Improving loudspeaker crossovers (SBL's)
 

"Bob Latham" wrote in message
...
In article ,
Serge Auckland wrote:
"Jim Lesurf" wrote in message

IIUC Some loudspeakers use a large capacitor in series with the LF
unit to alter the low frequency behaviour and interaction with the
cabinet effects. I think KEF did this with various speakers, but I
don't know how widespread the practice may be.


I haven't come across this at all, so I don't think the practice can
have been very widespread. Of course, before split power supplies were
common, solid-state power amps had a large capacitor in series with the
output, but that was for DC blocking reasons. I can't imagine why a
loudspeaker manufacturer would deliberately roll off the extreme LF,
unless it was for power-handling reasons at the time when the main
source was LPs and consequently there could be a lot of subsonic energy
due to warps and the like.

KEF did do this with models 101,103 and 105 and probably others. IIRC they
referred to it as a bass loading technique. Surprisingly, the implication
was that it increased the low frequency extension though I don't
understand the mechanism unless there was some resonance going on somehow.

Cheers,

Bob.

--
Bob Latham
Stourbridge, West Midlands

Thanks for that. I used to have a pair of 105s, and very much liked the
101s (much better than LS3/5A, I thought) and 103s, so KEF must have done
something right. I can't understand either how a series capacitance would
increase LF extension except, as you say, by some sort of resonance, perhaps
with the L equivalent component of the enclosure resonance. These KEF
'speakers were all sealed boxes, so there would be a resonance between the
air volume and cone suspension, and cone mass. Clever though!

S.


--
http://audiopages.googlepages.com

Improving loudspeaker crossovers (SBL's)
 

Serge Auckland wrote:
"Bob Latham" wrote in message
...
In article ,
Serge Auckland wrote:
"Jim Lesurf" wrote in message
IIUC Some loudspeakers use a large capacitor in series with the LF
unit to alter the low frequency behaviour and interaction with the
cabinet effects. I think KEF did this with various speakers, but I
don't know how widespread the practice may be.

I haven't come across this at all, so I don't think the practice can
have been very widespread. Of course, before split power supplies were
common, solid-state power amps had a large capacitor in series with the
output, but that was for DC blocking reasons. I can't imagine why a
loudspeaker manufacturer would deliberately roll off the extreme LF,
unless it was for power-handling reasons at the time when the main
source was LPs and consequently there could be a lot of subsonic energy
due to warps and the like.
KEF did do this with models 101,103 and 105 and probably others. IIRC they
referred to it as a bass loading technique. Surprisingly, the implication
was that it increased the low frequency extension though I don't
understand the mechanism unless there was some resonance going on somehow.

Cheers,

Bob.

--
Bob Latham
Stourbridge, West Midlands

Thanks for that. I used to have a pair of 105s, and very much liked the
101s (much better than LS3/5A, I thought) and 103s, so KEF must have done
something right. I can't understand either how a series capacitance would
increase LF extension except, as you say, by some sort of resonance, perhaps
with the L equivalent component of the enclosure resonance. These KEF
'speakers were all sealed boxes, so there would be a resonance between the
air volume and cone suspension, and cone mass. Clever though!

A high-Q bass resonance and a series capacitor would give some extra
bass extension but a higher order rolloff, compared to a properly sized,
i.e. larger, box.

--
Eiron.

Improving loudspeaker crossovers (SBL's)
 

"Rob" wrote in message


Serge Auckland wrote:

"Stevie Boy" wrote in message
...

snip leaving rigid definition part

Neutrality: Where a sound is reproduced as accurately
as possible without emphasis of any frequency.
In other words as life like as possible.

The two statements are not synonymous. Lack of emphasis
of any frequency means a flat frequency response, with
no sharp peaks or troughs, especially peaks. "As life
like as possible" implies not only a flat response, but
also low distortion and accurate dispersion
characteristics which, when the room acoustics are
included, result in an accurate representation of the
recorded event. The closest approach to the original
sound anyone?

This ignores a fact of life. The phrase "the origional sound" as applied to
recordings is an oxymoron. There is not just one origional sound, but an
infinite number of them. The myth of "the origional sound" is probably
symptomatic of that apparently large body of self-proclaimed experts whose
music listening experiences extend only to recordings. Anybody who has been
to a real live performance should have quickly noticed that sound quality
changes as one changes one's listening position.

