Dynamics and level compression - FM vs DAB
 

In article , Jim Lesurf
scribeth thus
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? :-)

Wouldn't think if it!, shes got some dodgy Russian genes in there
somewhere;! Someone cut her up at the traffic lights the other week and
then they both arrived in the same car park together standing your
ground came to mind;!..!!

[snip]
Odd that Dontcha tink?...

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

No not all all 'n all...

Slainte,

Jim


--
Tony Sayer

Dynamics and level compression - FM vs DAB
 

In article , Jim Lesurf
scribeth thus
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".

But that does help enormously, as does a good tuner. But just how many
of them do you see around?. All they do in this area if fit those poxy
halo things;(..

As with digital transmissions you seem to overlook other factors
which affect the situation when comparing results. :-)

Nothing wrong with digital transmission as such, just the way they go
about that and implement it;(..


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.

Don't dispute that..

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...

Well nothing that a directional aerial won't help much towards for
serious listening;)..

Slainte,

Jim


--
Tony Sayer

Dynamics and level compression - FM vs DAB
 

Alas, it is many years since I have been able to attend a Prom in person.
Distance and decrepitude deter. One reason why the broadcasts and my
recordings of them are now important to me!

Your excused seeing that the RAH is a very long way away;)..

Its bad enough for us here in Cambridge..if you want to do most anything
afterwards like dinner or go for a drink you'll miss the last train home
and taking the motah;!.. Not too good and idea..as is an overnight
stay..

And its never that comfortable an experience either. Was at the St John
Passion cramped up in a circle seat all others having been taken..its
rather difficult for me with work and other commitments to book in
advance and the other seats aren't really that much better for the 18
stone frame;!..


These days I tend to prefer the BBC4 TV Proms to R3. I have gained two
impressions wrt ambience. One is that there often seems to be some LF
noise, perhaps due to air conditioning or passing traffic. However it may
be the audience swaying or breathing! :-)

Well the audience can only be -quiet- for short periods do bear in mind
that most of the poor old souls are seemingly over 50 odd and creak ands
wheeze a bit, there are some young, mainly Asian females;)..

Don't recall seeing any differences in the mic arrangements and thats
are well darkened so they don't show they seem to be smaller every
year.. Or so it appears;)..

The other is that this varies in being noticable from one Prom to another.
Indeed, I get the impression that the entire sound balance changes from one
to another. Not sure how much this is the orchestras playing differently,
though.

Dunno really .. most all the ones I've attended the mics are still
rigged the same 'tho thats no reliable indicator of what your going to
hear..

The sound in most of the hall is different to what you will hear at home
anyway..


For example, the BPO/Rattle Prom of Brahms/Shostakovich seemed to have
richer (louder) bass strings than some other proms.

For perhaps obvious reasons such ambient noise seems louder when there is
something like an extended violin solo. But I am not sure how much this is
mic useage, change in overall recording/broadcast gain, or my hearing
adapting, or my winding up the volume at home!

I think mics do respond to that better then the 'uman lughole!..


Nevertheless, the result of my comparison was that I changed my mind
about the warm ambience of R3/FM and began to enjoy the restored dynamic
range of R3/DAB (and now R3/DTTV and BBC4/DTTV).

The way the BBC handle processing isn't --that-- logical!..


Even so, I think the human brain's audio appreciation capability is very
adaptive if its pre-conceptions will let it just get on and enjoy the
music.

Indeed.. And very enjoyable most all of it was. Sometimes I just go to
see something out of the usual run of the mill and the experience can be
very good like the Rameau last year with the Soweto musicians and
French dancers:))

However what's very good to know is that most of the time the audiences
are at capacity, like the Bach day the other week on a Sunday the 4 PM
concert of Simon Preston on Organ was standing room only as was the
evening:))..


Yes. If digital broadcasting hadn't appeared I'd probably still be happy
enough with FM apart from the background noise level and the way ignition
interference can pop up at the most annoying/distracting moments. But these
limitations where what drove me to try digital in the first place.


I reckon that old local FM TX of yours is an RBR one!..

Anyway if the BBC were serious about digital they could up the bits on
Satellite where the is plenty of bandwidth available and leave FM for
more localised broadcast and scrap the useless T-DAB system and replace
that with something more suited to the 21st century.

