Dante Help

[The JC]

Context: I’m in a theatre which has a show relay (Supplied via mics above stage) that is sent around the backstage areas. The Comms rack which houses all equipment for this has recently been stripped out because it was close to a spaghetti fire hazard and had redundant equipment which had been unplugged but not removed over the years. The relay is controlled via Dante on a Symetrix 12x8 Radius which sends to 12 wall panels around the building. The wall panels are capable of 6 channels, although we only use one.

 

Issue: Only 1 of the 12 panels has power to it, and although it’s connected the “Arc” light on the front of the Symetrix isn’t on. I assume this is how it sends power to the panels? It is only that panel with power that has a working feed. The venue also has a tonne of cables which are unlabelled and go in and out of untraceable trunking which doesn’t help.

 

Question: Can someone explain the basic principle of how the system SHOULD work (In fairly simple terms!) and the way things should be cabled? That way I can apply it to this venue and it’s unique characteristics.Also any help on why my Arc system isn’t on would be appreciated. It’s wired into the back of an unlabelled CAT5 patch panel.

 

Cheers everyone!

[gyro_gearloose]

Does any part of the system actually work as expected? If the Arc light is off then one would assume that the wall panels, which communicate and are powered via the Arc port, won’t work, but you are saying one panel does work? If the rest of the wall panels don’t work then I’d suspect a cabling fault between the first working panel and rest of the panels. If the system doesn’t work at all then the Symetrix master unit may have lost its programming.

 

I’m not sure why you’ve got a Dante equipped DSP unit just to handle distribution of your show relay. Seems like overkill to me, or people don’t know how powerful that system can be. A quick look at the Symetrix Radius spec. sheet suggests that your show relay mics would plug into the Radius’ analogue inputs, the signal to each speakers amplifier would come out of the analogue outputs, and the wall panels would be daisy chained together from the Arc port.

 

Be careful with the Arc cabling. It contains 24VDC which might not play well with anything else that also uses CAT5, like IP phones, computers, etc. Remember, CAT5 is just a cabling standard which says nothing about what those cables are actually used for.

[mnorwood]

Hi there! I also work at a venue with a Symetrix, although we run FOH audio through it.

 

Firstly, unless I'm misunderstanding how your system is setup, Arc has little to do with your problem. "Arc" is Symetrix's way of remotely controlling the routing and volume of audio as it passes through the main Symetrix device(s). Whilst it does have the ability to carry audio and power, the audio is not Dante and the power is 24vdc. Unless your panels look like those found here: http://www.symetrix.co/products/arc-wall-panels/, Arc has nothing to do with your problem. (And as gyro points out: Arc and Ethernet/Dante - although running over the same type of cable - are not electrically compatible and should never be cross-connected.)

 

Whilst it is possible to get a Dante-enabled wall-panel that can be powered via PoE (Power over Ethernet, ~48vdc), the power will need to be injected somewhere down the line: AFAIK no Symetrix device will provide power via its Dante ports. It is thus more likely that either the panels are self-powered, or a PoE injector is needed somewhere in your networking infrastructure.

 

I'd recommend learning more about where the cables are running. You don't specify whether the cabling you're using has been "borrowed" from IT, or had been run specifically for the theatre (even if it's been re-purposed from its original intent). If the former, perhaps your local IT team has documentation about where cables run. If the latter, perhaps whoever ran the cable kept records.

 

I think to give any more advice, we'd have to know more about the system you have. What are the wall panels you have (make/model)? Is the Symetrix intended to replace functionality previously provided by the "comms rack"? How is the back of the Symetrix cabled up?

 

And yes, using a Symetrix device for show-relay is overkill.

[The JC]

Thanks for the replies! I’m relatively new to the venue and have been given 0 handover notes so it’s a bit of a voyage of discovery for me.

 

I have since discovered that the system is as follows:

 

- We have Australian Monitor DigiPage. These eventually end up at the same speakers that the show relay comes through. The wall panels are also Australian Monitor and have 6 zone selectors; the tannoy “ducks” whichever channel your on when it is used.

 

- The Symetrix system is linked to the DigiPage system by CAT5 - It appears to be via the cable which splits out to the Arc port too. The Arc light now flashes very very intermittently (Whereas before there was nothing). I now also have a constant green light on Input A1 (Again, beforehand there was nothing).

 

- The Symetrix xOut 12 is still showing just one channel as working; the wall panel has power but no audio. It seems to be that we made progress in one area and have lost it in another.

 

Thanks for all your help so far.

[mnorwood]

Well that just raises more questions.

 

The User Manual of the Digipage (available here), is adamant than none of its cat-5 connectors are compatible with Ethernet (which also rules out Dante) and, from the pin-outs provided, are also not compatible with Arc. So connecting the Symetrix with the Digipage via Cat-5 cable is liable to cause damage to one or both units.

 

The "Arc" indicator on the Radius 12x8, when a compatible device is connected, turns solid green. The intermittent flickering could be an indication that the Symetrix is unsure of what's plugged in.

 

The "Input A1" is (fairly obviously, I'll admit) the status indicator for Analogue Input 1. As with the LEDs for all the input and output indicators on the front, the LED gets brighter the hotter the signal, until it exceeds a threshold (not sure what, possibly +3dB) at which point it turns yellow (until the signal falls below the threshold again). If it turns Red, the signal's clipping. A constant unwavering green glow would indicate an incoming signal at a constant volume. Not quite what I'd expect from a show relay mic.

 

I don't believe you've mentioned the Symetrix xOut 12 before. How is this connected into the rest of the system?

 

You haven't mentioned your position within the theatre (are you in-house technical? visiting?), nor how much authority you have to be making cable/routing changes (don't want to be suggesting things, only to get you yelled at by your boss/management). It does seem a little odd that a "Major theatre in London" (to quote from your user profile) has what appears to be an entirely undocumented system.

 

And it's still unclear as to what relation the old comms rack had. Was this all previously mounted in that and was unplugged so the rack could be removed, and you/your colleagues forgot to label cables before unplugging them? Or is this a new system to replace what was in the rack to begin with?

 

Is it perhaps possible to put together a diagram of how you think things are currently connected (with question marks next to connections you're unsure about)?

Edited October 28, 2019 by mnorwood