

 

I've investigated basic mixer topologies as for example in:

 

https://sound-au.com...udio-mixing.htm

 

https://www.electro-...circuit.122073/

 

I'm trying to figure out which way to go and design then build this project, so before going further I'm hoping for some general wisdom !!!

 

I clearly need a method to put it all together, so I would happily read your comments as to the steps you think I need to follow: general idea > basic synoptic > schematic > PCB design...

 

I need to narrow down the building blocks to simple and easy to implement solutions: which MIC/LINE preamp, which SUMMING solution etc...

 

And of course what are the bad ideas I need to throw away !!!

 

As to clarify the general intention, here is a basic synoptic, which omits the local details of the racks (input connectivity and switching).

 

The FOH rack is basically a passive input/output "patching" box, no mixing necessary, just connectivity.

The MONS rack is where the mixing/summing/routing takes place so I guess active is the only solution.

 

There are basically four different situations that need to be dealt with:

 

Situation A : FOH with House desk / MONS with House desk

 

Situation B : FOH with Production desk / MONS with House desk

 

Situation C : FOH with House desk / MONS with Production desk

 

Situation D : FOH with Production desk / MONS with Production desk (where the house communication system is generally not used but remains in use for the other shows.)

 

That's it for the opening post !!!

 

Tell me what you think. Tell me what to clarify.

Looking forward to your insight and ideas,

 

Thanks in advance !!!

Regards,

 

Piotr.

 

 

https://www.icloud.com/iclouddrive/0oJRyb8MiqDE4rgSyom5BVOhg#FOH_MONS_Comms_General_Principle

Edited July 31, 2019 by fedorterrell

[sameness]

mostly via small dedicated mixers, and two input powered speakers

 

Standard for FOH and monitors to communicate quickly.

 

As for the rest...why not utilise a standard coms system? Clearcom, Greengo, Riedel etc?

[fedorterrell]

mostly via small dedicated mixers, and two input powered speakers

 

Standard for FOH and monitors to communicate quickly.

 

As for the rest...why not utilise a standard coms system? Clearcom, Greengo, Riedel etc?

 

Hi !

 

Thanks for your answer.

 

Well, Intercom systems are great outside of the utility comms on stage, they are of not use for the audio comms during setup, line check, soundcheck. They're here mainly for the overall management of an event, stage management etc...

 

On the other side we're talking audio signal, mixed and routed through the desks and utility speakers.

For example a TALK mic sent from FOH (either from the house or the guest desk) needs to be routed to several destinations: the MONS console (that will distribute it on stage and IEMs), the MONS COMMS speaker, the stage crew IEMs and possibly other destinations. When you guest a console and you're often asked to interface it with the house COMMS, while other desks may be connected differently...at the same time.

 

Lately I spent 3 weeks at the Montreux Jazz Festival and over 16 days and 50 bands we had the pleasure of greeting, there were a lot of different situations that I've tried to summarize with the 4 situations thing for example. Every day different !

 

The whole thing is to try to make this process as simple as possible, with a dedicated tool, and believe me it seldom is simple for a lot of reasons.

 

Thanks, regards,

 

Piotr.

[sunray]

mostly via small dedicated mixers, and two input powered speakers

 

Standard for FOH and monitors to communicate quickly.

 

As for the rest...why not utilise a standard coms system? Clearcom, Greengo, Riedel etc?

 

Hi !

 

Thanks for your answer.

 

Well, Intercom systems are great outside of the utility comms on stage, they are of not use for the audio comms during setup, line check, soundcheck. They're here mainly for the overall management of an event, stage management etc...

 

On the other side we're talking audio signal, mixed and routed through the desks and utility speakers.

For example a TALK mic sent from FOH (either from the house or the guest desk) needs to be routed to several destinations: the MONS console (that will distribute it on stage and IEMs), the MONS COMMS speaker, the stage crew IEMs and possibly other destinations. When you guest a console and you're often asked to interface it with the house COMMS, while other desks may be connected differently...at the same time.

 

Lately I spent 3 weeks at the Montreux Jazz Festival and over 16 days and 50 bands we had the pleasure of greeting, there were a lot of different situations that I've tried to summarize with the 4 situations thing for example. Every day different !

 

The whole thing is to try to make this process as simple as possible, with a dedicated tool, and believe me it seldom is simple for a lot of reasons.

 

Thanks, regards,

 

Piotr.

 

If I understand correctly you are trying to route a microphone to preselected outpus.

And then to do this with several microphones, each to their own selected outputs.

If this is to be a fairly standard setup without too much change on different events I'd consider something like this: https://www.ebay.co....ZbLVGlBasically a 12x12 matrix (8 mic + 4 line level) and additionally there are 2 channels of echo cancelling which may be an advantage for a mic in a noisy location.

Additionally a pair (or more) can be linked using an RJ 45 cable (Cat 5), ie FOH and on stage.

Designed for audio conferencing work but I've used them to link multiple PA systems on complex jobs and radio studios together and to the transmitter and phone lines.

I think I may have an AP400 here still (8x8 matrix = 4mic+4line level plus telco and one echo cancel) and possibly an XAP800.

[Brian]

The project calls for "basic blocks": MIC/LINE preamps (no 48v), MIC Splitting (easiest probably done with transformers ?), LINE Receivers to LINE OUTPUT, SUMMING stage (with mutes and level control probably) and LINE OUTPUT stage.

