Best way to get Radio 3?
 

"Jim Lesurf" schreef in bericht
...
FWIW I did analyses of various examples of concerts and the plots in the
article are fairly representitive. The analysis/article was directed
specifically at 'proms' on BBC4TV and R3 as this was a very convenient set
of examples for comparison analysis.

But as I understand the advantage of Freeview is mainly in the lesser amount
of processing used compared to FM. The low bitrate still gives it a metallic
sound.

gr, hwh

Best way to get Radio 3?
 

"Glenn Booth" schreef in bericht
...
Eureka 147 was recommended by the ITU for "immediate use" in 1994.
Needless to say, it wasn't twenty years old then. At the time that the
MPEG 1 audio specs were ratified, it was pushing technology in
terms of what could be done in hardware in 'real time'. Plus, I'm not
aware of any 'better' technologies that were available at the time. If
there were any, I'd like to hear about them.

A few years ago, when the receiver prices were still high, very little units
had been sold. At that time the system could have been dropped without
causing much trouble in favor of a system using more efficient coding
technologies.

gr, hwh

Best way to get Radio 3?
 

In article , Glenn Booth
writes
Hi,

wrote in message
.. .
On Thu, 2 Mar 2006 14:07:44 +0000, tony sayer
wrote:

Of
course, you may find it's easier to find a 'decent [FM] tuner' than a
decent DVB-T box, and especially one with a digital output.

Freeview is "clean" there is no doubt about that, but it does have that
metallic artificial digital sound to it that I find very irritating.
Course if the BBC was a pro outfit they'd be on satellite at 256 K/bits
or more but sadly their not. Other European broadcasters seem to be able
to do that!..

I think the whole DAB disaster could have been avoided if they'd
picked a solid technology, but they go for something 20 years old. Its
inexplicably wrongheaded....

Eureka 147 was recommended by the ITU for "immediate use" in 1994.
Needless to say, it wasn't twenty years old then. At the time that the
MPEG 1 audio specs were ratified, it was pushing technology in
terms of what could be done in hardware in 'real time'. Plus, I'm not
aware of any 'better' technologies that were available at the time. If
there were any, I'd like to hear about them.

The technology is now looking rather antiquated, however, and bureaucracy
has ensured that we've ended up with a system that fails in one of it's
stated claims - "DAB fully complies with the tough requirements of the
future". The implementation of DAB we have in the UK fails on this
claim, IMO.


If they had made provision for a downloaDABle codec then that would have
gone a long way towards alleviating the ill's of T-DAB at present.

Heard an ntl (broadcast) guy mutter that at a DAB demo some years ago
now 1997 IIRC....
Regards,

Glenn.



--
Tony Sayer

Best way to get Radio 3?
 

In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes
In article , tony sayer

wrote:
In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes


I have also come to a similar conclusion. When I first started
listening to DTTV (and then DAB) I found the differences from FM quite
noticable, and initially disliked the results. However with continued
listening I decided that quite a lot of this was due to my being
'habituated' to the level compression, noise, and high-level
nonlinearity of FM.

Now, the sound on DAB R3 does seem 'confused' at times,

This is odd 192 K on DTV and 192 K on SAT why the difference?.. Course
we are talking about Radio 3 are we not?.

If by 'SAT' you mean satellite I can't comment as I have no satellite RX.

OK you ought to get one. I've been meaning to get around to sending you
that demo disc . There! see, I haven't forgotten;-))

BTW what do you think of Radio 4 in DAB and DTV...

For speech on DAB it can be ok provided they haven't decided to nick
bitrate for something like the parliament channel. However I don't tend to
listen to R4 in the same way as R3, so would be less likely to notice
details. Also, the general level of care with sound on R4 seems to have
degraded over the years, so there seems more in the way of 'bang up against
the endstops', etc, which I find sounds nasty via any route.

Humm...


but also a lot of the time I now find it much clearer than on FM. Given
a free choice and repeated comparisons over many months I now find I
tend to prefer DTTV or DAB a lot of the time. Mainly I think as a
result of the (relative) lack of level compression, noise, and
high-level nonlinearity. Note, though, that this is for R3, not
necessarily for other stations.

