In article , Pooh Bear rabbitsfriendsand
writes
tony sayer wrote:

In article , Pooh Bear rabbitsfriendsand
writes

Trevor Wilson wrote:

"Pooh Bear" wrote in message
...

Trevor Wilson wrote:

"Pooh Bear" wrote in message
...

wrote:

Simple answer. Purchase a speaker selector switch at any electronics
outlet. The selector switch takes one pair of amplifier outputs and
spilts out the output to 4 and up to 8 stereo pairs. (it takes care
of
the impedance problems).

Pray - tell us - how does it do that - " it takes care of the
impedance
problems " ?

I rather think it does no such thing.

**Some do. The switch boxes typically either perform an internal
series/parallel thing, and/or place a high power (typically) 2 Ohm
resistor
in the path.

I was vaguely wondering about that. Neither approach is a good idea for
fidelity though.

**Of course. My first post outlined the best approach.

Indeed and I agree 100%. At some time in the future decent quality wireless
links will become available using the 2.4GHz band using a method compatible
with
IEC 802.11. I'm actually waiting for a certain company to announce its
commercial availability. Last time I checked it was being held up for ETSI
compliance issues.

Graham


Www.barix.com

any use?......

Last time I looked anythting they had was compressed.

I've been round the loop several times over a year ago and all the consumer
stuff is
the same. They talk of 'high quality' or 'stereo quality' but never ever
mention
it's not linear pcm.

Graham


Apparently so they say, one of their OEM modules does cope with this.
I'll find out before long as we're installing a 3 mile 5 Ghz link that
needs to carry real time PCM....
--
Tony Sayer

Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel separation aren't exactly
great either. Certainly a *big* reduction in quality compared to CD.

Graham

In article , Pooh Bear rabbitsfriendsand
writes
Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel separation aren't exactly
great either. Certainly a *big* reduction in quality compared to CD.

Graham


Beg to differ. Ever tried a numerically controlled exciter such as a
Harris DIGIT CD modulator?.

http://www.broadcast.harris.com/prod...details.asp?sk
u=WWWDIGFMEXCITE
--
Tony Sayer

In article , tony sayer
writes
In article , Pooh Bear rabbitsfriendsand
writes
Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel separation aren't exactly
great either. Certainly a *big* reduction in quality compared to CD.

Graham


Beg to differ. Ever tried a numerically controlled exciter such as a
Harris DIGIT CD modulator?.

http://www.broadcast.harris.com/prod...details.asp?sk
u=WWWDIGFMEXCITE

Except that that link may not have been too clever;(. Follow this one.
Of course not aimed at domestic consumers but as to CD-v-FM
quality....

http://www.broadcast.harris.com/radi...n/exciters.asp
--
Tony Sayer

"tony sayer" wrote in message

In article , Pooh Bear
rabbitsfriendsand writes
Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel
separation aren't exactly great either. Certainly a
*big* reduction in quality compared to CD.

Graham


Beg to differ. Ever tried a numerically controlled
exciter such as a Harris DIGIT CD modulator?.

http://www.broadcast.harris.com/prod...details.asp?sk
u=WWWDIGFMEXCITE

Very impressive, but...

(1) A great FM exciter does not guarantee a clean signal as
received. There's many a slip between the cup and the lip.

(2) As big and expensive as this Harris puppy is, it can
only do 78 dB dynamic range. That can be matched or beaten
by a $70 PC sound card. I'm talking stereo performance
compared to stereo performance.

Again, add antennas, signal path, and even an exceptionally
good FM receiver, and real-world performance through the
whole loop is not all that wonderful by modern standards.

Admittedly the basic performance specs of 78 dB dynamic
range and 0.5 dB FR aren't shabby, but it doesn't compare to
what you can do with digital coding for a tiny fraction of
the price.

(3) The worst thing about FM broadcasting is what they do to
the signal intentionally, not accidentally. Of course we
can't blame the medium for that.

tony sayer wrote:

In article , tony sayer
writes
In article , Pooh Bear rabbitsfriendsand
writes
Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel separation aren't exactly
great either. Certainly a *big* reduction in quality compared to CD.

Graham


Beg to differ. Ever tried a numerically controlled exciter such as a
Harris DIGIT CD modulator?.

http://www.broadcast.harris.com/prod...details.asp?sk
u=WWWDIGFMEXCITE

Except that that link may not have been too clever;(. Follow this one.
Of course not aimed at domestic consumers but as to CD-v-FM
quality....

http://www.broadcast.harris.com/radi...n/exciters.asp
--
Tony Sayer

I'm not sure what your point is.

No 'processor' can get over the basic problems relating to FM transmission /
reception that are inherent to the technique.

Are you aware of how the 'stereo' is extracted from the one transmitted
signal ? It isn't exactly a 'clean' process !

Graham

In article , Pooh Bear rabbitsfriendsand
writes
tony sayer wrote:

In article , tony sayer
writes
In article , Pooh Bear rabbitsfriendsand
writes
Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel separation aren't exactly
great either. Certainly a *big* reduction in quality compared to CD.

