Dual 505 update
 

On 9/03/2015 2:15 AM, Java Jive wrote:
As I said earlier, these days manufacturers take even less care with
vinyl than they do with other media sources.

CD technology could and should have given us a flat FR from near DC up
to 25kHz, easily covering the range of human hearing.

**Bull****. With a sampling rate of 44.1kHz, Nyquist tells us that the
theoretical maximum of CDs is 22.05kz.


Even going up
to 22kHz it still covers quite comfortably the range of older
listeners such as myself.

**It actually covers pretty much everyone over the age of 10.


So to all intents and purposes we could and
should be getting near perfect audio reproduction. But what do we
actually get? While there are some very good quality CDs available,
even of those recordings originally released on vinyl, there are also
too many examples where the sound has been ruined by over-processing.
As has been said many times before, the fault lies not in the
technology, but in the people who use it

**Duh.


--
Trevor Wilson
www.rageaudio.com.au

---
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Dual 505 update
 

In article ,
Bob Latham wrote:
Did you not in the late 70s replace twin flex speaker cables that came
with the speakers with QED 79 strand? I did and couldn't believe how much
difference it made.

I've never had speakers that 'came with twin flex'

But adequately rated twin flex is just fine. Or even adequately rated
solid core.

--
*All men are idiots, and I married their King.

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

Dual 505 update
 

In article ,
Bob Latham wrote:
If I could arrange for the above test to be done in my room with my kit
in particular the speakers and with a range of speaker cables I have
some say in, I'm confident I could pass the test.

The very fact you have a range of speaker cables suggests you expect to
hear a difference. And when you expect such a thing, you often think you
do.

--
*Go the extra mile. It makes your boss look like an incompetent slacker *

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

Dual 505 update
 

In article , Bob Latham
wrote:
In article , Dave Plowman (News)
wrote:
In article , Jim Lesurf
wrote:
I'm quite happy to accept others can hear things that pass me by.
But where's the beef?

I'm happy to accept others may hear things differently too. But then
you get comments like 'you must be deaf if you can't hear the
difference I can'. In which case it should be easy to identify the
'better' cable without seeing what is in use.

Of course having spent a lot of money on new cables - obviously
expecting them to be better otherwise why bother - its easy to
convince yourself there is a difference.

Seems the cash prize may still be on offer:-

http://gizmodo.com/305549/james-rand...les-are-better

Did you not in the late 70s replace twin flex speaker cables that came
with the speakers with QED 79 strand? I did and couldn't believe how
much difference it made.

I assume you're asking Dave that. FWIW I tried various cables many years
ago and then settled on the one with the lowest series resistance and
modest series inductance. Not really because of any difference I could hear
but simply because it made sense in principle to minimise any change in
frequency response given that I could.


If I could arrange for the above test to be done in my room with my kit
in particular the speakers and with a range of speaker cables I have
some say in, I'm confident I could pass the test.

I will admit I've not heard cables sound different on other speakers or
in others rooms but to be honest I can't recall ever trying.

I'm only qualifying the cables choice to prevent the examiner providing
3 pretty identical cables. I've never thought I could hear differences
in all cables.

Oh and I can't prove one cable is better than another. I can under the
right circumstances characterise them and pick my personal preference.

The test referred to was never about showing which was 'best'. Just to find
out if someone could actually *show* they could hear the differences they
claimed when they only had the sound to decide with.

As I'm sure you know full well already (but others reading this may not)
the basic problems here are that;

1) Its easy to show that people hear 'differences' even when faced with the
same source material played on exactly the same setup (inc cables). Reason
being that human perceptions change with time, and with having previously
heard sounds.

2) That people are affected by expectations and other cues. So knowing what
change has or had not been made can affect the results even when the person
believes it hasn't.

Hence it is good practice to do tests in ways that deal with those factors
and see if someone could tell when a change had been made when they *only*
have the sounds to go on.

Jim

--
Please use the address on the audiomisc page 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

Dual 505 update
 

On Mon, 09 Mar 2015 12:58:54 +1100, Trevor Wilson
wrote:

On 9/03/2015 2:15 AM, Java Jive wrote:
As I said earlier, these days manufacturers take even less care with
vinyl than they do with other media sources.

CD technology could and should have given us a flat FR from near DC up
to 25kHz, easily covering the range of human hearing.

**Bull****. With a sampling rate of 44.1kHz, Nyquist tells us that the
theoretical maximum of CDs is 22.05kz.

As it was actually implemented it was something of a compromise,
sacrificing FR to give greater playing time, but the space available
on the prototype technology "COULD AND SHOULD" (note what I actually
wrote) have been allocated differently to give us a shorter playback
time at a higher sampling rate that would have covered the range of
human hearing.

Even going up
to 22kHz it still covers quite comfortably the range of older
listeners such as myself.

**It actually covers pretty much everyone over the age of 10.

I and several others tested the range of our hearing in the Physics
Lab at college when I was about 17 or 18, and I wasn't the only one in
the group who could hear above 23KHz at that age.

So to all intents and purposes we could and
should be getting near perfect audio reproduction. But what do we
actually get? While there are some very good quality CDs available,
even of those recordings originally released on vinyl, there are also
too many examples where the sound has been ruined by over-processing.
As has been said many times before, the fault lies not in the
technology, but in the people who use it

**Duh.

Duh indeed!
--
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Dual 505 update
 

On Mon, 09 Mar 2015 14:27:49 +0000 (GMT), Jim Lesurf
wrote:

http://www.st-andrews.ac.uk/~www_pa/...eshift/cp.html

The authors claimed they'd found an 'effect' where the cable delayed
signals by an amount that varied with the current level. But when I looked
at the details I noticed that they'd changed something in their test rig
without realising the consequences. I think the authors were honest. But
people make mistakes.