I'm beginning to wonder if theres something wrong with the Angus TX;_0


Might I ask what do you use for TV Jim (if you get time to watch it)
analogue, or DTV via sat or freeview...

Panasonic TV. Its own sound output sounds poor even via its phonos, etc.[1]
It presumably decodes NICAM as this is stereo, but the distortion on music
at high signal modulation is easily noticable. This is feeding its phono
outputs to the amps I use.

I therefore tend to use/prefer DTTV, and feed spdif from a nokia 221T to a
Meridian 263 DAC. In general, this seems to produce good results. Indeed,
the 221T for DTTV was the source I used for the comparisions/comments in
the March 2006 HFN article.

DTV is knocking away at 256 K IIRC so it should be good!...

It may well be that a good NICAM demodulator would give better/equal
results. But I've not personally found a TV that delivers good sounds, and
the 221T + 263 seems good to me.

However, as with radio, the actual quality for TV will vary a lot from
station to station and item to item.


Quite..

I actually meant what do you think of the picture!!!
Slainte,

Jim

[1] The TV gives a nice picture,

What the "digital" picture?..

but the sound via its speakers is awful,
and even with its volume set to 'nil' you can still hear noise from its
speakers if you put your ear near them. Ludicrous amount of noise post the
volume control. Really no excuse these days for so much noise from a line
level. However I'm afraid that I only expect crap sound from an actual TV
set, so I just bypass all this for normal use.


--
Tony Sayer

Best way to get Radio 3?
 

In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes
In article , tony sayer

wrote:
In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes


Not in my experience. What it does have is a tendency to lack the
audible effects of level compression, background noise, and high-level
nonlinear distortion of FM.

Where are you finding this high level non linearity Jim?. Can you
elaborate please?...

The "high level" refers to the signal. If you examine the distortion
characteristics of FM the level of distortion tends to rise with both the
signal level and with the modulation frequency. Note that the measurements
quoted in maker's specs and in magazine reviews (when they used to actually
measure this) tended to be for 30 per cent modulation at a frequency like
300 Hz - 1 kHz. Also mono.

I've got a top notch FM exciter in my workshop at the moment here is the
spec sheet or some of it..

10Hz to 15kHz, ±0.2dB referenced to selected pre-emphasis curve.

FM Signal To Noise Ratio (L or R): 83dB below 100% modulation at 400Hz;
measured in a DC to 22kHz band width with 75μs de-emphasis and DIN “A�
weighting.

Stereo Total Harmonic Distortion: 0.005% or less for any modulating
frequency from 10Hz to 15kHz; measured in DC to 22kHz bandwidth with
75μs de-emphasis.

Intermodulation Distortion (L or R): CCIF: 0.02% (14/15kHz 1:1),

SMPTE: 0.025% (60 and 7000Hz 1:1).

Transient Intermodulation Distortion (DIM) (L or R): 0.005% (2.96kHz
square wave/14kHz sine wave modulation).

Linear Crosstalk: L+R to L-R and L-R to L+R due to amplitude and phase
matching of L&R channels (DC-15kHz): 85dB below 100% modulation
reference.

Non-linear Crosstalk: L+R to L-R and L-R to L+R due to distortion
products: 75dB below 100% modulation reference, DC-15kHz.

All specifications referenced to any single output frequency (87-108MHz)
nominal rated output power, and 50 ohm, isolated, non-reactive load.

Must get round to measuring that through the Audiolab sometime, but I
tell you this, most people are hard pressed to tell the difference on
most source materiel with the CD on one input and the output of the
tuner on the another . Course this bears no resemblance to real world
conditions, but thats down to what the BBC decided to do with it before
it hits the air!..

These days, though, the makers and magazines have tended to 'solve' this
problem in the same was as they'd dealt with the similar issue of
nonlinearity in pickup cartridges for LP. Just ignore it and hope no-one
notices or cares... :-)

If you measure 'higher levels' - i.e. modulation depths up to 100 percent,
and higher frequencies, and also L or R or L-R, or intermod, the amount of
distortion rises.

