[Laurence Payne[_2_]]

On Mon, 24 Aug 2009 16:49:28 +0100, "David Looser"
wrote:


At one time there was a fad for mounting speakers as far into room corners
as possible. My granddad, who was something of a "HiFi" enthusiast in the
1950s built a speaker cabinet which used the walls and floor as part of the
cabinet. I seem to remember that a barrow-load of sand was part of it as
well.

Yup. And it probably got very loud with only a few watts input. If
we were prepared to let our speakers take up rather more space,
speaker design (and amp. power) could be very different :-)

[Peter Larsen[_3_]]

James Harris wrote:

Any ideas?

Widening the net a little....

Spikes is a concept that seems woefully short of merit, while vibration
absorbers is known and described in the literature as efficient in terms of
reducing midrange coloration via secondary radiation from the floor.
Literature reference: accellerometer measuments made by Arne E. Jensen on
his 4433 and the floor they were located on and published in the danish
magazine High Fidelity around 1978 or so.

Poul Ladegaard took this a step further by demonstrating the additional
advantage in decoupling the (midrange) loudspeaker unit from the front
panel.

It would be most interestering if the spikists have similar accellorometer
measurements that document the advantage of spikes.

James

Kind regards

Peter Larsen

[Laurence Payne[_2_]]

On Mon, 24 Aug 2009 17:07:49 +0100, "Keith G"
wrote:

(I remember once I got someone to listen with his eyes shut while I slowly
rotated one speaker until it was facing the wall - he had no idea what was
going on and said the sound was unaffected throughout!! ;-)

Yes, the Critical Distance for a given room/speaker combination is
often closer than you think! In PA applications sometimes it's
practically impossible to place the audience inside it.

Where's your hi-fi listening "sweet spot" in relation to the CD? In
any given room, the same for all speakers or not? When recording, I'm
used to monitoring well inside, but checking a mix from WAY outside -
like in the next room with the door shut!

[Scott Dorsey]

Laurence Payne wrote:
On 24 Aug 2009 10:52:05 -0400, (Scott Dorsey) wrote:

The sort of reasoning that puts spikes on speakers but doesn't really
know why. Some say it's to "couple". Others to "decouple". What do
you think they're for?

You can do either... you can couple the speaker to a huge mass, or you can
decouple it from all (possibly resonant) masses. Either method works, and
you can measure whether it's working or not (or you can just put your hand
on the floor and feel if it's vibrating).

Reading at face value, that reply states that spikes either couple or
decouple the speaker from what it's standing on. Depending on which
you WANTED them to do.

This can't be right. What DID you mean?

It depends on what you do with the spikes and where you place them. The
original intention was to couple the speaker through a carpet to a solid
floor, so the floor and the speaker move as a system. But they can also be
used with a flexible material like a rubber pad to decouple the speakers from
the floor.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

GregS wrote:
Another thing, if the floor is vibrating from the air vibrations, and
the speaker is still, the floor will make the speaker shake.

Yes.
But if the floor is vibrating from the air vibrations, you have a more
serious problem than that. A common one, but serious nevertheless.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Laurence Payne[_2_]]

On 24 Aug 2009 12:33:37 -0400, (Scott Dorsey) wrote:

Reading at face value, that reply states that spikes either couple or
decouple the speaker from what it's standing on. Depending on which
you WANTED them to do.

This can't be right. What DID you mean?

It depends on what you do with the spikes and where you place them. The
original intention was to couple the speaker through a carpet to a solid
floor, so the floor and the speaker move as a system. But they can also be
used with a flexible material like a rubber pad to decouple the speakers from
the floor.

In the second case, why spikes? Why not just the rubber pad?

[Scott Dorsey]

David Looser wrote:
"Laurence Payne" wrote in message

My practical experience of large speakers - some much larger than
anything found in a domestic setup - is that they generally sound MUCH
better mounted at least a small distance away from any flat surface,
wall or floor.

At one time there was a fad for mounting speakers as far into room corners
as possible. My granddad, who was something of a "HiFi" enthusiast in the
1950s built a speaker cabinet which used the walls and floor as part of the
cabinet. I seem to remember that a barrow-load of sand was part of it as
well.

The corner horn had some advantages: first of all it meant that you could
take advantage of the edge effects of the corner to provide increased bass
response, and secondly that bass boost was predictable because everyone would
put the speaker in the same place in every room, rather than have it an
unknown distance from the rear and side walls.

