How to connect two sources for one set of B&W CM9 speakers

Discussion in 'AV Pre-Amp/Processors & Power Amps' started by ndaulah, Nov 26, 2010.

  1. ndaulah

    ndaulah
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    Hi I am completely new with setting up music system.

    Is there any way to connect the same set of speakers to two different sources?

    I would like to have the speakers connected to my AV receiver for the home theater system, and also to a pre-amp for my stereo system.

    I am guessing it wouldn't be a good idea to have them hooked directly to the speaker at the same time.

    Is there any way to choose which source will used for the speaker?

    I guess the obvious way to do it would be to change the unplug and plug the wires at the back when switching between systems. But I would really appreciate any suggestions to automate the process.
     
  2. Mark.Yudkin

    Mark.Yudkin
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    Connecting both simultaneously is a recipe for catastrophic failure of all components.

    Automatic switch: Sonance source switch. Also Speakercraft & Russound make these.

    Mechanical switch: Beresford router.

    It's a cost vs convenience question: the Beresford is cheaper, but you have to physically press the button each time.
     
  3. ndaulah

    ndaulah
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    Thanks for the reply Mark,

    I was also considering a source selector, but the guy at the hifi store said that it would compromise the music quality. (Funny that he didn't mention that connecting two sources to the same speaker isn't a good idea)

    Would you know which of the switches you have mentioned would be better at preserving the sound quality.
    Also are both of these compatible with high current amplifiers?
     
  4. Mark.Yudkin

    Mark.Yudkin
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    I only linked to switches that I consider capable of complete preservation of every little audio nuance within their operating limit. Regarding current handling, the links provide access to the technical specifications, which you can consult should you be concerned. I would not have thought that the B&W CM9 were particularly heavy current drawers - they're not ESLs with low impedance characteristics.

    Needless to say, you ought to be able to arrange to borrow a switch to test, as I did with the miscellaneous Sonance automation components I'm using.
     
  5. MI55ION

    MI55ION
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    As an alternative to the speaker switch and so long as the AVR has 5/7.1 multi channel pre-outs you can simply use a pair of RCA cables to combine the two amps:

    - Connect only the L/R channels of the AVR's multi pre-outs to an unused line input on the stereo amp (e.g. DVD).

    - Connect the stereo amp direct to the speakers.

    - Max* out the volume on the stereo amp (e.g selecting DVD input) and re-calibrate all you speakers using the AVR (you only have to do this once!). In effect from now on the stereo amp is a slave and works as power amp with volume being controlled by the AVR whenever you are using surround source.

    - Remember to put the volume down on the stereo amp when you decide to listen to CDs etc.

    * Some people will remind you why its a bad idea to max out the volume since if you forget to lower the volume and change source it could potentially damage the speakers/amp. If you don't trust yourself or others who will be using your kit choose a 'safe' level (usually half way) and make that your reference point, again calibrating all your speakers on the AVR so that levels are matched.

    There are a number of advantages of doing it this way, most notably in reference to sound quality. You lighten the load on the AVR and potentially lower distortion, provide more power and greater headroom for the centre and surround channels. The front L/R channels also benefit from the (usually) superior strengths of a stereo amp. If your stereo amp has a feature called 'home theatre bypass' then even better as when this in engaged the stereo amp will perform as a power amp only and you don't have to change the volume level. The main disadvantages when switching sources are you have to press the input select button and set the volume to your 'reference point'. A minor inconvenience but enough to put some off! Of course if you are of the environmentally friendly type, you might care what effect it has on energy consumption since you're running two amps as opposed to just the one. :eek:

    It sounds far more complicated than it is. If you have a spare set of RCA cables lying around and the AVR has preouts, why not give it a try. You might be in for a surprise! ;)
     
  6. ndaulah

    ndaulah
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    Do you know where I can source the Sonance AS2. I called the Sonance Distributor but they gave me the number of a guy who hasn't answered his phone yet.
    All the searches I have done online for Sonance products come up with the AL2 or the AL2S which are line level switches and not speaker level.
     
  7. Mark.Yudkin

    Mark.Yudkin
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    They're readily available over here (CH), but I have no idea about your unspecified country.

    In the UK, the importer is Armour Home, and your dealer ought to be able to obtain their products. Russound may be easier to locate, dealers are listed at Russound - Authorized Dealer Locator.
     

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