DAB isn't just about sound quality, there are some serious deficiencies
in the system if your a broadcaster too especially a commercial one!..


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 presume
this ties in with what Trevor Butler reported and that the BBC simply
didn't apply automated level compression in past days as they do now.

Its called "processing";-!..


I do sometimes notice level adjustments on the BBC4 prom broadcasts, but
they give me the feeling they are being done by a human who is following
the score and tweaking with intelligence to make the result. Not done any
comparisons as yet, but I have the impression that when they put Proms on
BBC1/2 they use more level compression. I do have one or two examples of
the same performance on both BBC4 and BBC2 so may use them to check this
when the necessary round tuit is in stock. :-)

I thought since you retired you had a lot more;)...

Slainte,

Jim


--
Tony Sayer

Dynamics and level compression - FM vs DAB
 

In article , Jim Lesurf
scribeth thus
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.


As far as terrestrial DAB goes its what's done with the bits before it
hits the tuner..

Satellite with an External DAC is the way to go for serious
listening:))..
--
Tony Sayer

Dynamics and level compression - FM vs DAB
 

In article , tony sayer

wrote:
In article , Jim Lesurf
scribeth thus


For example, have you ever read Pat Hawker's 1980/81 WW articles on
multipath?

Well nothing that a directional aerial won't help much towards for
serious listening;)..


Your reply indicates you haven't read his articles! I must admit that the
more I have looked at this topic, the more curious I have become that it
has largely been ignored by broaddcasters, etc, over the years.

I now suspect the problems are more common than is generally realised,
and that fixing it isn't always a simple matter of having a decent
tuner and good antenna (alignment). That may well help, but isn't
a panacea.


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

Dynamics and level compression - FM vs DAB
 

In article , tony sayer

wrote:



Even so, I think the human brain's audio appreciation capability is
very adaptive if its pre-conceptions will let it just get on and
enjoy the music.

Indeed.. And very enjoyable most all of it was. Sometimes I just go to
see something out of the usual run of the mill and the experience can be
very good like the Rameau last year with the Soweto musicians and
French dancers:))

I was really impressed last year by the above - and by the Simon Bolivar
YO. Both were delightful unexpected surprises. Special events that made
me really wish I'd been in the hall. But also examples of why I still
hold the BBC in high regard for organising such events and putting them out
on R3 and BBC4.

I've also been more and more impressed by the various other 'youth
orchestras' like the Mahler and our NYO of BG. They have seemed to me to
really put some feeling into the music, as well as bags of skill, in recent
years. Excellent that they are proms and appear on TV.

Regardless of all else, I'm happy to regard the license fee as a payment
to allow me to enjoy the proms each year. Anything else - bonus. :-)

I wish they'd put *every* prom onto BBC4, though. Particularly annoying
this year that they didn't cover all the Vaughan Williams works despite
it being a special year for VW. Instead the focussed on Messiaen, who
isn't really my personal favourite. Why on earth weren't items like
the VW 7th on BBC4? Why snip out the 'Job' from the VW special
concert?



I do sometimes notice level adjustments on the BBC4 prom broadcasts,
but they give me the feeling they are being done by a human who is
following the score and tweaking with intelligence to make the result.
Not done any comparisons as yet, but I have the impression that when
they put Proms on BBC1/2 they use more level compression. I do have one
or two examples of the same performance on both BBC4 and BBC2 so may
use them to check this when the necessary round tuit is in stock. :-)

I thought since you retired you had a lot more;)...

Ah, well, I retired because I was running low of them... :-)

These days I work more slowly, or decide to shelve many things. For example
I've been putting off sorting out my old Tandberg TP41 portable radio. This
is one of the few portables that I've found deliver an excellent sound. But
it has taken to eating batteries. (Or rather, flattening the NiCads I've
put into it in a few days instead of a charge lasting months!) Something
inside needs adjusting or replacing, but as yet I haven't found the problem
and fixed it. Been on the list for a tuit for well over a year.

Tried a couple of times, but failed. Mind you, the circuit diagram is a
shambles and notes in scandihovian don't help me much. ;-

I recall some Toshiba data sheets that had "Important Note:" followed by
two lines of Japanese. Never did find out if I was doing something wrong!