What depth do you mean in an FM system?..

I suspect that. like myself, you have measured the distortion of more than
one FM RX whilst trying to align or tweak it, or just to see if it was
working as it should. it is easy enough to get THDs of the order of 0.2
percent for 300Hz 30 percent mod mono. But when you then measure higher
(signal) levels, etc, the results can be somewhat different. Ditto for HF
intermod or L+R and L-R intermod.

Haven't done that for quite somewhile but a Denon we're using as an RBR
receiver was down to .06% at 10 K at 50 K dev a while ago....

The above occurs even for an 'ideal' RX and is due simply due to the finite
bandwidth and the removal of the higher terms of the modulation by the
bandwidth restriction. This, and avoiding modulation clipping is why BBC R3
have always tended to err on the side of keeping down the modulation.

Nope, they have to keep to what the government decrees, they keep the
mod to where they have to via their encoder/processor the where they
think it ought be within that constraint....
--
Tony Sayer

Best way to get Radio 3?
 

"tony sayer" wrote in message
...
In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes
In article , tony sayer

wrote:
In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes


Not in my experience. What it does have is a tendency to lack the
audible effects of level compression, background noise, and high-level
nonlinear distortion of FM.

Where are you finding this high level non linearity Jim?. Can you
elaborate please?...

The "high level" refers to the signal. If you examine the distortion
characteristics of FM the level of distortion tends to rise with both the
signal level and with the modulation frequency. Note that the measurements
quoted in maker's specs and in magazine reviews (when they used to
actually
measure this) tended to be for 30 per cent modulation at a frequency like
300 Hz - 1 kHz. Also mono.

I've got a top notch FM exciter in my workshop at the moment here is the
spec sheet or some of it..

10Hz to 15kHz, ±0.2dB referenced to selected pre-emphasis curve.

FM Signal To Noise Ratio (L or R): 83dB below 100% modulation at 400Hz;
measured in a DC to 22kHz band width with 75?s de-emphasis and DIN "A"
weighting.

Stereo Total Harmonic Distortion: 0.005% or less for any modulating
frequency from 10Hz to 15kHz; measured in DC to 22kHz bandwidth with
75?s de-emphasis.

Intermodulation Distortion (L or R): CCIF: 0.02% (14/15kHz 1:1),

SMPTE: 0.025% (60 and 7000Hz 1:1).

Transient Intermodulation Distortion (DIM) (L or R): 0.005% (2.96kHz
square wave/14kHz sine wave modulation).

Linear Crosstalk: L+R to L-R and L-R to L+R due to amplitude and phase
matching of L&R channels (DC-15kHz): 85dB below 100% modulation
reference.

Non-linear Crosstalk: L+R to L-R and L-R to L+R due to distortion
products: 75dB below 100% modulation reference, DC-15kHz.

All specifications referenced to any single output frequency (87-108MHz)
nominal rated output power, and 50 ohm, isolated, non-reactive load.

Must get round to measuring that through the Audiolab sometime, but I
tell you this, most people are hard pressed to tell the difference on
most source materiel with the CD on one input and the output of the
tuner on the another . Course this bears no resemblance to real world
conditions, but thats down to what the BBC decided to do with it before
it hits the air!..

These days, though, the makers and magazines have tended to 'solve' this
problem in the same was as they'd dealt with the similar issue of
nonlinearity in pickup cartridges for LP. Just ignore it and hope no-one
notices or cares... :-)

If you measure 'higher levels' - i.e. modulation depths up to 100 percent,
and higher frequencies, and also L or R or L-R, or intermod, the amount of
distortion rises.

What depth do you mean in an FM system?..

I suspect that. like myself, you have measured the distortion of more than
one FM RX whilst trying to align or tweak it, or just to see if it was
working as it should. it is easy enough to get THDs of the order of 0.2
percent for 300Hz 30 percent mod mono. But when you then measure higher
(signal) levels, etc, the results can be somewhat different. Ditto for HF
intermod or L+R and L-R intermod.

Haven't done that for quite somewhile but a Denon we're using as an RBR
receiver was down to .06% at 10 K at 50 K dev a while ago....

