In article , R. Mark Clayton
wrote:

"Jim Lesurf" wrote in message
...
In article , R. Mark Clayton
wrote:

There will be some difference between 48hpbs per channel on DVD and
192kpbs per channel on Blu Ray, but without "golden ears" you will
have difficulty spotting it (unlike the picture quality).

I'm now curious about the above values (and units). Are "hpbs" and
"kpbs" typos? If so, did you mean "kbps"?

k obviously.

Ok, but see my comment below on what you then wrote later in your reply...


Also, where does the data come from that most DVDs are "48kbps per
channel"? The DVDs I record using standard home recorders generally
use 256kbps or more for the stereo audio. But since most of the
commercial DVDs I have are LPCM I don't know what is usual for
commercial films.

Varies from 16bits 48kbps (slightly better than CD at 44k1bps) to much
higher (24bits @192k)

Erm. what does your "16 bits 48kbps" mean? I assume this is another typo.

'CD' at 44.1 **samples** per second (per channel) delivers a bitrate way
above "48kbps". So you seem to be confusing "kbps" with "samples per
second" above. Hence I'm still not clear what your original assertion
meant. Can you please distinguish between sample rates and bitrates and
explain?

The point I made was that the home recorded DVDs I make tend to be with
bitrates of 256kbs (or more) but in sampling terms are all 48ksample/sec.
And in stereo.

I know that DVDs tend to use 48k *samples/sec* and integer multiples of
that sample rate. So that may explain your earlier comment that they are
"48kbps per channel" (sic) as meaning "48ksample/sec" (per channel) but
still gives no idea what the actual bitrates are if *not* on the disc in
LPCM format.


And going off at a tangent... I'd be interested in the details behind
the idea that the OPs brother can "tell speaker cables in blind
tests". That is an assertion that has appeared countless times over
the years and - in correctly run tests - has never been established to
my knowledge.

Indeed wouldn't mind a wager on this.

The remarkable thing about the 'prize' that was on offer for many years was
that it wasn't a 'bet'. If someone tried and failed they didn't have to pay
anything. They just had to face up to it being clear that they'd failed to
show they could hear what they'd claimed. But if they had succeeded then
thousands of pounds were on offer. Yet no-one even tried. May tell us
something about such claims. :-)


Only exceptions I'm aware of are when the cable either has so much
series impedance that when placed in the system it significantly
alters the frequency response, or causes a marginally stable amplifier
to become unstable. Both of these factors are well known. But all the
other quasi-magical assertions about speaker cables seem unsupported
by correctly run test results.

Whilst it is worth having reasonably thick cables so that they don't get
warm and there are negligible losses on a long run, you are otherwise
unlikely to be able to be able to notice or measure any difference
(apart from fractions of a dB in volume, which can be compensated for).

In principle the series inductance could also be audible for some of the
cables with wide spacing between the conductors and when the cable is long.
But I can't say I've ever found a case where someone showed they could hear
this, either.

snip

I wonder if your DVD player or amp was set up correctly to do 5.1 and
was perhaps instead doing stereo or some variation on Dolby Pro Logic?

Given measurements on other commercial audio products my main
candidate remains that the material is simply being level compressed
in a different way by the makers. This has been found even as a
measurable difference on the CDA and SACD layers of dual-layer discs.
The industry assumption seems to be that 'early adopters' want to hear
and see something 'more impressive' but as the system become 'mass
market' the old faith in 'louder is better' rules and things become
clipped and crushed as the output is dumbed down.

Dunno - nothing would surprise me especially from Sony.

I've forgotten what recordings were used. But the results I know of were
published in the Journal of the Audio Engineering Society and involved a
lot of comparisons using various replay systems, etc.

My own interest has tended to have a different focus - the tendency for
'remastered' CDs of old recordings to be excessively level compressed and
clipped. Madness given the dynamic range CDDA provides. But in the world of
'pop' audio the mantra is 'loudness sells'. So they just crank up the gain
and crush everything into the ceiling!

Alas, although the BBC are generally good at avoiding such problems, when I
looked at their TV iPlayer last summer the TV sound was also clipped and
compressed. Albeit not as badly as some pop/rock CDs. (BBC radio fared much
better.)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Apologies for following up my own posting but I need to correct my own
typos! :-)

In article , Jim Lesurf
wrote:


Varies from 16bits 48kbps (slightly better than CD at 44k1bps) to much
higher (24bits @192k)

Erm. what does your "16 bits 48kbps" mean? I assume this is another typo.

'CD' at 44.1 **samples** per second

should be "44.1k"


(per channel) delivers a bitrate way above "48kbps". So you seem to be
confusing "kbps" with "samples per second" above.

should be "ksamples..."

FWIW The only info I have had on the bitrates for non-LPCM DVD soundtracks
is summarised as part of what I wrote for

http://www.audiomisc.co.uk/audioformats/ddanddvdv.html

I'm asking about this because I don't have data showing what is actually
typical for either commercial DVD-V or BD issues that don't use LPCM.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

On 23/05/2010 20:10, R. Mark Clayton wrote:
wrote in message
...
On 22/05/2010 19:23, R. Mark Clayton wrote:
Depends a bit on how the audio was getting to your amp before.

If say Dobly Pro-logic (stereo with centre and lo-fi back channel) then
this
will sound better than stereo, but well shy of full 5.1. In addition
typically DVD has 48k per channel whereas IIRC Blu-Ray has 192k. You
would
need pretty good ears to notice though.

Audio was getting to my amp on the same optical digital cable as before,
if that was what you meant? Not sure about Pro-Logic/stereo
comparisons....my comparisons have just been between Dolby Digital 5.1 and
DTS 5.1 tracks on DVD, compared to the same kind of audio tracks (or their
down sampled equivalent) on Blu-Ray movies in general. (and in two cases
comparing the actual same movies on BD and DVD).

I don't think I'm a 'golden ears' type...my brother is the sort who can
tell speaker cables in blind tests and all that, but that is so not me. It
must be a much more pronounced difference than any of that. Not at all
uncommon, either, when googling. I've had several friends and family
members notice it now, too, with no prompt from me to seek a
difference....just the general "wow, that sounds much better" type
comments.


Odd. Does the difference persist when DVD's are played on your Blu Ray
player?


No.


--
Legend-11
Forget about Ronaldo.
Your Carlos Tevez too.
'Cos we've got a player who's United through and through.
He just might tw*t your groundsman, and bomb down your wing,
He's French, he's fast, he's f*cking CLASS, so hear United sing:
Tra la laa, it's Patrice Evra, tra la laa laa laa laa laa...