switching audio with ELV

Is there any problem with switching speaker level signals (eg out of one MRA amplifier) using an ELV to provide audio to two zones? If possible, could I just switch the +ve spkr leads and common the -ve, hence for two pairs of speakers use only two channels of the ELV, not needing to use 4 channels? (I am not talking about commoning left and right negatives, just commoning left -ve room1 with left -ve room2. and switching posatives between rooms through the ELV). This is a cheap option if I never need both zones at same time.

 

That should be OK. I can't think of any problem with it. Ideally, you should do the switching when there is no audio output.

 

I would be very cautious about doing this..

It is not necessarily as simple as switching the speakers..

Depending on the amplifier, speakers and configuration unwarrantable damage could occur to the equipment..

For example..

The 560125 amplifiers can drive 28wrms into a 4 ohm load.. As far as i can see they are not suitable for driving at less than 4 ohm load..

The 560110 amplifier can drive 10wrms into a 6 ohm load.. As far as i can see they are not suitable for driving at less than 6 ohm load..

If you plan on using 4 ohm speakers parralleled through the ELV Relay then when the relay connects the speakers the amplifier will see a 2 ohm load and most likely will run but not for long without damage..

If you use 8 ohm speakers in parrallel then when both soeakers are connected the amplifier will see a 4 ohm load.. This should be ok but if the volume is quite high when the switch is made then the amplifier may behave in an unexpected way due to the load changing..

Audio is a funny beast that you either get or you dont..

I would strongly suggest putting in a second amplifier for the second zones.. more control and much less chance of damaging anything..

Cheers,
Nik

 

EDIT.. Just re read your post again..

Please disregard my previous post due to how u plan on configuring it..

Cheers,
Nik

 

Im not convinced it is cheaper than buying some used audio hardware and taking it to the next level.

 

Thank you Darren, Roosta and tobex for time to consider and reply. With only an existing lighting c-bus, and wanting a simple two room MRA, it could be done with one 25w amp $450, and 2 channels of an ELV (other channels could also be used for other functions) $250 it would be lot less than two 25w amps (considering paralelled Lo level input, let alone matrix or other). If it starts getting up in price I may as well buy a 2 zone receiver for about $1G. The source will be a hidden networked Apple TV, running airplay, to lounge and alfresco.

 

This may not be as simple to implement, however there is a CBUS associated gateway, not that it matters.

You might want to consider the Sonos ZP90 or ZP120 given that it has support from computers, phones, cbus and ipad.

http://www.sonos.com/shop/products/connect.

You idea in principle is sound but it seems over-engineered given what is available on the market for that price. There are times when you have to step back and ask yourself if having a Network Attached Storage (NAS) and CBUS requires that both of them be joined together.

More often than not, you will find that the IT side moves in directions never imagined 5 years ago and to take advantage of that fact it requires parallel systems rather than unified systems.

Though, there are 2 gateways on the market able to convert Sonos into CBUS.

Freeware
http://nodejs.org/
http://www.cbusforums.com/forums/showthread.php?t=7300&highlight=sonos

Commercial



You may find that integration is more enjoyable if you spread your technology out in more optimal combinations knowing that sooner or later you will have total control through CBUS.