"Wally" wrote in message
...
Keith G wrote:

What's the tune/artist in this first extract, Keith?

It's the 'Honeysuckle Suite: I. Sugar Maple/II. Elm/III. Sweetgum' -
on side 2 of the Rachel's 'Selenography' double album. I've got the
vinyl (needless to say) but it's available on CD for notta lotta
money:

http://www.amazon.co.uk/Selenography.../dp/B00000IR6T

Thanks for that - will lay me hands on it sooner or later.


There's not much harpsichord on that or any other Rachel's album, Wally -
have a look at these sites for an idea; there's some video and audio to be
found, if you scrunt about a bit:

http://www.rachelsband.com/index.html

http://www.rachelgrimespiano.com/

In article , Powell
wrote:

"Jim Lesurf" wrote

My speakers have four spikes beneath them which makes it a pain to
move the speakers even slightly as the length of at least one
spike has to be adjusted to make all four rest on/in the floor.
(The floor is solid - maybe concrete - and not wood.)

"concrete"... is a very good vibration sink compared to wood, for
example.

What size/shape/structure/type of "concrete" do you have in mind, and
what do you mean by "sink"? Can you point pun me at measurements to
support what you say?

In theory, all things being equal (concrete's mass will convert more
sound energy to heat more efficiently as compared to wood which tends to
resonate.

Afraid that reads like a rather muddled set of assertions to me. Which "all
things" are you setting "equal"? What do you mean by "concrete's mass"? Do
you mean 'density', or what?

How does 'concrete' having 'mass' mean it disspates vibration more easily
than the same 'mass' of wood?

What about the question of coupling between the different mechanical
impedances which may mean that less energy transfers? etc, etc.

All solid structures have a tendency to 'resonate'. But since you still say
nothing about the structral sizes and shapes, nor the internal wave
impedances, velocities, or dissipation factors, nor how the coupling
depends on many factors, your assertion isn't one you have actually
explained.


Many high end speaker manufactures like Wilson Audio, B&W,
Egglestonworks and others construct speaker cabinets out of synthetic
compounds, stone, or aluminum for this reason., for example. Of course
in practice it is more a complicated subject because of Q value effects.

Meausrements... yes, I have data. What is your specific question?

Provide the specific measurements (and how you did them) that back up the
specific assertions you make above. We could then decide if your views are
supported by measurements you (or others) have made, nor not.

If this is a carpet and pad installation over concrete it is unlikely
that spikes will work anyway, IME.

"Work" means?...

For maximum effectiveness spikes should not be run through any type of
carpet interface (carpet/foam).

You have now traded one word (work) you didn't define for a phrase
(effectiveness) which you also haven't defined. What is your measureable
definition for these terms?

If you have high quality carpet, spikes just won't penetrate the
carpet/pad substrate.

Well, I do have spikes on one of the pairs of speakers I use. And I had no
trouble getting them to penetrate the thick carpet and underlay. However I
don't know that the spikes do much beyond stopping the speakers wobbling a
bit if I bump into them. However...

The problem here is as already referred to in this thread. That various
people make all kinds of confident assertions about how spikes/cones
'work'. But they often do so in vague and sweeping ways, providing no
evidence beyond assertions. And the 'reasons' they assert often conflict
with one another. This seems to apply both to the behaviour of spikes, and
the behaviour of the materials and objects they link.

Quality casters make a good alternative (measured reduction in
cabinet vibration) to speaker spikes, IME.

Ah. Thanks, can you give a URL for the measurements you are referring
to here?

I've not placed this data on the web.

OK. So you are just presenting your opinions without presenting any of your
(claimed) evidence. Thus no-one can tell if what you claim stands up, or
that your evidence actually supports your assertions. Nor, indeed, if you
actually have any evidence.

Since my background is in science and engineering, I do tend to prefer to
base my own conclusions on being able to assess measured evidence, and the
details of how those measurements were obtained. Given that consumer audio
is awash with 'technobabble' I tend to place more reliance on that than on
simply accepting assertions.

Thus far I am left with the feeling that your assertions do muddle up
different physical properties. This isn't unusual. Many people with no
serious background in physical science or engineering can confuse things
like 'strength' and 'rigidity', 'mass' and 'density', etc, etc. However if
you don't provide any measurements of your own, and can't even point to
ones by others that support your assertions, I can't reach an actual
conclusion. I can only decide that your opinions have not been given any
reliable basis upon which others can assess them.

