RE: Speaker Switching

["Kevin Hawkins" <lists@xxxxxxx>]

    I suspect although I don't know that the DDAR's are
fairly well
protected against the speakers going o/c - either way a resistor across
the
speaker terminals would not go amiss. As I said the issue is more likely
the
switch of 1 to 6 speaker pairs all onto one input in any combination -
would
this be in any combination or would it always be them all or just any
one/two usually ?  If it was a fairly fixed number there are ways
around
this that will better match the impedance. Also if your announcements
are
mono you can series wire two speakers (left and right) when mono to
double
the impedance which now makes the impedance double what it was before.
Much
closer now to the 4ohm level.
    From memory was this for spoken announcements ? If so
again the input 7
amplifier could be fairly robust and also running at a lowish power -
consequently a lowish cost (mono ? ) unit and therefore you could
probably
get away with running a level of risk - If it was an AV amp I wouldn't
but
in your case maybe the switch is still worth it - the switchable ones
are
quite expensive - I did find an x10 speaker switch at one stage and also
a
serial one though if you want me to dig it out. It was only for four
stereo
speaker sets to 2 sources from memory.

    Kevin
  -----Original Message-----
  From: Tony T [mailto:tony@xxxxxxx]
  Sent: 23 December 2002 15:22
  To: ukha_d@xxxxxxx
  Subject: RE: [ukha_d] Speaker Switching


  Thanks, Kevin.

  I _think_ I understand all that...

  In practice it will be,

  DDAR1 .... DDAR5    ANOTHER
    to        
to       to
  SPKRS1 ..  SPKRS5   SPKRS6

  With a pc soundcard (attached to an amp) being the item switchable
to
  each of the 6 speakers pairs.

  So to be clear, DDAR1 goes only to spkrs1
  DDAR2 goes only to spkrs2 etc etc

  I doubt the ddar's have any protection, but also less power output
than
  a decent amp?

  This is all beyond me, I'll look around for a commercial speaker
  switcher I think :-(

  Thanks again
  Tony T



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