It made sense back in the fifties when loaded horns were essential for high
efficiency at low frequencies, in an era of low amplifier power. Back then,
systems were mono and so the inability to place the speaker for good imaging
was a non-issue.

When stereo came in, corner horns went away.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article ,
Laurence Payne wrote:
On 24 Aug 2009 12:33:37 -0400, (Scott Dorsey) wrote:

Reading at face value, that reply states that spikes either couple or
decouple the speaker from what it's standing on. Depending on which
you WANTED them to do.

This can't be right. What DID you mean?

It depends on what you do with the spikes and where you place them. The
original intention was to couple the speaker through a carpet to a solid
floor, so the floor and the speaker move as a system. But they can also be
used with a flexible material like a rubber pad to decouple the speakers from
the floor.

In the second case, why spikes? Why not just the rubber pad?

You want to minimize the area of contact with the pad. Plenty of more
efficient ways to do that than spikes, mind you, but spikes are usually
what people have handy.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[David Looser]

"Scott Dorsey" wrote in message
...
David Looser wrote:
"Laurence Payne" wrote in message

My practical experience of large speakers - some much larger than
anything found in a domestic setup - is that they generally sound MUCH
better mounted at least a small distance away from any flat surface,
wall or floor.

At one time there was a fad for mounting speakers as far into room corners
as possible. My granddad, who was something of a "HiFi" enthusiast in the
1950s built a speaker cabinet which used the walls and floor as part of
the
cabinet. I seem to remember that a barrow-load of sand was part of it as
well.

The corner horn had some advantages: first of all it meant that you could
take advantage of the edge effects of the corner to provide increased bass
response, and secondly that bass boost was predictable because everyone
would
put the speaker in the same place in every room, rather than have it an
unknown distance from the rear and side walls.

It made sense back in the fifties when loaded horns were essential for
high
efficiency at low frequencies, in an era of low amplifier power. Back
then,
systems were mono and so the inability to place the speaker for good
imaging
was a non-issue.

When stereo came in, corner horns went away.

It wasn't a horn, it was a bass-reflex.

David.

[Scott Dorsey]

David Looser wrote:

When stereo came in, corner horns went away.

It wasn't a horn, it was a bass-reflex.

There's a lot less benefit in putting a bass-reflex design in a corner,
but you do still get that edge effect and the matter of consistency.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[David Looser]

"Scott Dorsey" wrote in message
...
David Looser wrote:

When stereo came in, corner horns went away.

It wasn't a horn, it was a bass-reflex.

There's a lot less benefit in putting a bass-reflex design in a corner,
but you do still get that edge effect and the matter of consistency.

I don't buy this "consistency" notion. There are still far too many
diferences: room size, furnishings and building construction. And that's
before we think about differences in the speakers themselves: driver types
and sizes, materials used, construction techniques etc.

David.

[Paul P[_3_]]

Scott Dorsey wrote:

Laurence Payne wrote:

In the second case, why spikes? Why not just the rubber pad?

You want to minimize the area of contact with the pad. Plenty of more
efficient ways to do that than spikes, mind you, but spikes are usually
what people have handy.

I've thought that the minimal contact area was important but the
smaller you go the higher the pressure so do things remain the
same ?

Paul P

[Peter Larsen[_3_]]

Scott Dorsey wrote:

David Looser wrote:

When stereo came in, corner horns went away.

It wasn't a horn, it was a bass-reflex.

There's a lot less benefit in putting a bass-reflex design in a
corner, but you do still get that edge effect and the matter of
consistency.

Ime it is about the same 8 dB and they are worth having because the boost
from a corner is the smoothest available, also it fits a traditional tone
control very well and it is easy to get some degree of perceived
linearisation. With my current 4 way it is just a matter of overall bass
unit(s) drive level to get a reasonable tonal balance.

--scott

Kind regards

Peter Larsen

[Ian Iveson]

James 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.)


Anyone heard of a kit to convert four spikes to three? It
would have
to fit beneath the existing arrangement as I don't want
to modify the
speakers (which are Dynaudio Audience 62 floorstanders).


I'm thinking of something like a heavy duty plate with
four solid
fittings above and three below. I suppose an alteration
to the sound
is inevitable but would avoid scrap the idea if it has
too much
effect.


An alternative is to put paving slabs on top of the
carpet beneath the
speakers. They should be heavy enough to not move and
also present a
more uniform surface for the speakers though even that
would not be
perfect. The slight problem here is the slabs sold by the
local stores
are fairly lightweight.