The above occurs even for an 'ideal' RX and is due simply due to the
finite
bandwidth and the removal of the higher terms of the modulation by the
bandwidth restriction. This, and avoiding modulation clipping is why BBC
R3
have always tended to err on the side of keeping down the modulation.

Nope, they have to keep to what the government decrees, they keep the
mod to where they have to via their encoder/processor the where they
think it ought be within that constraint....
--
Tony Sayer

I recognise that spec.......Still giving good service?

S.

Best way to get Radio 3?
 

In article , Chris Isbell
writes
On Thu, 02 Mar 2006 17:45:22 +0000 (GMT), Jim Lesurf
wrote:

2) started to suspect that the 'warmth' on FM was due to a combination of
peak-compression (so enhancing the sustain part of notes) and the high
levels of nonlinearity for HF peaks from the RX.

Hence I found that my preference started to change, and now is quite
different to my initial reactions to DTTV.

My experience echoes this.

I have also taken a recording of a CD track from Radio 3 FM and
compared it with my copy of the same CD. The level of compression
surprised me, as did the euphonic effect of this making the FM version
seem more 'alive' (probably because of the higher level of background
noise).


Well the is begs a question on what they do with the signal before it
hits your aerial. Now FM is processed on Radio 3 because it makes
listening in cars and other less so environments easier i.e. you don't
have to fiddle with the volume control so much.

Now they haven't as yet done that on DABble they had / have DRC but
don't seem to use it for this as yet even if they ever will. But than
DAB will be the same as FM. But they don't compress it all the time its
much less in the evening, and I don't blame them for doing that in the
day as very very few people will be listening under ideal conditions....

When the opportunity arises, I will try the same thing with Radio 3 on
satellite. (This obviously depends on the BBC broadcasting a track
from a CD that I possess. ;-)

Fine..
--
Tony Sayer

Best way to get Radio 3?
 

In article , hwh
writes

"Jim Lesurf" schreef in bericht
...
FWIW I did analyses of various examples of concerts and the plots in the
article are fairly representitive. The analysis/article was directed
specifically at 'proms' on BBC4TV and R3 as this was a very convenient set
of examples for comparison analysis.

But as I understand the advantage of Freeview is mainly in the lesser amount
of processing used compared to FM. The low bitrate still gives it a metallic
sound.

Yes.. seems your hearing is what it should be;-))

gr, hwh



--
Tony Sayer

Best way to get Radio 3?
 

In
Nope, they have to keep to what the government decrees, they keep the
mod to where they have to via their encoder/processor the where they
think it ought be within that constraint....
--
Tony Sayer

I recognise that spec.......Still giving good service?

S.


Well its been off air for a while now and was replaced by an analogue
exciter as that was deemed to be LOUDER 'cos wossisnamme at Radica said
it would be, and Jimbo is a loudness freak.

It was in use the other week for an RSL for 209 Radio and one afternoon
there was a Jazz piece on there that was recorded by the guy presenting
the programme and the sound was superb in the car:), really was, sounded
like the guitar was out there on the pavement somewhere and the vocalist
was sitting on the bonnet!..

If they get a full time licence its going there and thats going to be a
really good station:))
--
Tony Sayer

Best way to get Radio 3?
 

In article ,
hwh wrote:
Eureka 147 was recommended by the ITU for "immediate use" in 1994.
Needless to say, it wasn't twenty years old then. At the time that the
MPEG 1 audio specs were ratified, it was pushing technology in
terms of what could be done in hardware in 'real time'. Plus, I'm not
aware of any 'better' technologies that were available at the time. If
there were any, I'd like to hear about them.

A few years ago, when the receiver prices were still high, very little
units had been sold. At that time the system could have been dropped
without causing much trouble in favor of a system using more efficient
coding technologies.

Few units had been sold because those who wanted 'quality' sound didn't
buy it - although at the high bit rates then on offer it was fine.

Now it has taken off due to offering a wide choice of stations at low
quality on most it's rather too late to complain.

--
*Everybody lies, but it doesn't matter since nobody listens*

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