In contrast, there is a valid usage of "the origional sound", as applied to
audio components such as amplifiers and recorders. Anything that has a
well-defined input and output, such as an electrical signal or a collection
of them, can be tested for faithfulness to "the original sound".

And 'an accurate rendition' of an 'original' need not
represent 'lifelike'.

I might be lost. If the accurate rendition is not lifelike (whatever *that*
means) then the original is not lifelike. Is it an equipment fault to
present a not-lifelike recording so that it is not perceived as being
lifelike? I think not. I should add that the process of enhancing a
recording that is not lifelike so that it is perceived as being lifelike is
a delicate art - one that is often impossible to execute. The quaint notion
that the sonic imperfections of an amplifier or record playback systems
could perform this trick of sonic legerdemain with any number of recordings
requires considerable suspension of disbelief.

If someone thinks an oboe sounds
more like an oboe with certain things added or taken away
from the original recorded sound (as opposed to the
performance), is that not more lifelike, and hence
neutral?

Good point. More likely, someone has a remembered experience of listening to
an oboe (more likely a recording of an oboe) somehow imprinted on their
brain. Relevant facts notwithstanding, anything that evokes a similar
emotional response is perceived as being consistent with the reference.

Bass weight: A stronger representation of the lows as
if it were a larger speaker.

As if speaker size was any sort of reliable indicator of bass performance.

How does this differ from extention?

Well, the phrase bass extension does make some sense, but as defined, "Bass
weight" makes no sense at all. So, they must be different. ;-)

Perhaps it does mean extension, although not necessarily
linearly.

What does linearly mean? Does it mean flat response or does it mean absence
of nonlinear distortion?

Imaging: placing voices & instruments at a point in
space.

Hard to measure, other than in terms of accuracy of other parameters.
Therefore, "soundstaging" is whatever people want it to be.

Soundstaging: How a performance fills the room, does
the sound feel it is in the room (if so does it fill
the whole room or sound as if it is confined to within
the speaker listening positions), confined towards the
speakers or eminating from the speakers!

This is primarily a function of the room, together with
the dispersion characteristics of the loudspeakers.

It could be a synonym for imaging. It should be synonym for imaging, but
proliferating the terminology is a common tactic for making nonsense to make
sense.

Room a big factor no doubt, but often not practical to
remedy. I do find that valve amplification and a vinyl
source create (recreate?!) a sense of space, making sound
more like music. Just thought I'd mention it ;-)

Smiley = joke. yes, the idea that the random corruptions of the audio signal
associated with modern tubed gear and any vinyl playback equipment would
make things categorically sound better is indeed a joke.

Improving loudspeaker crossovers (SBL's)
 

In article , Serge Auckland
scribeth thus
"tony sayer" wrote in message
...
Of course, the phrase "too dead" is a subjective one, and I agree with
toy
in that I prefer to listen to music in a room that tends toward the "dead"
rather than "live". I've never got on terribly well with the LEDE concept
(Live End Dead End) for listening rooms, I've always preferred a room
that
tends towards "dead" but one can still carry on normal conversation, and
has
a "normal" feel. What that means in actual RT and the frequency
distribution
of that RT I don't know, as I haven't measured many rooms. The IEC
standard
listening rooms I've been in have sounded "right", as have the radio
studios
built to the old



IBA Code of Practice.

Is that online anywhere?...

--
Tony Sayer


Not that I know of. I have a partial set of the IBA Technical Review
booklets. Book 2 has the CoP for TV and ILR studios.

If anyone's interested, I can scan the relevant Radio Studio pages and post
them


Be interesting .. but only when U have the time to do it!....
S.



--
Tony Sayer

Improving loudspeaker crossovers (SBL's)
 

"Arny Krueger" wrote



Smiley = joke. yes, the idea that the random corruptions of the audio
signal associated with modern tubed gear and any vinyl playback equipment
would make things categorically sound better is indeed a joke.


Yet, that they most categorically *do* is one of the Great Mysteries Of The
Modern Age....

:-)

Improving loudspeaker crossovers (SBL's)
 

Keith G wrote:

"Arny Krueger" wrote

Smiley = joke. yes, the idea that the random corruptions of the audio
signal associated with modern tubed gear and any vinyl playback equipment
would make things categorically sound better is indeed a joke.

Yet, that they most categorically *do* is one of the Great Mysteries Of The
Modern Age....

In your mind they do, it's one of the Great Mysteries Of The Stone Age....