Why don't chairs have three legs?

Tractors had three legs and they fell over easily. Maybe
they still do.

If you must use a tripod, put the single leg at the back,
otherwise the speaker will tip over if you brake mid-corner.
You can race a Morgan, but not a Reliant, unless you're
daft. At least when it falls over the chances are that it'll
be driver-side up, so a cone won't get spiked by the corner
of the coffee table.

If you had a four-to-three adaptor platform, then every time
you moved a speaker, you would need to lift it off its
platform, then move the platform, then lift the speaker back
onto it. That would surely take just as much time and effort
as adjusting a leg?

A flat stone could be more or less wobbly than four
imperfectly adjusted legs unless it's a lot wider, in which
case it might still be a bit wobbly and someone's bound to
trip and/or stub a toe on it, to boot, especially if you
keep moving it around. Anyway, if it's big and heavy then
it's hard to move, so how's that easier than adjusting a leg
or two?

If your floor is lumpy and you use a tripod, the chances are
that your speakers won't be upright.

You should put up with the need for adjustment.
Manufacturers of speakers (and cars) have generally found
the best compromise.

OTOH, perhaps an adaptor platform would make a plausible
audiophool accessory?

Ian

[Scott Dorsey]

David Looser wrote:
"Scott Dorsey" wrote in message
David Looser wrote:

When stereo came in, corner horns went away.

It wasn't a horn, it was a bass-reflex.

There's a lot less benefit in putting a bass-reflex design in a corner,
but you do still get that edge effect and the matter of consistency.

I don't buy this "consistency" notion. There are still far too many
diferences: room size, furnishings and building construction. And that's
before we think about differences in the speakers themselves: driver types
and sizes, materials used, construction techniques etc.

Yup, that's true, but the number one thing that determines the low end
response (outside of the loudspeaker itself) is the boundary effect.
The corner horn controls that.

Now, things like standing waves in the room are still very, very significant
and corner placement doesn't do anything to reduce that; if anything it can
actually make some modes worse.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Dave Plowman (News)]

In article ,
Keith G wrote:
Since it's impossible to make a totally rigid speaker cabinet some
makers take into account any 'output' from the cabinet itself. Think
the first to do this was the Spendor BC1. Which was designed to be
mounted on an open stand about 9" high. Adding mass to the cabinet -
like putting books on top - would negate the design theory.


The Rogers 'BBC Studio Monitors' I had here a while back were
'thinwall/resonating' types and sounded very good indeed,

Probably the same family as the BC1 - from an original BBC design study.

apart from the
rasping bass unit I couldn't cure - without spending a lot of money and
maybe changing the speakers characteristics too much, in any case....

I suppose you tried inverting the driver?

--
*Few women admit their age; fewer men act it.

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

[Arny Krueger]

"Scott Dorsey" wrote in message

Laurence Payne wrote:
On 24 Aug 2009 10:52:05 -0400, (Scott
Dorsey) wrote:

The sort of reasoning that puts spikes on speakers but
doesn't really know why. Some say it's to "couple".
Others to "decouple". What do you think they're for?

You can do either... you can couple the speaker to a
huge mass, or you can decouple it from all (possibly
resonant) masses. Either method works, and you can
measure whether it's working or not (or you can just
put your hand on the floor and feel if it's vibrating).

Reading at face value, that reply states that spikes
either couple or decouple the speaker from what it's
standing on. Depending on which you WANTED them to do.

This can't be right. What DID you mean?

It depends on what you do with the spikes and where you
place them. The original intention was to couple the
speaker through a carpet to a solid floor, so the floor
and the speaker move as a system. But they can also be
used with a flexible material like a rubber pad to
decouple the speakers from the floor. --scott

I've ever heard spike claimed to be the mechanical equivalent of diodes...
....but audiophools say a lot of crazy things.

Driver moving mass is usually much less than 100 grams, but can be a 400
grams for some low-efficiency subwoofers. If the woofer is attached to a
substantial cabinet, the actual motion of the speaker enclosure due to cone
motion will be highly damped by simple mass loading to the point where the
energy thus radiated is trivial.

In general, the vibrations radiated by the cone are by far the most
important effect of the speaker, which is according to the basic design. ;-)

The proof of the pudding is to suspend the speaker in the almost same
location by means of fishline suspended from the ceiling which gives a very
strong decoupling effect. In actual tests, the speaker sounds the same.