Alas, other things crop up, or I lack time. So work that I would have done
quickly a decade ago now seems to take ages to get to. And these days I
often struggle to see small details of circuit boards even when using my
reading glasses. My brain is probably crumbling, as well...

Mind you, having said the above, I do seem to end up spending time doing
some things. e.g. the measurements I've been doing on LS cables took ages.
Did plan more, but have abandoned that in horror. Maybe next year... ;-

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

Dynamics and level compression - FM vs DAB
 

In article ,
Jim Lesurf wrote:
I now suspect the problems are more common than is generally realised,
and that fixing it isn't always a simple matter of having a decent
tuner and good antenna (alignment). That may well help, but isn't
a panacea.

It's the case in this part of Sauf Lunnon. Despite a large yagi and no
nearby tall buildings I can't get a clean R4 FM signal. And here, DAB or
Freeview sound rather better than FM on this particular station. Nor can I
hear much difference if any between FreeView and DAB on R4. Or R3.

--
*Most people have more than the average number of legs*

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

Dynamics and level compression - FM vs DAB
 

In article , Jim Lesurf
scribeth thus
In article , tony sayer

wrote:
In article , Jim Lesurf
scribeth thus


For example, have you ever read Pat Hawker's 1980/81 WW articles on
multipath?

Well nothing that a directional aerial won't help much towards for
serious listening;)..


Your reply indicates you haven't read his articles!

No as it 'appens .. I haven't..

Got an online reference for them?..

I must admit that the
more I have looked at this topic, the more curious I have become that it
has largely been ignored by broaddcasters, etc, over the years.

Well its not really a broadcaster problem Jim after all what can they do
about it?..


I now suspect the problems are more common than is generally realised,
and that fixing it isn't always a simple matter of having a decent
tuner and good antenna (alignment). That may well help, but isn't
a panacea.

No under serious cases it won't but it does got a long way over and
above those simple Halo jobbies;!..

--
Tony Sayer

Dynamics and level compression - FM vs DAB
 

In article , tony sayer

wrote:
In article , Jim Lesurf
scribeth thus

For example, have you ever read Pat Hawker's 1980/81 WW articles on
multipath?

Well nothing that a directional aerial won't help much towards for
serious listening;)..


Your reply indicates you haven't read his articles!

No as it 'appens .. I haven't..

Got an online reference for them?..

No, afraid not. After the references were given in uk.tech.digital-tv I
found them in my uni library and took xerox copies. However if you send me
your postal address by private email I can perhaps post you a printed copy
if you wish. Snag here is copyright as it is a WW article so I assume it
would be wrong to simply put a copy online - but maybe someone has done
this. If so, I don't know about it. It seems OK to make one or two copies
for research purposes. But not to make it openly available, I fear.

Similarly, I'd like to have copies of some of the refs he quotes, but fear
these may be difficult to track down. I will be giving it a try, though.

FWIW The copyright situation for such things does vex me at times. There is
a lot of interesting technical data in old WW, or HFN issues. But their
status isn't quite the same as academic journals as it would be easy tread
on the toes of those who own copyright.

Personally, I'd love it if copyright law allowed all technical journal
articles to be freely republished after, say, 10 years. Would make finding
reference material much easier and avoid wheel reinventions. Alas, those
who have a cash interest and own the copyright for magazine articles can be
- quite understandably - against this. I would wish to respect their wishes
as I accept the material is theirs to dispose of.

I must admit that the more I have looked at this topic, the more
curious I have become that it has largely been ignored by
broaddcasters, etc, over the years.

Well its not really a broadcaster problem Jim after all what can they do
about it?..

IIRC one of the comments Hawker makes is along the same lines. The classic,
"Well, it was alright when it left us." :-) However it strikes me as
somewhat naughty if they are saying this *knowing* that the results may
well be much poorer for a large section of the audience for reasons outwith
the listener's control. ...unless they move house!

The problem here, I suspect (again as IIRC Hawker indicates), is that the
broadcasters and set makers were 'promoting' FM for many years and this was
uphill work [pun]. This was fair enough as the competition in those days
was AM, and so FM was pretty likely to be better. But it may mean they
glossed over - and then forgot about - these problems and just how likely
they are. Again fair enough if the choice is FM with some multipath versus
the interference-ridden AM.