I wrote to the author about this. He had changed the current in part
by changing the load resistor. This, naturally enough, interacted with
the cable reactances to give a different group delay. I'm not sure he
really understood (a background in microwaves really helps), and I
never saw a retraction.

d

Dual 505 update
 

In article ,
Java Jive wrote:
As it was actually implemented it was something of a compromise,
sacrificing FR to give greater playing time, but the space available
on the prototype technology "COULD AND SHOULD" (note what I actually
wrote) have been allocated differently to give us a shorter playback
time at a higher sampling rate that would have covered the range of
human hearing.

The reasons for the original CD spec are all based around the limits of
the PCM recorders of the day - basically a semi-pro video recorder
(U-matic).

As we know from later, CD itself is capable of a longer playing time.

I doubt there's much in the way of musical information above about 15 kHz
anyway. Excepting some electronic stuff.

--
*I stayed up all night to see where the sun went. Then it dawned on me.*

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

Dual 505 update
 

In article , Don Pearce
wrote:
On Mon, 09 Mar 2015 14:27:49 +0000 (GMT), Jim Lesurf
wrote:

http://www.st-andrews.ac.uk/~www_pa/...eshift/cp.html

The authors claimed they'd found an 'effect' where the cable delayed
signals by an amount that varied with the current level. But when I
looked at the details I noticed that they'd changed something in their
test rig without realising the consequences. I think the authors were
honest. But people make mistakes.

I wrote to the author about this. He had changed the current in part by
changing the load resistor. This, naturally enough, interacted with the
cable reactances to give a different group delay.

Indeed.

I'm not sure he really understood (a background in microwaves really
helps), and I never saw a retraction.

FWIW I did know one of the authors (Harrison, or 'Harry') enough to
exchange some emails with him at one point. This was because he was one of
the editors of HFN at the time I started writing for them. [1] I'd guess
his main involvment was in writing and being interested in the topic. So
the 'technical' side was, I guess, done by Ben Duncan.

Alas, I am less then entirely 'whelmed' by some other things Ben Duncan has
written. e.g the reports he wrote for Uncle Russ about RFI and fancy mains
cables.

So I'm curious to know which one you wrote to, and what reply he made if
any. My guess is you tried Ben Duncan.

Jim

[1] He beat me to buying a collection of back issues of HFN that reached
back to issue one! Damn! I still lack a few issues from the first few
volumes. :-/

--
Please use the address on the audiomisc page 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

Dual 505 update
 

On Mon, 09 Mar 2015 18:38:18 +0000 (GMT), Jim Lesurf
wrote:

In article , Don Pearce
wrote:
On Mon, 09 Mar 2015 14:27:49 +0000 (GMT), Jim Lesurf
wrote:

http://www.st-andrews.ac.uk/~www_pa/...eshift/cp.html

The authors claimed they'd found an 'effect' where the cable delayed
signals by an amount that varied with the current level. But when I
looked at the details I noticed that they'd changed something in their
test rig without realising the consequences. I think the authors were
honest. But people make mistakes.

I wrote to the author about this. He had changed the current in part by
changing the load resistor. This, naturally enough, interacted with the
cable reactances to give a different group delay.

Indeed.

I'm not sure he really understood (a background in microwaves really
helps), and I never saw a retraction.

FWIW I did know one of the authors (Harrison, or 'Harry') enough to
exchange some emails with him at one point. This was because he was one of
the editors of HFN at the time I started writing for them. [1] I'd guess
his main involvment was in writing and being interested in the topic. So
the 'technical' side was, I guess, done by Ben Duncan.

Alas, I am less then entirely 'whelmed' by some other things Ben Duncan has
written. e.g the reports he wrote for Uncle Russ about RFI and fancy mains
cables.

So I'm curious to know which one you wrote to, and what reply he made if
any. My guess is you tried Ben Duncan.

Jim

[1] He beat me to buying a collection of back issues of HFN that reached
back to issue one! Damn! I still lack a few issues from the first few
volumes. :-/

Yes it was Ben Duncan. The article was so detailed - and so wrong. It
was the first time I had thought to set a published record straight.

d

Dual 505 update
 

On Mon, 09 Mar 2015 17:37:01 +0000 (GMT), "Dave Plowman (News)"
wrote:

The reasons for the original CD spec are all based around the limits of
the PCM recorders of the day - basically a semi-pro video recorder
(U-matic).

As we know from later, CD itself is capable of a longer playing time.

Well that rather goes to show that it would have been better to have
chosen from the start a spec that completely encompassed the range of
human hearing, rather than one that almost does.

I doubt there's much in the way of musical information above about 15 kHz
anyway. Excepting some electronic stuff.

Are you claiming that there is no difference between Audio-Cassette,
which rolls off about there, and open-reel, vinyl, and CD, all of
which had higher roll-offs?. I suspect that most people would be able
to tell the difference immediately between the frequency response of
AC and those other types - I certainly could and still can with no
problem at all.

After some searching I've just found some AC recordings of tracks from
an album that I now have on CD, it's Barbara Dickson's seminal folk
album "From The Beggar's Banquet", 1970. The AC recordings were
originally made from a library copy of the LP, while the CD is a
re-issue of 5 or 6 years ago that I feel most fortunate to have
obtained. The difference between the two is utterly unmistakable.
--
================================================== =======
UK Residents: If you feel can possibly support it
please sign the following ePetition
before closing time of 30/03/2015 23:59:

http://epetitions.direct.gov.uk/petitions/71556
================================================== =======
Please always reply to ng as the email in this post's
header does not exist. Or use a contact address at:
http://www.macfh.co.uk/JavaJive/JavaJive.html
http://www.macfh.co.uk/Macfarlane/Macfarlane.html