[Keith G[_2_]]

"Laurence Payne" wrote in message
...
On Mon, 24 Aug 2009 16:49:28 +0100, "David Looser"
wrote:


At one time there was a fad for mounting speakers as far into room corners
as possible. My granddad, who was something of a "HiFi" enthusiast in the
1950s built a speaker cabinet which used the walls and floor as part of
the
cabinet. I seem to remember that a barrow-load of sand was part of it as
well.

Yup. And it probably got very loud with only a few watts input. If
we were prepared to let our speakers take up rather more space,
speaker design (and amp. power) could be very different :-)


Still is for a lot of people who prefer low power amp+efficient speakers to
*powerhouse* arcwelder+ironing board setups....

[Keith G[_2_]]

"Dave Plowman (News)" wrote in message
...
In article ,
Keith G wrote:
Since it's impossible to make a totally rigid speaker cabinet some
makers take into account any 'output' from the cabinet itself. Think
the first to do this was the Spendor BC1. Which was designed to be
mounted on an open stand about 9" high. Adding mass to the cabinet -
like putting books on top - would negate the design theory.


The Rogers 'BBC Studio Monitors' I had here a while back were
'thinwall/resonating' types and sounded very good indeed,

Probably the same family as the BC1 - from an original BBC design study.

apart from the
rasping bass unit I couldn't cure - without spending a lot of money and
maybe changing the speakers characteristics too much, in any case....

I suppose you tried inverting the driver?


Sure - first port of call after turning the whole box upside down; then I
tried all sorts of fiddling about before I spoke to DK Loudspeakers:

http://www.moirac.adsl24.co.uk/showntell/DSCN1476.JPG

[Keith G[_2_]]

"Laurence Payne" wrote in message
...
On Mon, 24 Aug 2009 17:07:49 +0100, "Keith G"
wrote:

(I remember once I got someone to listen with his eyes shut while I slowly
rotated one speaker until it was facing the wall - he had no idea what was
going on and said the sound was unaffected throughout!! ;-)

Yes, the Critical Distance for a given room/speaker combination is
often closer than you think! In PA applications sometimes it's
practically impossible to place the audience inside it.

Where's your hi-fi listening "sweet spot" in relation to the CD? In
any given room, the same for all speakers or not? When recording, I'm
used to monitoring well inside, but checking a mix from WAY outside -
like in the next room with the door shut!


In normal use I don't go for all this 'sweet spot' malarkey - I listen to
most of my music through the doorway from the next room when I'm not
listening to the setup on this computer! Anyway, a little while ago I was
prompted to make a couple of (mono) microphone recordings of the SET/Lothers
with my toyshop ribbon (haven't done it for ages) thus:

http://www.moirac.adsl24.co.uk/shown...ibbonSetup.jpg

(Note the dressing gown hanging behind it to soak up the 'backdraft'...)

Here's a couple of very dirty extracts, complete with hiss, hum, the 'needle
down' bang and even the sound of me closing the door, to give you an
approximate *recorded* idea of what I like soundwise:

http://www.moirac.adsl24.co.uk/shown...phtExtract.mp3

http://www.moirac.adsl24.co.uk/shown...htExtract2.mp3

[UnsteadyKen[_4_]]

In article ,
says...
Here's a quick snap:

http://www.moirac.adsl24.co.uk/showntell/Triangular.jpg

I see we shared the same taste in upmarket equipment racks and
meticulous wiring practice.

[Laurence Payne[_2_]]

On Mon, 24 Aug 2009 21:53:42 +0100, "Keith G"
wrote:

In normal use I don't go for all this 'sweet spot' malarkey - I listen to
most of my music through the doorway from the next room when I'm not
listening to the setup on this computer!

Oh sure, me too. Unless I'm working, I'm listening to the music not
the equipment. Or just enjoying a pleasant background noise.

But just now and again the BBC pump out something good and I fancy
wallowing in a bit of stereo image. So I need to know where the sweet
spot IS :-)

[UnsteadyKen[_4_]]

oopths

http://www.btinternet.com/~unsteadyken/mycrap.JPG

[Dave Plowman (News)]

In article ,
Keith G wrote:
The Rogers 'BBC Studio Monitors' I had here a while back were
'thinwall/resonating' types and sounded very good indeed,

Probably the same family as the BC1 - from an original BBC design
study.

apart from the rasping bass unit I couldn't cure - without spending a
lot of money and maybe changing the speakers characteristics too
much, in any case....

I suppose you tried inverting the driver?


