In article ,
Serge Auckland wrote:
I would have thought any history of surround sound for recording would
contain more than a passing mention of Ambisonics. It seems to me
like the Betamax of surround sound - technically superior but poorly
marketed.

Roy.
Yes, I agree in part, but what I was trying to do was to explain the
origins of surround sound as it applied originally to vynil. I don't
think that Ambisonics was poorly marketed as much as just too late. By
the time ambisonics came about, the public was fed up of "quadrophonic"
systems that didn't work. Anyway, I question the whole premise of
surround sound through four (or five) loudspeakers. It relies on
pair-wise phantom images which just don't work in practice. As we know,
frontal phantom images work quite well, rear phantom images work after
a fashion, but don't provide accurate localisation, and sideways
phantom images hardly form at all. For classical music (which is the
only format Nimbus has tried ambisonics, as far as I know) it will work
OK for ambiance, but not for remote soloists. 5.1 surround works for
films with the distraction of pictures, but not terribly well for
music. Unless some sound-field synthesis system can be evolved that
doesn't require 200 'speakers (see my earlier posts on the subject)
we're stuck with pair-wise phantom images, and consequently ambisonics
or otherwise, poor surround sound.

By far and away the most impressive stereo I've heard was yonks ago in a
near anechoic listening room at BBC Wood Norton. It was the old chapel in
Wood Norton hall - so large and an irregular shape - and heavily treated
to reduce unwanted reflections. With an pair of BBC LS 3/1 which had 15"
bass units with a pair of concentric HF1300 tweeters, the imaging was
stunning - with any out of phase material coming from well outside the
nominal sound stage, even from behind.

No commercial surround system - then or now - got even close on the
variety of material we listened to. Over the months I was there on a
course my colleagues brought in their own systems which we all listened to
- and the results were still impressive.

Which left an undying impression that spending money on acoustic treatment
of your listening room is far better spent than many thousands on the
finest amplifier, etc.

Oh - and the current fad for laminate floors and blinds rather than
carpets and curtains means you're on a hiding to nothing.

--
*I like cats, too. Let's exchange recipes.

Dave Plowman London SW
To e-mail, change noise into sound.

On Mon, 20 Feb 2006 00:13:03 +0000 (GMT), Dave Plowman (News) wrote:


In article ,
Roy roy wrote:
I would have thought any history of surround sound for recording would
contain more than a passing mention of Ambisonics. It seems to me like
the Betamax of surround sound - technically superior but poorly
marketed.

It was never marketed. Superb though it is, the costs were horrendous.
Four full bandwidth speakers and amps - one for each corner - and a
further four good quality speakers and amps (but not necessarily with as
good a bottom end) for the sides.

4 channels == horrendous? Never set up a dolby prologic system by adding
another amp and speakers? Not everybody does surround sound with a crappy
5 channel integrated receiver.

On Sun, 19 Feb 2006 21:03:16 -0000, "Serge Auckland"
wrote:


"Roy" roy wrote in message ...

"Serge Auckland" wrote in message
...
This is a long post, so those not interested can ignore it.

This brief history is not exhaustive, and covers mostly surround sound as
applied to records. There were separate developments for broadcasting,
and these have been mentioned in passing, but not covered in detail. I
have also not discussed Ambisonics in any detail.


I would have thought any history of surround sound for recording would
contain more than a passing mention of Ambisonics. It seems to me like the
Betamax of surround sound - technically superior but poorly marketed.

Roy.
Yes, I agree in part, but what I was trying to do was to explain the origins
of surround sound as it applied originally to vynil. I don't think that
Ambisonics was poorly marketed as much as just too late. By the time
ambisonics came about, the public was fed up of "quadrophonic" systems that
didn't work. Anyway, I question the whole premise of surround sound through
four (or five) loudspeakers. It relies on pair-wise phantom images which
just don't work in practice. As we know, frontal phantom images work quite
well, rear phantom images work after a fashion, but don't provide accurate
localisation, and sideways phantom images hardly form at all. For classical
music (which is the only format Nimbus has tried ambisonics, as far as I
know) it will work OK for ambiance, but not for remote soloists. 5.1
surround works for films with the distraction of pictures, but not terribly
well for music. Unless some sound-field synthesis system can be evolved that
doesn't require 200 'speakers (see my earlier posts on the subject) we're
stuck with pair-wise phantom images, and consequently ambisonics or
otherwise, poor surround sound.

