Re: Impedance Matching Volume Control

[isw <isw@xxxxxxxxxxx>]

In article <KOWdnT6VP8AaAAHYnZ2dnUVZ_revnZ2d@xxxxxxxxxxx>,
 "Robert L Bass" <robertbass1@xxxxxxxxxxx> wrote:

> > Look into 70 volt (70.7 V, to be precise)
> > audio distribution systems.
>
> I disagree.  70-Volt (and 25-Volt) systems are primarily used for offices.
> Most are mono -- not stereo.

If you only run two wires, mono is all you get, transformers or not. It
should be pretty obvious that it takes at least three wires (and two
sets of transformers) to deliver two channels. It should also be obvious
that 70-volt transmission systems can be used for two-channel sound
systems -- and in fact are, regularly.

> Sound quality is what you expect in an elevator.

In fact, it is possible to buy 70-volt audio transformers that have
pretty decent characteristics (i.e. better than the speakers you intend
to drive with them)?

70 volt transmission systems solve a lot of other pesky problems,too;
not least of which is the ability to get lots of volume from good
speakers in a big room while not blowing out the small ones in a
bathroom. IOW, the reason professionals use that method is NOT because
it's low in quality or low in cost.

Isaac