Sure - first port of call after turning the whole box upside down; then
I tried all sorts of fiddling about before I spoke to DK Loudspeakers:

http://www.moirac.adsl24.co.uk/showntell/DSCN1476.JPG

If it was like the original BC1, the actual power handling was very low.
About 25 watts. It was designed by the BBC for use where high monitor
levels wouldn't be needed - and attempts at that wouldn't work as the BBC
ones had built in amps. Spendor very soon upgraded the bass units to
handle 50 watts.

--
*Gaffer tape - The Force, light and dark sides - holds the universe together*

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

[Meindert Sprang]

"UnsteadyKen" wrote in message
...




oopths

http://www.btinternet.com/~unsteadyken/mycrap.JPG

The brandname "IKEA" springs to mind....

Meindert

[Dave Plowman (News)]

In article ,
Meindert Sprang wrote:
"UnsteadyKen" wrote in message
...




oopths

http://www.btinternet.com/~unsteadyken/mycrap.JPG

The brandname "IKEA" springs to mind....

Some judicious use of trunking wouldn't go amiss. ;-)

--
*How do they get the deer to cross at that yellow road sign?

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

[Laurence Payne[_2_]]

On Tue, 25 Aug 2009 09:41:51 +0200, "Meindert Sprang"
wrote:

http://www.btinternet.com/~unsteadyken/mycrap.JPG

The brandname "IKEA" springs to mind....

Actually, one of those cheap Ikea wooden shelving units could probably
do a neater job. And wood's always nicer to look at. Or are those
"magic" shelves?

[Meindert Sprang]

"Laurence Payne" wrote in message
...
On Tue, 25 Aug 2009 09:41:51 +0200, "Meindert Sprang"
wrote:

http://www.btinternet.com/~unsteadyken/mycrap.JPG

The brandname "IKEA" springs to mind....

Actually, one of those cheap Ikea wooden shelving units could probably
do a neater job. And wood's always nicer to look at. Or are those
"magic" shelves?

Yeah, probably plated with non-magnetostrictive chrome...

Meindert

[UnsteadyKen[_4_]]

Dave Plowman (News) says...

Some judicious use of trunking wouldn't go amiss. ;-)

I tried that and cable tidies and ending up pulling my hair out when I
changed anything.

It photographs worse than it looks, sort of. We have so many sources
now, bring back the good old days. Connect up the turntable, tuner and
cassette deck and wonder what on earth the Aux socket could be used for.
Now I have 4 switch boxes.

--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/

[UnsteadyKen[_4_]]

Laurence Payne says...

Actually, one of those cheap Ikea wooden shelving units could probably
do a neater job. And wood's always nicer to look at. Or are those
"magic" shelves?

Ikea! Heavens man, do you think I've won the lottery?

Economy before neatness is my motto.
They are unbranded flat pack kitchen racks from my usual audiophile
supplier
http://www.tjmorris.co.uk/
"magic" for the price 12 quid each, sturdy, adjustable shelf spacing and
lightweight.


--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/

[GregS[_3_]]

In article , "Meindert Sprang" wrote:
"UnsteadyKen" wrote in message
...




oopths

http://www.btinternet.com/~unsteadyken/mycrap.JPG

The brandname "IKEA" springs to mind....


Hey, I got one of those. Its really nice. I had a 31 inch crt tv on it.
Heavy !!

greg

[Powell]

"James Harris" 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.

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


Anyone heard of a kit to convert four spikes to three?

Some speaker manufactures use only three spikes. Two
in the front and one in the back. This makes adjusting
tweeter face rake adjustments much easier too.


It would have to fit beneath the existing arrangement as I don't
want to modify the speakers (which are Dynaudio Audience
62 floorstanders).

Spike sources, check out:
http://www.madisound.com/catalog/ind...?cPath=404_121
http://www.musicdirect.com/category/49


Quality casters make a good alternative (measured
reduction in cabinet vibration) to speaker spikes, IME.
They also give you the ability to move the speakers
about freely.


I'm thinking of something like a heavy duty plate with four solid
fittings above and three below. I suppose an alteration to the sound
is inevitable but would avoid scrap the idea if it has too much
effect.


An alternative is to put paving slabs on top of the carpet beneath the
speakers. They should be heavy enough to not move and also present a
more uniform surface for the speakers though even that would not be
perfect. The slight problem here is the slabs sold by the local stores
are fairly lightweight.

This is the least desirable of the alternatives you've site so far.

