"Arny Krueger" wrote in message
...
"mc" wrote in message

That's the future - and the amps are in the speaker
'cause the crossover is digital, too.

This suggests that the ancient practice of designing the
amp and the speaker as a system (instead of designing a
perfect amp and, separately, a perfect speaker) might
even come back...

It's here, at least in audio production and sound reinforcement.

Integrated speaker/amplifiers are just about practical if you're thinking
stereo. For home theater, or any application requiring more than 2
channels, it's probably more practical to stay with a multi-amp module
feeding all the speakers. The issue is the number of wires that must be
connected--either to the control amp or the line voltage--and how to switch
all of them on/off from a single position.

For example, 5 speakers would require line voltage for all 5, as well as a
signal. These line voltages would have to be supplied from the same point
so that they're easy to turn off at once; either that, or there would have
to be a control signal simplexed down the coax that carried the audio.

Come to think of it, that's not a bad idea; a single coax carrying the audio
in digital form could be looped from speaker to speaker. The user would
have the choice of feeding all the speakers from a mecca, or looping from
one to the next, to the next, etc. The signal would be the same in both
cases. Each speaker would pick off the signal it needs and send the whole
thing to the next speaker.

Because the power supply for each amp would require a power transformer,
this will probably be impractical initially. How about sending both the
signal and the B+, B- voltages from the control amp. This way the power
supplies would come from a large supply capable of supplying the total
filtered rail voltage for all the speakers. The practical advantage of this
scheme would be that one fancy cable would have to be connected to each
speaker. This method would probably close the option of looping from
speaker to speaker.

I'm clearly not an expert on this subject, but several interesting approachs
suggest themselves once the system becomes integrated. My guess would be
that the initial foray would be to supply speaker level signals from all the
amps directly to each speaker, much as the receiver does now--but with
custom design of the amps to match the characteristics of the speakers.
Such an approach would garner about half the advantages of integrated
speakers, while not adding any problems of its own.

This is a fun exercise. Let's keep this thread going.

Norm Strong

Because the power supply for each amp would require a power transformer,
this will probably be impractical initially. How about sending both the
signal and the B+, B- voltages from the control amp. This way the power
supplies would come from a large supply capable of supplying the total
filtered rail voltage for all the speakers. The practical advantage of
this scheme would be that one fancy cable would have to be connected to
each speaker. This method would probably close the option of looping from
speaker to speaker.


RIGHT! Keep 60 Hz AC out of the amplifier altogether. Feed DC and regulate
it further at the receiving end, in each amplifier. Then you have a setup
where cable resistance (within imaginable limits) cannot have any effect on
the audio.

RIGHT! Keep 60 Hz AC out of the amplifier altogether. Feed DC and regulate
it further at the receiving end, in each amplifier. Then you have a setup
where cable resistance (within imaginable limits) cannot have any effect on
the audio.

But cable resistance, within common limits, _already_ has negligable
effect on the audio.

The aesthetics of the idea appeal to me, but I'm still not convinced
there are practical gains to be had here.

mc wrote:

Because the power supply for each amp would require a power transformer,
this will probably be impractical initially. How about sending both the
signal and the B+, B- voltages from the control amp. This way the power
supplies would come from a large supply capable of supplying the total
filtered rail voltage for all the speakers. The practical advantage of
this scheme would be that one fancy cable would have to be connected to
each speaker. This method would probably close the option of looping from
speaker to speaker.


RIGHT! Keep 60 Hz AC out of the amplifier altogether. Feed DC and regulate
it further at the receiving end, in each amplifier. Then you have a setup
where cable resistance (within imaginable limits) cannot have any effect on
the audio.

What is this ? A forum for the terminally technically clueless ?

Graham

wrote in message

"Arny Krueger" wrote in message
...
"mc" wrote in message

That's the future - and the amps are in the speaker
'cause the crossover is digital, too.

This suggests that the ancient practice of designing the
amp and the speaker as a system (instead of designing a
perfect amp and, separately, a perfect speaker) might
even come back...

It's here, at least in audio production and sound
reinforcement.

Integrated speaker/amplifiers are just about practical if
you're thinking stereo. For home theater, or any
application requiring more than 2 channels, it's probably
more practical to stay with a multi-amp module feeding
all the speakers. The issue is the number of wires that
must be connected--either to the control amp or the line
voltage--and how to switch all of them on/off from a
single position.
For example, 5 speakers would require line voltage for
all 5, as well as a signal. These line voltages would
have to be supplied from the same point so that they're
easy to turn off at once; either that, or there would
have to be a control signal simplexed down the coax that
carried the audio.
Come to think of it, that's not a bad idea; a single coax
carrying the audio in digital form could be looped from
speaker to speaker. The user would have the choice of
feeding all the speakers from a mecca, or looping from
one to the next, to the next, etc. The signal would be
the same in both cases. Each speaker would pick off the
signal it needs and send the whole thing to the next
speaker.
Because the power supply for each amp would require a
power transformer, this will probably be impractical
initially. How about sending both the signal and the B+,
B- voltages from the control amp. This way the power
supplies would come from a large supply capable of
supplying the total filtered rail voltage for all the
speakers. The practical advantage of this scheme would
be that one fancy cable would have to be connected to
each speaker. This method would probably close the
option of looping from speaker to speaker.
I'm clearly not an expert on this subject, but several
interesting approachs suggest themselves once the system
becomes integrated. My guess would be that the initial
foray would be to supply speaker level signals from all
the amps directly to each speaker, much as the receiver
does now--but with custom design of the amps to match the
characteristics of the speakers. Such an approach would
garner about half the advantages of integrated speakers,
while not adding any problems of its own.

This is a fun exercise. Let's keep this thread going.

My plan for years (check google, I've been saying this for a long time) has
always been to have a bus - let say 4 wires, two for DC power (about 40
volts) and two for signal. The speakers would be daisy-chained. Speakers
that needed more power than the standard bus could supply could have their
own AC power cord.

The signal bus would be digital audio, all relevant channels multiplexed.
Each speaker would have a switch that selected which channel it would
reproduce.

So, setup would be composed of positioning the speakers, wiring them
together with standard bus cable (both star and link topologies would be
supported) and setting each speaker's switch to match its location.

In this day and age, the signal bus could even be a high-powered version of
USB or Firewire. Or maybe SPDIF or TOSLINK. Yes the signal bus could be
optical on a fiber, or IR broadcast or RF, even WiFi.

On Thu, 29 Dec 2005 18:11:08 -0500, Arny Krueger burbled:

snip

My plan for years (check google, I've been saying this for a long time)
has always been to have a bus - let say 4 wires, two for DC power (about
40 volts) and two for signal. The speakers would be daisy-chained.
Speakers that needed more power than the standard bus could supply could
have their own AC power cord.

snip

When thinking amplifier power distribution you have to think of the Watts
required. If the cable is any reasonable length then you will have Watt
losses in it. IMHO you should look at using an unregulated but well
smoothed supply at a relatively high voltage, say 100V (I would have
suggested twice that but there is a safety issue. The 100V could be
+/-50V to earth at source so would be within most safety regulations), and
then use a DC/DC converter at each speaker to get the stable amplifier
volts requred. That would keep the amps down, allowing lighter bus wiring.
You then have to get rid of the converter noise though!

Cross-posts trimmed to rec.audio.tech only.

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info
Web: http://projectedsound.tk