"Danny" wrote in message
oups.com...
Hi Jim,

I spoke with you earlier today about this.
I have 3 aux audio inputs that I want to run through my PM-3000
intercom. Thanks,
Danny


I stay as far away from stereo in the aircraft as I can, so I'm sorry I
don't have an answer for you.

HEre's my "canned" answer::

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Stereo In The Aircraft

RST does not produce any stereo intercoms, audio panels, headsets, or other
devices that reproduce stereo music. If you are absolutely determined to
have stereo in your aircraft, you might just as well stop reading now,
because anything we have to say isn't going to change your mind.

We made a conscious business and engineering decision not to produce any
product for stereo. There are good aviation and engineering reasons for
this.

First, a little background music or listening to the ballgame in a cockpit
environment isn't all that bad. Sometimes flying is miles and miles of
nothing but miles and miles. On the other hand, I know from my own love of
music that when there is a particularly good cut playing on my home stereo
and I have the headphones on (try "Sweet Sir Galahad" by Baez or "Minstrel
Of The Dawn" by Lightfoot at somewhere slightly below the threshold of pain
in the 'phones to see what I mean) that I get totally lost within the music
and the world just sort of blurs away. Just about the LAST thing I want in
an airplane is a pilot that has zoned out on music and is just holding the
controls to have something to do with their hands. That's item #1.

Second, stereo is expensive. Yes, I understand that FLYING is expensive,
too, but to go to the expense of specially-designed headphones, intercoms,
audio panels, and all the rest of it seems to us to be on the other side of
reasonable. Our company thrust has, and always will be, to make flying
affordable for everybody. That's point #2.

Now to the engineering stuff. Suppose you try and take your stereo headset
and fly in somebody else's airplane that is "regular airplane". Will your
stereo headset work without the trick little switch on the cable to convert
it to a monophonic headset? No, you will hear one ear of the conversation
only. And what did that little switch do? It put both earphones in
parallel, which cut the impedance of the headset in half. Properly
designed, this MIGHT not be noticeable to the aircraft radio, or it might.
Since airplane radios weren't designed to figure out whether or not you were
messing around with a stereo headset, the manufacturer didn't worry about
making sure his radio would drive that low of an impedance.

Even worse, if somebody else takes his standard aircraft headset and puts it
into your stereo airplane jack, it will short out one of the channels.
Depending on the design of the intercom, the best you can hope for is that
one stereo channel will be dead in everybody's headphones. Second worst is
that the short on that channel will blow out the amplifier for that channel.
In a really lousy design, that short will cause the whole intercom/audio
panel to fail, leaving you without any headphone audio at all.

Given all these reasons, RST has decided not to produce any stereo
equipment. While it probably won't sway your decision for stereo in your
airplane, we thought you should at least consider these problems.

Jim

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