"tony sayer" wrote in message
...

Yes understand that it was all about processing and no real reason from
Auntie as usual why its done differently on FM and not DABble and
DTV.....

I don't know what Auntie says, but I would expect the processing to be quite
different on DAB and FM as the effects of the overall transmission link are
different on the two systems. On DAB, provided that there is enough
signal for it to work properly, there is no significant noise associated
with the link. For stereo FM it is a very different matter. Also,
pre-emphasis.

--
Tony W
My e-mail address has no hyphen
- but please don't use it, reply to the group.

"Jim Lesurf" wrote in message
...

One thing I didn't mention on the pages was that I have also been struck
my
how my older recordings from R3 (back from circa 1980) seem to have a
wider
dynamic range despite my having to alter the recording gain at times
because of the limited SNR of domestic cassette and rtr tape.

I would agree with that. I have noticed that the envelope of recent Prom
concert recordings have that flat-topped look which the older ones don't.
I've never found the need to adjust the recording level whilst recording
from the radio as even R3 never had a wide enough dynamic range to justify
that. In any case in the past the background noise of the FM reception was
significantly greater than that from the tape. Nowadays I don't have that
problem as I get a good view of the local FM/DAB transmitter mast from my
living room window.

One advantage of FM that wasn't mentioned was the short delay. I can have
several radios, all tuned to the same station (usually R4), on at the same
time so that I can follow a programme as I move about the house. That
doesn't work with DAB or DTV. If I am recording from the radio nowadays I
usually use my Sky + and then copy from that via the optical SPDIF link to
the computer.

David.

In article ,
David Looser wrote:
One advantage of FM that wasn't mentioned was the short delay. I can
have several radios, all tuned to the same station (usually R4), on at
the same time so that I can follow a programme as I move about the
house. That doesn't work with DAB or DTV.

What is equally galling is that there is a difference between DAB
receivers too - and DTV ones. I dunno if it's intrinsic in the system or
just different makers implementation - I've not had the opportunity to try
two identical ones. Then, of course, you've got the delay some TV
receivers introduce to the sound to bring it into sync with the picture...

--
*I'll try being nicer if you'll try being smarter

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

In article , Dave Plowman (News)
wrote:
In article , David Looser
wrote:
One advantage of FM that wasn't mentioned was the short delay. I can
have several radios, all tuned to the same station (usually R4), on at
the same time so that I can follow a programme as I move about the
house. That doesn't work with DAB or DTV.

What is equally galling is that there is a difference between DAB
receivers too - and DTV ones. I dunno if it's intrinsic in the system or
just different makers implementation - I've not had the opportunity to
try two identical ones. Then, of course, you've got the delay some TV
receivers introduce to the sound to bring it into sync with the
picture...

It is difficult to get to the bottom of such matters. I did try for a while
asking one well-known 'maker' of DAB tuners what the jargon for one of
their prompted 'features' in terms of sound quality actually meant in terms
of what was being done to the data. I never got a clear answer, and suspect
the actual process was developed by someone else who hadn't told them.
Experienced similar responses in some other cases.

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article , Jim Lesurf
scribeth thus
In article , Tony
wrote:
"Jim Lesurf" wrote in message
...
I have now put up a page that compares the dynamics and level
compression on FM with that on DAB. The page can be found at

http://www.audiomisc.co.uk/HFN/DABvs...ewithlike.html

Interesting. I heard a Prom the other night on DAB, Chicago SO playing
Shostakovich 4th symphony. The dynamic range certainly seemed wider
than I am used to on R3 FM.

That is my impression, also. I must admit, though, that during the last
couple of years I have largely abandoned listening to FM


Of course FM has to deal with pre-emphasis, so percussion can be quite
seriously affected.

I don't know if pre-emphasis plays much part in this, but it is an
interesting point. The data does show that any sudden loud peaks have their
level swiftly pulled down on FM R3, and that the gain in a following quiet
period is slowly ramped up.

I can see the point of the compression as it helps pull extended pp periods
above the background noise on FM. But I now prefer digital transmissions
which don't have the problem.

Doesn't that metallic sheen on digital at those rates annoy you
though?..

Course if old Auntie took digital seriously she'd see to it that the bit
rates were higher them 192 on satellite at least!..

Perhaps the old moo is being an arse over the rates on DAB can't be seen
to be any higher on DSAT and DTV delivered radio..

Whereas the rates on DTV are 256 K/bits..

Odd that Dontcha tink?...

Slainte,

Jim


--
Tony Sayer

In article , Tony
scribeth thus
"tony sayer" wrote in message
...

Yes understand that it was all about processing and no real reason from
Auntie as usual why its done differently on FM and not DABble and
DTV.....

I don't know what Auntie says, but I would expect the processing to be quite
different on DAB and FM as the effects of the overall transmission link are
different on the two systems. On DAB, provided that there is enough
signal for it to work properly, there is no significant noise associated
with the link. For stereo FM it is a very different matter. Also,
pre-emphasis.

I often wonder how many people have a good FM aerial and tuner
sometimes;?...

FM is capable of giving excellent results..
--
Tony Sayer

In article , tony sayer

wrote:
In article , Jim Lesurf


Doesn't that metallic sheen on digital at those rates annoy you though?..

....or have you stopped beating your wife? :-)

[snip]
Odd that Dontcha tink?...

Yes. Odd that you seem to be only able to focus on one aspect of a more
complex situation... ;-

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article , tony sayer

wrote:
In article , Tony
scribeth thus
[snip]

I often wonder how many people have a good FM aerial and tuner
sometimes;?...

FM is capable of giving excellent results..

Indeed. Alas, it may require rather more that just "a good FM aerial and
tuner". As with digital transmissions you seem to overlook other factors
which affect the situation when comparing results. :-)

The problem is that many systems are 'capable' of giving excellent results,
but the list of conditions that have to be met in practice for this to be
the case may be longer than you take into account above.

For example, have you ever read Pat Hawker's 1980/81 WW articles on
multipath? I tracked them down and have been reading them as a result of
being told about them on the uk.tech.digital-tv group. They make very
interesting reading. Remarkable that such results seem to have been largely
ignored - maybe for the reasons he suggests in the actual articles...

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf wrote:
In article , tony sayer

wrote:
In article , Tony
scribeth thus
[snip]
I often wonder how many people have a good FM aerial and tuner
sometimes;?...

FM is capable of giving excellent results..

Indeed. Alas, it may require rather more that just "a good FM aerial and
tuner". As with digital transmissions you seem to overlook other factors
which affect the situation when comparing results. :-)

The problem is that many systems are 'capable' of giving excellent results,
but the list of conditions that have to be met in practice for this to be
the case may be longer than you take into account above.


While we are on the subject, do you happen to know the scheme used for
audio on HDTV (via satellite)? When they improved the video resolution I
don't suppose they improved the audio too - or is that too much to hope for?

Cheers

Ian

In article , Ian Thompson-Bell
wrote:
Jim Lesurf wrote:


The problem is that many systems are 'capable' of giving excellent
results, but the list of conditions that have to be met in practice
for this to be the case may be longer than you take into account above.


While we are on the subject, do you happen to know the scheme used for
audio on HDTV (via satellite)? When they improved the video resolution I
don't suppose they improved the audio too - or is that too much to hope
for?

Afraid I don't know the details of the system they use. I think they may
have included the ability to use some form of 'surround sound', but I don't
know anything beyond that at present.

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html