"Jim Lesurf" wrote in message
...
A while ago there was some discussion about loudspeaker cables and the
relative merits of analysis using the transmission line and AC lumped
element approachs. I've now done a page on this which people may find
interesting. It is at

http://www.st-andrews.ac.uk/~www_pa/...g/howlong.html

Note that I decided to put this on the Scots Guide not AudioMisc. This is
because the page shows a fair bit of 'hard sums' - i.e. the algebra for
the
two approaches. However even if hard sums make your head ache, the results
may be of interest. :-)


**Nice work Jim. It backs up what I've been telling people for a couple of
decades. As Phil has stated, what would be interesting would be to do the
same analysis with real-world speakers. Particularly ESLs. I've measured one
pair which has a response that falls to less than 1 Ohm at about 17kHz. Low
inductance cables tend to be essential with such speakers.


--
Trevor Wilson
www.rageaudio.com.au

In article , Trevor Wilson
wrote:


**Nice work Jim. It backs up what I've been telling people for a couple
of decades. As Phil has stated, what would be interesting would be to
do the same analysis with real-world speakers.

I am creeping up on that. :-) The webpage does show results for 4 - 32
Ohms resistive to indicate that any resistive load value which is broadly
similar to a speaker doesn't change the conclusions much. The page was just
to make the basic point and show the analysis methods.[1] However...

The HFN articles use a series of loads - resistive, capacitive, inductive,
as well as open and short. They compare measurement with theory and get
suprisingly good agreement. I also ended up including things like 'internal
impedance' (aka skin effect) and how it alters the behaviour of cables

I am also in the process of examining the use of squarewaves, and the use
of a load more like a speaker. i.e. one with a complex impedance that has
some peaks and dips.

However for obvious reasons I have broken this up over a series of
articles. All too much for just 3-4 A4 pages! The measurements also took
weeks to do and analyse. The webpage just uses old results by other people,
but I have done my own measurements on various cables, and details should
appear in due course. In fact, there is so much that as with some previous
articles I will probably end up doing 'extended' versions on the web six+
months after the magazine version appears.

FWIW The first HFN article should appear in the next issue. Now seen and
checked a PDF of the page layout. The other articles will appear in
following months, but there will be some breaks and diversions for articles
on other topics.

BTW Although I chose the cables 'at random' from a long list I compiled it
seems clear that 'A' was the old 'Monitor Audio' branded cable claimed to
be '8 Ohm'. For that, the values I have were measured by Jim Moir and
published in HFN. Detailed references in the articles.

Slainte,

Jim

[1] One reason for the webpage is that is will allow me to give it as a
reference if I wish in a magazine article. I wanted readers who are
interested to be able to see the models I used, but to avoid putting 'hard
sums' into the magazine and making the actual article difficult for those
who don't like maths. Given the models anyone else can - if they wish - do
similar work with other loads, cable lengths, etc, etc.

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
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