Audio Speaker Relay?

Hi all,

Does anybody know a product that can drop straight into a C-Bus network to allow control of audio passthough for up to 4 pairs?

Cheers
Greg...

 

I assume you just want to switch audio lines on/off (please let me know if I'm wrong!).

To do this, you could just use the voltage free contacts on C-Bus relays for switching audio lines. If you don't like the idea of running an audio signal through a C-Bus unit, there are the C-Bus relay driver products which have the actual relay unit separate from the C-bus circuitry. These things are designed for bigger electrical conductors / higher currents - so the big screw terminals and relay contacts are probably great for audio!

Another method would be to use a non-C-Bus switching unit with IR control, and use C-Bus to control it via IR. This is starting to get more intricate and expensive though...

 

Like your idea Peter of using the relay driver but I suspect that the standard C-bus relays are designed more for mains switching and may not have a sufficiently low resistance material as contacts to allow reliable noise free operation at low voltage and current. I believe that for speaker cable switching the contacts are often of the relativly soft Gold (which would be blown to the winds by switching mains) they also tend to have a 'wiping' action to help clear any dirt, dust etc off the contact surface. Whether this type of contact is available in a form that the C-bus relay driver (L5504RDP) can pulse on and off is doubtful. If the standard relay contacts are acceptable (as far as contact resistance is concerned) then the other factor to concider is electrical seperation not only for interference reasons but also for electrical safety. This is why the remote driving of relays would be better than using the standard relay that would bring the audio cable into close proximity to mains wiring and probably transgresses any number of wiring regulations

 

Gents

The contacts of the C-Bus relay units aren't going to give you the requred isolation you need to switch low-voltage stuff like audio. The same contacts that can handle in-rush currents of hundreds of amps aren't as good when it comes to small signals like audio!

You'd be much better off getting some relays that are dedicated for switching audio. If these aren't suitable for driving from the L5504RDP the you might like to try hooking up the contacts of the Audio relay to a standard DIN (or otherwise) C-Bus relay unit, using the C-Bus relay as a driver, doing it "contactor style".

 

In light of this advice, I definitely agree with Newman's suggestion - using dedicated audio relays driven by a standard C-Bus relay unit. This would require installation of a separate power supply for the audio relay coils.

So Greg, it seems that the answer to your question is no - there is not a single product that can be dropped straight in if quality audio transmission is a concern. And going by your user name, I'm guessing you work with Bang & Olufsen systems... definitely no room for second-rate audio signals there!

 

Thanks to everybody for their comments and suggestions, at least I can rule out a quick and easy C-Bus solution! (maybe one for Clipsal in the future?)

Yes Peter, my main audio system is Bang & Olufsen which causes a whole host of issues (although I shall not be beat!) They do have a multi room system of their own, BeoLink, although to kit out what I am trying to achieve would be an astronomical cost!

To get over this and provide quality audio to 6 other rooms (3 already B&O) I am using a Denon AV DSP Receiver & Amp that allows a variety of inputs, including 5ch surround and 2 concurrent amplified outputs. I plan to use 1 of the outputs for TV / DVD / HDTV etc and the other audio, PC -> B&O 3200 -> Denon !!

I can currently control the B&O gear via an IR converter from a company called Lintronic which (I assume although not yet tried!) can be triggered from HomeGate via a call to "my software" with a parameter for each action.

The problem I face is that the audio from the Denon output is then streamed to all 6 rooms, to which I require some kind of PC controllable switcher. Xanatech do offer such a product although IR controlled (can be overcome using emitters from the aforementioned converter) although is quite expensive as it is a complete solution (the majority redundant to me!)

I was considering creating a custom built solution myself controlled via RS232 although given "free time" is limited I would prefer an "off-the-shelf" solution / band aid for the time being.

Once again thanks for the advice & information
(goes to show the value of this forum, especially for the information hungry UK Cbusites!)

Cheers
Greg...

 

Hi Greg
Not sure if this is what your after but worth a look..........

http://www.oceancontrols.com.au/controllers/serial_daq_k108.htm


Its an rs232 controlled device which has relays

HTH
Frank

 

Thanks Frank, the link is very useful.

It looks just what I'm looking and price is very low (AUD->GBP) compared with similar systems over here! Xantechs 6 speaker IR switch is approx. ?500GBP where as Oceans In/Out RS232 controller is about 40GBP.

Given up to 10 can be daisy chained on 1 serial cable; potentially giving control of 50 relays for ?400.

I guess our government will slap a whole lot of duty / tax on it to take the shine of it a little and it will take about 3 months to get here (AUS to UK=2-3 days and the remaining time to come 200m down the road!) but still worth a trial!

Cheers
Greg

Tried to order 2 multidrop boxes but their eccomerce failed! I will try again tommorow!

 

> Tried to order 2 multidrop boxes but their eccomerce failed! I will try again >tommorow!


Let me know if you cant get thru and i can give them a ring .....


Frank

 

I am still not sure if you are planning to switch the line level in or the speaker level out. Either way, I think you will need to find relays that "Make before Break". The reason for this is "speaker thump" when the load changes. I think you will find that you will need to present some form of permanent load to either the input or the output to help minimise this effect.

Colin Smith

 

Hey Greg,


Have you thought of using some of the other output devices in the family, like the 0-10V DC analog output, perhaps to drive a VCA-style audio switch, or even adding a C-Bus to DMX converter and using any number of audio control products which respond to that particular protocol?

If you're looking into DIY, I remember that Elektor magazine has published a couple of interfaces that can decode DMX in recent years. It might be a little long-winded way to get there, but by adding DMX you are really opening your house to a whole other world of devices...



Greig.