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Posted to uk.d-i-y
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Christmas Snake Oil anyone ?. (V expensive mains extensionblock).
On 27/12/17 11:07, wrote:
On Wednesday, 27 December 2017 10:39:01 UTC, Roger Hayter wrote:
tabbypurr wrote:
On Tuesday, 26 December 2017 23:52:17 UTC, Roger Hayter wrote:
tabbypurr wrote:
On Tuesday, 26 December 2017 22:37:42 UTC, Roger Hayter wrote:
tabbypurr wrote:
An 8ohm speaker is 6-7 ohms dc resistance. A metre of 1mm^2 cable is
44mohm, so 2.5 metres is 0.11ohms. So no detectable difference on the
sound whatsoever.
But a good quality audio amplifier may have an output impedance of
around 50milliohm at low frequencies, so the damping effect on an 8ohm
speaker may be significantly affected by an extra series 110 milliohms.
I already explained why it isn't.
You have explained why it wouldn't be if speaker cabinets contained only
an 8ohm non-inductive resistance. But they wouldn't be much use if
they did..
that isn't what I said. But I can see discussing is a waste of time. This
ever happens when discussing electronics in a diy group.
I know you didn't say that. But your argument only applies rigorously
to a resistor. A speaker contains not only complex reactive elements
but is also non-linear. That doesn't by any means prove you're wrong,
but does make the simple comparison of resistors (which easily 'proves'
the external resistance negligible) an inadequate proof that you are
right.
Speaker resistance is effectively in series with cable resistance and everything else. It makes ultralow source impedance or huge damping factors pointless.
Oh dear oh dear.
NT
--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."
Lucas Bergkamp
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