S.



One of the problems for Ambisonics was that the patents were assigned
to the NRDC, a famously incompetent bureaucracy that killed quite a
few good ideas in the 70s.

The point of the ambisonic system is that it is a storage/transmission
system that is independent of the reproduction environment. The theory
is that three channels are all that is needed for accurate recording
of directional information in a circle, and that four channels can
completely encode directional information in a sphere. The way it is
reproduced is entirely dependent on the decoder and as many speakers
as needed can be used. The Meridian decoders allow 7 speakers, with
varying layouts, and others have designed decoders using many more
speakers than this.

The problem with the Nimbus and Unicorn recordings is that they had to
use the UHJ system to matrix into 2 channels and hence degraded the
encoding.

It is something of a joke that a system is available that will enable
accurate encoding of directional information into three channels but
the commercially sucessfull but inaccurate Dolby system uses 5
channels and is now starting to use 7! More than twice as much data
for a worse result.

Incidentally the VHS/beta comparison is not apt. There was very little
actual difference between the wo systems. A moe suitable comparison
would be U-matic to Digibeta.

Bill

In article ,
AZ Nomad wrote:
It was never marketed. Superb though it is, the costs were horrendous.
Four full bandwidth speakers and amps - one for each corner - and a
further four good quality speakers and amps (but not necessarily with as
good a bottom end) for the sides.

4 channels == horrendous?

Eight, actually. And of course the cost of the decoder, which was
expensive too.

Never set up a dolby prologic system by adding another amp and speakers?

You can't 'set up' a Dolby Pro Logic system by simply adding another amp
and speakers. That gives you Hafler. For ProLogic you need a decoder and
amps. But you don't need the same quality speakers for what is basically a
bandwidth limited FX channel carrying different information.

Not everybody does surround sound with a crappy 5 channel integrated
receiver.

Not everyone would pay out perhaps 4 times the cost of a good stereo
system for one with limited uses. Which is why it failed.

--
*Age is a very high price to pay for maturity.

Dave Plowman London SW
To e-mail, change noise into sound.

On Mon, 20 Feb 2006 10:32:05 +0000 (GMT), Dave Plowman (News) wrote:


In article ,
AZ Nomad wrote:
It was never marketed. Superb though it is, the costs were horrendous.
Four full bandwidth speakers and amps - one for each corner - and a
further four good quality speakers and amps (but not necessarily with as
good a bottom end) for the sides.

4 channels == horrendous?

Eight, actually. And of course the cost of the decoder, which was
expensive too.

Never set up a dolby prologic system by adding another amp and speakers?

You can't 'set up' a Dolby Pro Logic system by simply adding another amp
and speakers. That gives you Hafler. For ProLogic you need a decoder and
amps. But you don't need the same quality speakers for what is basically a
bandwidth limited FX channel carrying different information.

Not everybody does surround sound with a crappy 5 channel integrated
receiver.

Not everyone would pay out perhaps 4 times the cost of a good stereo
system for one with limited uses. Which is why it failed.

It failed bacause there was almost no four channel media. The difference
between then and now is prolog encoding of movies during the 90's and
dolby digital DVD and SACD now.

mick wrote:
On Sat, 18 Feb 2006 16:21:11 -0800, Andre Jute burbled:

snip

Your admirably complete par tells me everything I need to know about home
audio: it cannot substitute for a decent hi-fi system. It's still for the
anoraks, and apparently for less discriminating anoraks than those thirty
years ago who I thought deserved four-track sound.


I think you have to look at the current surround-sound idea from a
different viewpoint Andre, as a system to add "realism" to displayed
video. There isn't really any point in heading for "hi-fi" in that
situation as people will tend to concentrate on the screen action anyway.

I understand that now, Mick, after Serge explained. That's why I asked
the question, to determine where HV fits into the scheme of things.

However, I watch perhaps 10 movies a year, plus at most two or three
television programmes a week. That's not enough to justify the effort
of adjusting my attitude or expand the energy to understand the detail
and to set up a proper system.

The sound is of secondary importance (but makes a big difference).
Surround isn't an anorak thing now, but certainly isn't for those in
search of audio nirvana either!

No, it isn't a substitute for a decent hi-fi system, but then again it
isn't intended to be.

Oh - and thanks Serge, that was a most enjoyable read!

Yeah, wasn't that great. And a very readable thread following. Thanks,
fellers.

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

Andre Jute