FWIW I think Keith Howard did do some measurements on some of the effects
of 'spikes' a few years ago for HFN. I also think there are lists of values
of the relevant material properties in 'Structure-Borne Sound' by Cremer,
Heckl, and Ungar. I do have a copy of that[1] and the magazines. So I'll
have a look if I get a chance and see what the data indicates. BTW IIRC
materials like 'wood' and 'concrete' have ranges of material values that do
cover quite large ranges. Be interesting to refresh my memory on this when
I have a chance. :-)

Slainte,

Jim

[1] Cost a fortune and reads like the English is still in German. 8-] But
is packed with some interesting data and analysis. Recommended to anyone
with a serious interest in this topic who doesn't mind being faced with
some 'hard sums' maths. ;-

--
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

Powell wrote:

snip


For maximum effectiveness spikes should not be run
through any type of carpet interface (carpet/foam).
If you have high quality carpet, spikes just won't
penetrate the carpet/pad substrate.

If by pad you mean underlay, spikes I've used just do. Certainly helps a
lot with wobble, especially with small footprint floor standing speakers.

The tightly
woven jute backing and under pad is the problem.
The conical shape of spikes simply will not couple
to the sub-floor... and I mean tightly.

What do you mean by a sub-floor? Floor?!

Rob

In article ,
Rob wrote:
Powell wrote:

snip


For maximum effectiveness spikes should not be run
through any type of carpet interface (carpet/foam).
If you have high quality carpet, spikes just won't
penetrate the carpet/pad substrate.

If by pad you mean underlay, spikes I've used just do. Certainly helps a
lot with wobble, especially with small footprint floor standing speakers.

Indeed, I've just remembered that the pair of LS3/5A's I have on stands in
the dining room also have spikes - for the same reason as you mention. On
tall stands and wobble alarmingly or may move around if bumped into unless
spiked. They also penetrate though quite a thick carpet and underlay.

Maybe none of us have "high" enough "quality" carpet. Can't say as yet as
these are also words Powell has used without providing a measurable
definition. The phrase "vague and sweeping assertions" does come to mind.
Maybe "sweeping" is relevant for carpets, though... :-)

Slainte,

Jim

--
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

"Jim Lesurf" wrote

My speakers have four spikes beneath them which makes it a pain to
move the speakers even slightly as the length of at least one
spike has to be adjusted to make all four rest on/in the floor.
(The floor is solid - maybe concrete - and not wood.)

"concrete"... is a very good vibration sink compared to wood, for
example.

What size/shape/structure/type of "concrete" do you have in mind, and
what do you mean by "sink"? Can you point pun me at measurements to
support what you say?

In theory, all things being equal (concrete's mass will convert more
sound energy to heat more efficiently as compared to wood which tends to
resonate.

Afraid that reads like a rather muddled set of assertions to me. Which
"all
things" are you setting "equal"? What do you mean by "concrete's mass"? Do
you mean 'density', or what?

How does 'concrete' having 'mass' mean it disspates vibration more easily
than the same 'mass' of wood?

What about the question of coupling between the different mechanical
impedances which may mean that less energy transfers? etc, etc.

All solid structures have a tendency to 'resonate'. But since you still
say
nothing about the structral sizes and shapes, nor the internal wave
impedances, velocities, or dissipation factors, nor how the coupling
depends on many factors, your assertion isn't one you have actually
explained.

The spiked speaker act as a spring component (albeit a rather stiff one).
The potential positive effect of spikes is related to the speaker-floor
coupling this spring component causes.

The speaker-floor coupling is a (more or less damped) resonnant system.
Below the resonnance frequency, the speaker & floor acts as one solid unit.
If you have a rigid, heavy floor (concrete etc), you might experience clean
bass with maximum attack. Hi-fi bass at it's best? With a lively (wooden
etc.) floor, the floor - and maybe even the walls - may act as passive
transducers totally out of control. If you can feel the bass coming through
your feet or your chair (as opposed to hitting your stomach & chest) this is
probably what caused it. Hi-fi bass at it's worst!

Above the resonnance frequency, the speaker is practically decoupled from
the floor. Whether this causes "the tail wagging the dog" in an audible
sense depends on speaker mass, cone mass, speaker center of inertia and cone
location on speaker. In most cases this effect will be neglible. But if the
resonnance frequency is very low (say, 15 Hz) - and if the speaker is
lightweight (30-40 Lbs) - you may get compressed transient response,
particularly from the bass element.