Graham


Beg to differ. Ever tried a numerically controlled exciter such as a
Harris DIGIT CD modulator?.

http://www.broadcast.harris.com/prod...details.asp?sk
u=WWWDIGFMEXCITE

Except that that link may not have been too clever;(. Follow this one.
Of course not aimed at domestic consumers but as to CD-v-FM
quality....

http://www.broadcast.harris.com/radi...n/exciters.asp
--
Tony Sayer

I'm not sure what your point is.

Just to point out that you aren't that correct in the statement that,

Certainly a *big* reduction in quality compared to CD.

Isn't that accurate as such.


No 'processor' can get over the basic problems relating to FM transmission /
reception that are inherent to the technique.

Its not a processor at all!. Its just an exciter, that's the bit that
makes up the drive (carrier and modulation) that you then amplify up to
the desired power level required for the service cover you wish to
provide in an FM transmission system.

The processor will be in front of that, but that in itself is used for
other reasons.



Are you aware of how the 'stereo' is extracted from the one transmitted
signal ? It isn't exactly a 'clean' process !

It isn't as bad as you seem to think. FWIW I had one of these units
outside the listening room because its quite noisy, cooling fans etc,
and drove that with a Sony CD player with a pro AES/EBU output and
another output direct to a power amp driving a pair of Quad ESL63
speakers. In front of an audience of Six hi-fi types very few could tell
the difference, let alone repeatedly, between direct and off-air via an
Audiolab tuner.


Of course this may not a a very worthwhile experiment/demo as very few
will get to hear an FM TX of that calibre directly driven and without a
Processor in line.....
--
Tony Sayer

In article , Arny Krueger
writes
"tony sayer" wrote in message

In article , Pooh Bear
rabbitsfriendsand writes
Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel
separation aren't exactly great either. Certainly a
*big* reduction in quality compared to CD.

Graham


Beg to differ. Ever tried a numerically controlled
exciter such as a Harris DIGIT CD modulator?.

http://www.broadcast.harris.com/prod...details.asp?sk
u=WWWDIGFMEXCITE

Very impressive, but...

(1) A great FM exciter does not guarantee a clean signal as
received. There's many a slip between the cup and the lip.

Yes agreed..


(2) As big and expensive as this Harris puppy is, it can
only do 78 dB dynamic range. That can be matched or beaten
by a $70 PC sound card. I'm talking stereo performance
compared to stereo performance.

Again, add antennas, signal path, and even an exceptionally
good FM receiver, and real-world performance through the
whole loop is not all that wonderful by modern standards.

It's streets ahead of the poxy DAB system that we suffer in the UK
Arny;!...


Admittedly the basic performance specs of 78 dB dynamic
range and 0.5 dB FR aren't shabby, but it doesn't compare to
what you can do with digital coding for a tiny fraction of
the price.

We are talking about "radio" broadcasting ?..

(3) The worst thing about FM broadcasting is what they do to
the signal intentionally, not accidentally. Of course we
can't blame the medium for that.

Agreed;( or perhaps ;(



Of course the original poster was stating that FM was nowhere near CD
quality.

For real "CD quality" you need UK DAB !.

Still the BBC are doing very well knocking out the Proms on VHF FM and
with the old Optimod's switched out and very fine a sound it is too)..

Even despite the odd acoustics of the old Albert Hall!.....

--
Tony Sayer

Arny Krueger wrote:
"tony sayer" wrote in message

In article , Pooh Bear
rabbitsfriendsand writes
Mark wrote:

FM radio transmitter

Receiver in each room,

FM's rather noisy Mark. Distortion and channel
separation aren't exactly great either. Certainly a
*big* reduction in quality compared to CD.

Graham


Beg to differ. Ever tried a numerically controlled
exciter such as a Harris DIGIT CD modulator?.

http://www.broadcast.harris.com/prod...details.asp?sk
u=WWWDIGFMEXCITE

Very impressive, but...

(1) A great FM exciter does not guarantee a clean signal as
received. There's many a slip between the cup and the lip.

(2) As big and expensive as this Harris puppy is, it can
only do 78 dB dynamic range. That can be matched or beaten
by a $70 PC sound card. I'm talking stereo performance
compared to stereo performance.

Again, add antennas, signal path, and even an exceptionally
good FM receiver, and real-world performance through the
whole loop is not all that wonderful by modern standards.

Admittedly the basic performance specs of 78 dB dynamic
range and 0.5 dB FR aren't shabby, but it doesn't compare to
what you can do with digital coding for a tiny fraction of
the price.

(3) The worst thing about FM broadcasting is what they do to
the signal intentionally, not accidentally. Of course we
can't blame the medium for that.

To cover 1 house you can use 10 mW and have essentially noise free
reception...

and you can use ordinary RF receivers and even portable radios outside
if you like.

I have an FM link at home and it is very handy.

I agree, you can get better performance on paper using a digital link
with special receivers etc etc etc. But its probably not relevent for
the application.

Mark