Indeed, I assume most RF engineers haven't ever really been aware of this
issue in more than general terms, and respond as you have done with the
assumption that a good antenna, etc, will be a fix. This is 'conventional
wisdom'. I accepted it for many decades and only started to feel it was
doubtful when I wanted to write an article about multipath and began to
study the topic for myself. This followed my increasing puzzlement that so
little previous work seemed findable in the literature.

Now, of course, there are many other transmission/distribution systems and
the choice isn't as simple as it was a few decades ago. So perhaps time for
the skeletons in the FM cupboard to be revealed. :-)


I now suspect the problems are more common than is generally realised,
and that fixing it isn't always a simple matter of having a decent
tuner and good antenna (alignment). That may well help, but isn't a
panacea.

No under serious cases it won't but it does got a long way over and
above those simple Halo jobbies;!..

I agree that in many cases using a good directional antenna - correctly
aligned - plus a good tuner will reduce the effects of multipath. But in
practice I fear it isn't that simple a lot of the time. Hawker has some
comments on this that stuck me as quite perceptive.

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

Dynamics and level compression - FM vs DAB
 

In article , Jim Lesurf
scribeth thus
In article , tony sayer

wrote:



Even so, I think the human brain's audio appreciation capability is
very adaptive if its pre-conceptions will let it just get on and
enjoy the music.

Indeed.. And very enjoyable most all of it was. Sometimes I just go to
see something out of the usual run of the mill and the experience can be
very good like the Rameau last year with the Soweto musicians and
French dancers:))

I was really impressed last year by the above - and by the Simon Bolivar
YO. Both were delightful unexpected surprises. Special events that made
me really wish I'd been in the hall. But also examples of why I still
hold the BBC in high regard for organising such events and putting them out
on R3 and BBC4.

Indeed..


I've also been more and more impressed by the various other 'youth
orchestras' like the Mahler and our NYO of BG. They have seemed to me to
really put some feeling into the music, as well as bags of skill, in recent
years. Excellent that they are proms and appear on TV.

Regardless of all else, I'm happy to regard the license fee as a payment
to allow me to enjoy the proms each year. Anything else - bonus. :-)

I wish they'd put *every* prom onto BBC4, though. Particularly annoying
this year that they didn't cover all the Vaughan Williams works despite
it being a special year for VW. Instead the focussed on Messiaen, who
isn't really my personal favourite.

Well beg to differ on that one but the BBC really ought to televise a
lot more cant cost them that much surely?..
Why on earth weren't items like
the VW 7th on BBC4? Why snip out the 'Job' from the VW special
concert?



I do sometimes notice level adjustments on the BBC4 prom broadcasts,
but they give me the feeling they are being done by a human who is
following the score and tweaking with intelligence to make the result.
Not done any comparisons as yet, but I have the impression that when
they put Proms on BBC1/2 they use more level compression. I do have one
or two examples of the same performance on both BBC4 and BBC2 so may
use them to check this when the necessary round tuit is in stock. :-)

I thought since you retired you had a lot more;)...

Ah, well, I retired because I was running low of them... :-)

These days I work more slowly, or decide to shelve many things. For example
I've been putting off sorting out my old Tandberg TP41 portable radio. This
is one of the few portables that I've found deliver an excellent sound. But
it has taken to eating batteries. (Or rather, flattening the NiCads I've
put into it in a few days instead of a charge lasting months!) Something
inside needs adjusting or replacing, but as yet I haven't found the problem
and fixed it. Been on the list for a tuit for well over a year.

Tried a couple of times, but failed. Mind you, the circuit diagram is a
shambles and notes in scandihovian don't help me much. ;-

I recall some Toshiba data sheets that had "Important Note:" followed by
two lines of Japanese. Never did find out if I was doing something wrong!

Alas, other things crop up, or I lack time. So work that I would have done
quickly a decade ago now seems to take ages to get to. And these days I
often struggle to see small details of circuit boards even when using my
reading glasses. My brain is probably crumbling, as well...

Mind you, having said the above, I do seem to end up spending time doing
some things. e.g. the measurements I've been doing on LS cables took ages.
Did plan more, but have abandoned that in horror. Maybe next year... ;-

Slainte,

Jim


--
Tony Sayer