 

Many years ago Canford Audio used to sell a range of ready-made PCBs, each of which did exactly the functions you have identified. I used them to make custom-made commentators units for sports broadcasting.

 

They no longer seem to do them but instead now have a range of modules which do it...

 

https://www.canford.co.uk/RDL-AV-INTERFACES-STICK-ON-Series

 

They are small enough to fit inside a 1U rack, being only 38mm high.

[sunray]

The project calls for "basic blocks": MIC/LINE preamps (no 48v), MIC Splitting (easiest probably done with transformers ?), LINE Receivers to LINE OUTPUT, SUMMING stage (with mutes and level control probably) and LINE OUTPUT stage.

 

Many years ago Canford Audio used to sell a range of ready-made PCBs, each of which did exactly the functions you have identified. I used them to make custom-made commentators units for sports broadcasting.

 

They no longer seem to do them but instead now have a range of modules which do it...

 

https://www.canford....STICK-ON-Series

 

They are small enough to fit inside a 1U rack, being only 38mm high.

Again, I MAY have some of these devices floating around, I used to use a lot of them and tended to to revamp systems quite often and had a box of random units. I haven't dipped into it for a while.

They are about 80x38x20mm from memory and come with a heavier duty version of velcro and we often mounted them in the sides of 19" racks, on the side of runners etc.

 

There is a very useful 2U rack unit made which holds them vertical too which is only about 75mm deep and often fits behind other units.

Edited August 2, 2019 by sunray

[fedorterrell]

mostly via small dedicated mixers, and two input powered speakers

 

Standard for FOH and monitors to communicate quickly.

 

As for the rest...why not utilise a standard coms system? Clearcom, Greengo, Riedel etc?

 

Hi !

 

Thanks for your answer.

 

Well, Intercom systems are great outside of the utility comms on stage, they are of not use for the audio comms during setup, line check, soundcheck. They're here mainly for the overall management of an event, stage management etc...

 

On the other side we're talking audio signal, mixed and routed through the desks and utility speakers.

For example a TALK mic sent from FOH (either from the house or the guest desk) needs to be routed to several destinations: the MONS console (that will distribute it on stage and IEMs), the MONS COMMS speaker, the stage crew IEMs and possibly other destinations. When you guest a console and you're often asked to interface it with the house COMMS, while other desks may be connected differently...at the same time.

 

Lately I spent 3 weeks at the Montreux Jazz Festival and over 16 days and 50 bands we had the pleasure of greeting, there were a lot of different situations that I've tried to summarize with the 4 situations thing for example. Every day different !

 

The whole thing is to try to make this process as simple as possible, with a dedicated tool, and believe me it seldom is simple for a lot of reasons.

 

Thanks, regards,

 

Piotr.

 

If I understand correctly you are trying to route a microphone to preselected outpus.

And then to do this with several microphones, each to their own selected outputs.

If this is to be a fairly standard setup without too much change on different events I'd consider something like this: https://www.ebay.co....ZbLVGlBasically a 12x12 matrix (8 mic + 4 line level) and additionally there are 2 channels of echo cancelling which may be an advantage for a mic in a noisy location.

Additionally a pair (or more) can be linked using an RJ 45 cable (Cat 5), ie FOH and on stage.

Designed for audio conferencing work but I've used them to link multiple PA systems on complex jobs and radio studios together and to the transmitter and phone lines.

I think I may have an AP400 here still (8x8 matrix = 4mic+4line level plus telco and one echo cancel) and possibly an XAP800.

 

Hi !

 

Thanks for your answer and link ! I will definitely give it a look.

 

Yes, the thing is about easy routing and summing of a couple sources (Mic and line).

 

Thanks !

 

Piotr

 

The project calls for "basic blocks": MIC/LINE preamps (no 48v), MIC Splitting (easiest probably done with transformers ?), LINE Receivers to LINE OUTPUT, SUMMING stage (with mutes and level control probably) and LINE OUTPUT stage.

 

Many years ago Canford Audio used to sell a range of ready-made PCBs, each of which did exactly the functions you have identified. I used them to make custom-made commentators units for sports broadcasting.

 

They no longer seem to do them but instead now have a range of modules which do it...

 

https://www.canford....STICK-ON-Series

 

They are small enough to fit inside a 1U rack, being only 38mm high.

Again, I MAY have some of these devices floating around, I used to use a lot of them and tended to to revamp systems quite often and had a box of random units. I haven't dipped into it for a while.

They are about 80x38x20mm from memory and come with a heavier duty version of velcro and we often mounted them in the sides of 19" racks, on the side of runners etc.

 

There is a very useful 2U rack unit made which holds them vertical too which is only about 75mm deep and often fits behind other units.

 

Hi !

 

Thanks for your link and input. I was not aware of the Canford units, they seem like a great idea !

I'll browse through it !!!

 

Thanks !

 

Piotr.

[sunray]

My concern with these units is the cost, at more than £100 plus VAT each a fairly small project can easily reach £1000.

[fedorterrell]

Hi !

 

that's certainly not possible for a project like mine cost wise...but the modular/building block approach is probably the best way to design the project !!!

It's a cool idea to build a rack with small pcbs with various tasks (mic/line input, summing, output stage....).

 

I'll investigate this !!!

 

Thanks,

 

Piotr.

[Brian]

You might be able to do it with bits from eBay. For example...

 

Dual unbalanced to balanced converter PCB.

 

Mic pre-amp PCB