What's now left is the region around the resonnance frequency. A lot of
unwanted things may happen here. The speaker-floor coupling will have a Q
value, determining how well-damped the resonnance is. Poor damping may cause
significant problem in this region - due to speaker vibration.

For a given speaker, the speaker-floor coupling (be it spikes, squash balls,
rubber wheels, MDF etc), defines the resonnant frequency and the Q value of
the coupling. Spikes will typically move the resonnant frequency up somwhere
in the midrange , and the system will have a relatively high Q-value. While
(in some cases) improving bass performance, this may create audible problems
in the midrange. Remove the spikes and you may replace midrange problems
with similar (but not neccessarily similar sounding) problems in the bass
region. You cannot move the resonnance frequency above audible range (20
kHz) - which is why you might have to compromise.

Another strategy is to move the resonnance down in frequency with silent
feet, rubber weels etc. With heavy speakers you can move the resonnance
frequency well below 20 Hz - out of audible range. In addition the bass
output will be as clean as you've ever heard, but you might be loosing some
attack due to the decoupling from the floor (or maybe you're just addicted
to "hi-fi bass"). Compromise here too? Maybe not.

Allthough the sonic effects of spikes may vary from speaker to speaker and
from room to room, they do move the resonnance of the speaker-floor combo up
in frequency. Sometimes it improves overall sound, sometimes it doesn't. But
the effects have a very natural explanation.



Many high end speaker manufactures like Wilson Audio, B&W,
Egglestonworks and others construct speaker cabinets out of synthetic
compounds, stone, or aluminum for this reason., for example. Of course
in practice it is more a complicated subject because of Q value effects.

Meausrements... yes, I have data. What is your specific question?

Provide the specific measurements (and how you did them) that back up the
specific assertions you make above. We could then decide if your views are
supported by measurements you (or others) have made, nor not.

Who is "we"? You don't speak for anyone but yourself, Lesurf.


Since my background is in science and engineering,

There are ZERO qualifications, not even a Drivers License,
for someone to call themselves a "Engineer". What kind of
formal education in engineering do you have...
undergraduate/graduate and in what field?


I do tend to prefer to base my own conclusions on being able
to assess measured evidence, and the details of how those
measurements were obtained.

I understand. I've run about 23 batches of tests, as I recall, several
years back. If I have time I'll post something.


Given that consumer audio is awash with 'technobabble' I tend to
place more reliance on that than on simply accepting assertions.

You enjoy intellectualizing but it would behoove you to get off your
penguin butt and do the work yourself.

In article , Powell
wrote:

"Jim Lesurf" wrote
[big snip of assertions and opinions]

Meausrements... yes, I have data. What is your specific question?

Provide the specific measurements (and how you did them) that back up
the specific assertions you make above. We could then decide if your
views are supported by measurements you (or others) have made, nor not.

Who is "we"?

This is usenet, and these postings are going to a number of groups. Chances
are you and I aren't the only people reading this. Surprised if you didn't
know this. Or is your question purely a debating tactic?

You don't speak for anyone but yourself, Lesurf.

Ah,you seem to have adopted the 'Go for the man, not the ball' debating
tactic. And employed the tone of 'Headmaster telling off the naughty
schoolboy who dared to ask impertinent questions'. :-)

....or as just a debating tactic to cover for not actually answering my
questions and providing the measurements you say you have. Is the idea
now to try and get a personal argument going to smokescreen that? :-)


Since my background is in science and engineering,

There are ZERO qualifications, not even a Drivers License, for someone
to call themselves a "Engineer". What kind of formal education in
engineering do you have... undergraduate/graduate and in what field?

Ah, yes. Looks like you do prefer "go for the man not the ball" instead of
dealing with the substance.

You seem to overlooked that you haven't yet provided any measurements or
details of how you obtained them. Lacking that, how could anyone else say
if a given background would be appropriate to judge what you did? And the
point of my "we" above was that once you 'publish' your data every/any
individual reading this could make up their own mind about your assertions
without having to take either me or you as an 'expert'.

I'm not bothered if you doubt I am 'qualified' or not. Nor if someone else
has doubts. In physical science and engineering, people decide on the
evidence, not on the basis of simply accepting that someone is 'qualified'
so must be right. I just wanted to see what evidence you could offer for
your assertions and claims.