Seriously, tube 'enhancement' doesn't work for everything by a long way.

Graham

Improving loudspeaker crossovers (SBL's)
 

"Eeyore" wrote in message
...


Keith G wrote:

"Arny Krueger" wrote

Smiley = joke. yes, the idea that the random corruptions of the audio
signal associated with modern tubed gear and any vinyl playback
equipment
would make things categorically sound better is indeed a joke.

Yet, that they most categorically *do* is one of the Great Mysteries Of
The
Modern Age....

In your mind they do, it's one of the Great Mysteries Of The Stone
Age....



Are you another one *in denial*?

In case you are not aware, you can very easily buy a *brand spanking new*
valve amp, record player and LPs to play on them....



Seriously, tube 'enhancement' doesn't work for everything by a long way.


I don't see valves as 'enhancement' myself, but accepting that you do, name
one thing they don't work for - in a strictly audio context, of course...

Improving loudspeaker crossovers (SBL's)
 

Keith G wrote:

"Eeyore" wrote
Keith G wrote:
"Arny Krueger" wrote

Smiley = joke. yes, the idea that the random corruptions of the audio
signal associated with modern tubed gear and any vinyl playback
equipment would make things categorically sound better is indeed a joke.


Yet, that they most categorically *do* is one of the Great Mysteries Of
The Modern Age....

In your mind they do, it's one of the Great Mysteries Of The Stone
Age....

Are you another one *in denial*?

In case you are not aware, you can very easily buy a *brand spanking new*
valve amp, record player and LPs to play on them....

I'd rather avoid the distortion of the valves and the sheer inconvenience of
the LPs never mind the scratches, pops, rumble, hiss, sloppy frequency response
etc.

I do have a Garrard 401 and Ortofon arm btw. It hasn't seen serious use in
around 20 years.


Seriously, tube 'enhancement' doesn't work for everything by a long way.

I don't see valves as 'enhancement' myself,

They're used as a 'special effect' mostly in music recording.


but accepting that you do, name
one thing they don't work for - in a strictly audio context, of course...

Any form of highly detailed music. They 'muzz it up'.

Graham

Improving loudspeaker crossovers (SBL's)
 

"Eeyore" wrote in message
...


Keith G wrote:

"Eeyore" wrote
Keith G wrote:
"Arny Krueger" wrote

Smiley = joke. yes, the idea that the random corruptions of the
audio
signal associated with modern tubed gear and any vinyl playback
equipment would make things categorically sound better is indeed a
joke.


Yet, that they most categorically *do* is one of the Great Mysteries
Of
The Modern Age....

In your mind they do, it's one of the Great Mysteries Of The Stone
Age....

Are you another one *in denial*?

In case you are not aware, you can very easily buy a *brand spanking new*
valve amp, record player and LPs to play on them....

I'd rather avoid the distortion of the valves and the sheer inconvenience
of
the LPs never mind the scratches, pops, rumble, hiss, sloppy frequency
response
etc.



You forgot the *boiled cabbage smell*....

:-)



I do have a Garrard 401 and Ortofon arm btw. It hasn't seen serious use in
around 20 years.


Hardly surprising, given the views expressed above - maybe it's needs the
bearing looking at or greasing?



Seriously, tube 'enhancement' doesn't work for everything by a long
way.

I don't see valves as 'enhancement' myself,

They're used as a 'special effect' mostly in music recording.


You've been paying too much attention to Arny....



but accepting that you do, name
one thing they don't work for - in a strictly audio context, of course...

Any form of highly detailed music. They 'muzz it up'.


??

Get someone to sort your kit out, fit a new needle, clean your records up
and then see if they're muzzy! (Unless they've already been damaged, of
course!) IME, vinyl is easily capable of *shattering clarity*, particularly
on valve kit, compared with the usual *haze* (blurriness, my partner calls
it) you get on digital/SS stuff!

Improving loudspeaker crossovers (SBL's)
 

Keith G wrote:

"Eeyore" wrote

They're [valves] used as a 'special effect' mostly in music recording.

You've been paying too much attention to Arny....

No, I'm 'paying too much attention' - LOL - to the equipment I see in the 'toy
racks' in studios.

How many serious recording studios are you familiar with ? Studios like AIR for
example.

Quite seriously are you not aware that's what they typically use valves for ?
They are intentionally used for their colourations when so desired. Otherwise
they are kept WELL out of the signal chain.

Graham