Oct, 2000 , TAS - What's Wrong With Speakers
by R.E. Greene

"But as soon as a speaker gets an input signal, it
starts doing things it shouldn't and starts making
noise, not just the music it should be making. Cones
and surrounds flexing, mechanical structures
vibrating, cabinets flexing in unpredicted and
unpredictable ways, air flowing turbulently,
electrostatic diaphragms vibrating chaotically
on the scale of small areas even if they are moving
regularly on a large scale, such sources of noise
are everywhere."

"How much noise are we talking about here?
A lot, a whole lot by the standards of noise
levels in electronics and recording systems.
Speaker noise appears only 20 to 30 dB down
from signal in some cases, and even the
cleanest speakers I know do not get the noise
down much more than 55 dB or so."

[Jim Lesurf[_3_]]

In article , Powell
wrote:

"James Harris" 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?

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

"Work" means?...

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?

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

[Wally]

Keith G wrote:

Here's a couple of very dirty extracts, complete with hiss, hum, the
'needle down' bang and even the sound of me closing the door, to give
you an approximate *recorded* idea of what I like soundwise:

http://www.moirac.adsl24.co.uk/shown...phtExtract.mp3

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


--
Wally
www.wally.myby.co.uk
Stress: You wake up screaming and realise you haven't fallen asleep yet.

[Keith G[_2_]]

"Dave Plowman (News)" wrote in message
...
In article ,
Keith G wrote:
The Rogers 'BBC Studio Monitors' I had here a while back were
'thinwall/resonating' types and sounded very good indeed,

Probably the same family as the BC1 - from an original BBC design
study.

apart from the rasping bass unit I couldn't cure - without spending a
lot of money and maybe changing the speakers characteristics too
much, in any case....

I suppose you tried inverting the driver?


Sure - first port of call after turning the whole box upside down; then
I tried all sorts of fiddling about before I spoke to DK Loudspeakers:

http://www.moirac.adsl24.co.uk/showntell/DSCN1476.JPG

If it was like the original BC1, the actual power handling was very low.
About 25 watts.


Yes, exactly so:

http://www.moirac.adsl24.co.uk/shown...ogersLabel.JPG

[Powell]

"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. 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?


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).
If you have high quality carpet, spikes just won't
penetrate the carpet/pad substrate. 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. While it might
appear (feel) to you that your spikes are firmly in
they are still supported by the carper/pad. Sound
pressure measurements and auditioning indicate
only a poor improvement in fidelity if used in this way.


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.

[Keith G[_2_]]

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

Here's a couple of very dirty extracts, complete with hiss, hum, the
'needle down' bang and even the sound of me closing the door, to give
you an approximate *recorded* idea of what I like soundwise:

http://www.moirac.adsl24.co.uk/shown...phtExtract.mp3

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


Played, apparently, by the eponymous Rachel Grimes on a 1985 Zuckerman
French double-manual harpsichord. You can buy a kit and build one yourself
if you're up to it:

http://zhi.net/instr/FR63ZHI-K.shtml

:-)

Second extract (if I've got it right - I just plonked the needle down here
and there and strung a selection together in one go) is 'Mysterious
Disappearance Of Louis LePrince'...(??)

[Keith G[_2_]]

"UnsteadyKen" wrote in message
m...
In article ,
says...
Here's a quick snap:

http://www.moirac.adsl24.co.uk/showntell/Triangular.jpg

I see we shared the same taste in upmarket equipment racks and
meticulous wiring practice.





:-)

I've got a number of these racks - they were cheap as chips from Argos and
they're very strong!

(They figure in every shot of a kitchen I've seen lately and I've even seen
them posing as 'fixtures' in a submarine in some tossy film!!)

[Eiron]

Powell wrote:

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. 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.

You don't think that spikes will penetrate Jute? But that doesn't mean it wouldn't be fun trying.
Anyway, you are wrong. I just tried pushing a Tannoy spike through a piece of decent carpet
and underlay into my finger. It didn't take much force at all.

--
Eiron.

[Wally]

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.


Played, apparently, by the eponymous Rachel Grimes on a 1985 Zuckerman
French double-manual harpsichord. You can buy a kit and build one
yourself if you're up to it:

http://zhi.net/instr/FR63ZHI-K.shtml

:-)

Er, no.

Wouldn't mind a shot of one, though. The German double manual in the for
sale (or sold) section appeals to me more - not keen on the mega-ornate
styling.


--
Wally
www.wally.myby.co.uk
Things are always clearer in the cold, post-upload light.