BTW Note that you introduced "qualifications" as if they were a test of
some kind. Not me. Then snipped the explaination I gave for why I was
saying what I was. Although if you want to call me 'Lesurf' you could be
more accurate and call me 'Dr Lesurf' purely for the sake of form. :-)
Maybe even put letters like IEEE and AES somewhere after my name, I guess.
But I agree with you that 'Dr' in front of my name, etc, doesn't ensure I
could judge your measurements. Hence I don't normally use the 'Dr', etc, as
it seems irrelevant. Particularly when there are no presented measurements
to actually consider. :-)

I'm quite happy to leave others reading this to make up their own mind on
the basis of what you've said, and how you have responded. That should set
your mind at rest if you fear I might lack the required 'qualifications'
you would demand for anyone who dared to examine your measurements in a
critical manner. :-)


I do tend to prefer to base my own conclusions on being able to assess
measured evidence, and the details of how those measurements were
obtained.

I understand. I've run about 23 batches of tests, as I recall, several
years back. If I have time I'll post something.

Look forwards to it. :-) Please post the announcement in all the groups
this is going to if you wish everyone reading your assertions to be able to
make up their own minds and decide for themselves if your measurements
actually support what you have claimed.

Given that consumer audio is awash with 'technobabble' I tend to place
more reliance on that than on simply accepting assertions.

You enjoy intellectualizing but it would behoove you to get off your
penguin butt and do the work yourself.

Thanks for your help. Your response does help me make an interim assessment
of your assertions whilst I await any evidence you eventually produce.

Slainte,

Jim

--
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

Powell wrote:

Allthough the sonic effects of spikes may vary from speaker to
speaker and from room to room, they do move the resonnance of the
speaker-floor combo up in frequency. Sometimes it improves overall
sound, sometimes it doesn't. But the effects have a very natural
explanation.

Care to explain the mechanism that causes the resonant frequency to move up?


Given that consumer audio is awash with 'technobabble' I tend to
place more reliance on that than on simply accepting assertions.

You enjoy intellectualizing but it would behoove you to get off your
penguin butt and do the work yourself.

What makes you think he doesn't/hasn't? It's you that's making certain
claims about the effects of spikes, and the onus is on you to support those
claims with evidence. The fact that he's asking for evidence doesn't
preclude him having done his own research already.


--
Wally
www.wally.myby.co.uk
You're unique - just like everybody else.

In article , Wally
wrote:
Powell wrote:

Allthough the sonic effects of spikes may vary from speaker to speaker
and from room to room, they do move the resonnance of the
speaker-floor combo up in frequency. Sometimes it improves overall
sound, sometimes it doesn't. But the effects have a very natural
explanation.

Care to explain the mechanism that causes the resonant frequency to move
up?

FWIW I decided not to comment on the bulk of the items asserted most
recently as I didn't want to widen the issues. But a number of questions
like the above did occur to me. The problem is that with no measurements,
details of experimental arrangements, etc, it is often hard to assess the
assertions people make.


Given that consumer audio is awash with 'technobabble' I tend to
place more reliance on that than on simply accepting assertions.

You enjoy intellectualizing but it would behoove you to get off your
penguin butt and do the work yourself.

What makes you think he doesn't/hasn't? It's you that's making certain
claims about the effects of spikes, and the onus is on you to support
those claims with evidence. The fact that he's asking for evidence
doesn't preclude him having done his own research already.

Nor is it a requirement that someone must already have done their own
personal measurements to ask for the measurements someone else claims to
already have to support their assertions.

The point of the scientific approach is that anyone who wishes can make
their own decisions *based on the presented evidence*. Not on the basis
that they must accept that the person making the assertions is an
'authority' who must not be questioned or doubted. Access to the
measurements and details of how they were done allows anyone who wishes to
come to their own conclusions.

So for me the key point is the middle one made above. That Powell is making
a series of assertions and claiming to have 'measurements' to back them up.
As is the norm in physical science and engineering, this means we judge the
assertions by examination of the evidence. Up to the person making the
assertions to provide this. I see no reason at present to doubt he does
have 'measurements', but none of us can judge their value without seeing
them and knowing the details of how they were obtained. Hence my questions
to him.

I have noticed over they years that it is quite common on usenet (and
perhaps in audio in particular) for some people to react to being asked for
mere evidence or an explanation that can be tested on the basis of
estabilished physical science as if being asked was a 'personal attack'.
Hence responses using debating or other tactics like 'go for the man' for
daring to question the asserted 'wisdom'. To me that seems at best an
irrelevance, and at worst a smokescreen preventing each person from being
able to form their own conclusions on the basis of the *evidence*. I have
no real interest in debating games or personal arguments. So if no
measurements are forthcoming I am content to leave the matter here and
allow each person reading this thread to come to their own conclusions.

Slainte,

Jim

--
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

"Jim Lesurf" wrote in message
...
In article , Powell
wrote:

"Jim Lesurf" wrote
[big snip of assertions and opinions]

Meausrements... yes, I have data. What is your specific question?

Provide the specific measurements (and how you did them) that back up
the specific assertions you make above. We could then decide if your
views are supported by measurements you (or others) have made, nor not.

Who is "we"?

This is usenet, and these postings are going to a number of groups.
Chances
are you and I aren't the only people reading this. Surprised if you didn't
know this. Or is your question purely a debating tactic?

You don't speak for anyone but yourself, Lesurf.

Ah,you seem to have adopted the 'Go for the man, not the ball' debating
tactic. And employed the tone of 'Headmaster telling off the naughty
schoolboy who dared to ask impertinent questions'. :-)

...or as just a debating tactic to cover for not actually answering my
questions and providing the measurements you say you have. Is the idea
now to try and get a personal argument going to smokescreen that? :-)


Since my background is in science and engineering,

There are ZERO qualifications, not even a Drivers License, for someone
to call themselves a "Engineer". What kind of formal education in
engineering do you have... undergraduate/graduate and in what field?

Ah, yes. Looks like you do prefer "go for the man not the ball" instead of
dealing with the substance.

You seem to overlooked that you haven't yet provided any measurements or
details of how you obtained them. Lacking that, how could anyone else say
if a given background would be appropriate to judge what you did? And the
point of my "we" above was that once you 'publish' your data every/any
individual reading this could make up their own mind about your assertions
without having to take either me or you as an 'expert'.

I'm not bothered if you doubt I am 'qualified' or not. Nor if someone else
has doubts. In physical science and engineering, people decide on the
evidence, not on the basis of simply accepting that someone is 'qualified'
so must be right. I just wanted to see what evidence you could offer for
your assertions and claims.

BTW Note that you introduced "qualifications" as if they were a test of
some kind. Not me. Then snipped the explaination I gave for why I was
saying what I was. Although if you want to call me 'Lesurf' you could be
more accurate and call me 'Dr Lesurf' purely for the sake of form. :-)
Maybe even put letters like IEEE and AES somewhere after my name, I guess.
But I agree with you that 'Dr' in front of my name, etc, doesn't ensure I
could judge your measurements. Hence I don't normally use the 'Dr', etc,
as
it seems irrelevant. Particularly when there are no presented measurements
to actually consider. :-)

I'm quite happy to leave others reading this to make up their own mind on
the basis of what you've said, and how you have responded. That should set
your mind at rest if you fear I might lack the required 'qualifications'
you would demand for anyone who dared to examine your measurements in a
critical manner. :-)


I do tend to prefer to base my own conclusions on being able to assess
measured evidence, and the details of how those measurements were
obtained.

I understand. I've run about 23 batches of tests, as I recall, several
years back. If I have time I'll post something.

Look forwards to it. :-) Please post the announcement in all the groups
this is going to if you wish everyone reading your assertions to be able
to
make up their own minds and decide for themselves if your measurements
actually support what you have claimed.

Given that consumer audio is awash with 'technobabble' I tend to place
more reliance on that than on simply accepting assertions.

You enjoy intellectualizing but it would behoove you to get off your
penguin butt and do the work yourself.

Thanks for your help. Your response does help me make an interim
assessment
of your assertions whilst I await any evidence you eventually produce.

Slainte,

Jim

--
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

There are ZERO qualifications, not even a Drivers License, for someone
to call themselves a "Engineer". What kind of formal education in
engineering do you have... undergraduate/graduate and in what field?


Really? Would you care to explain that to my daughter, who gained her
degree in Mechanical Engineering from Coventry a few years ago? Or her
grandfather, who did the same degree (different Uni - I think Oxbridge, but
can't remember - it was pre-war) and among other things certificated the
Olympus engines fitted to Concorde but to the end of his days was happy to
describe himself as an "engineer"?

Zero qualifications? I don't think so.

Geoff MacK