[Peter Larsen[_3_]]

Serge Auckland wrote:

I ask also because a project I have in mind for the future is to
change the crossover in the Tannoy 15" Dual Concentric for an
electronic one.

Hmmm ... did that with a pair of 12" once upon a time.

Looking at the circuit diagram of Tannoy's crossover
looks like something that could be replicated with an electronic
device. Am I missing something?

That HF horn is quite close to being an image of Matterhorn, ie. with a peak
at 4 kHz and a first order slope on either side. Try to find a pair of Coral
H100's for use above some 8 kHz and be very happy, that was what I ended up
with doing in 1978. And with a fairly simple passive cross-over, in theory I
still have the diagram and may be able to scan it and put it on my site. A
Technics parametric (the 17" one, sold it and still miss it, very practical)
was a required addition to the system.

What made me revert to passive was the sn-issue, the Luxman MQ80 valve amp I
had purchased to drive the horns was too darn noisy. The Sansui B55 is a
great amp for driving compression drivers, but you need to physically remove
the spectrum analyzer and replacing the coupling cap in the input with a
suitable magnitude polypropylene is advisable.

Be careful with the ex works cross-over boxes, contents are under pressure
due to all the fine detail that has been trapped in them.

Best regards

S.

Kind regards

Peter Larsen

[[email protected]]

On Jan 30, 11:01*am, wrote:
On Jan 30, 8:35*am, "Serge Auckland"
wrote:
wrote in message
THE CROSSOVER POINTS AREN'T THE ISSUE.
The design of the crossover and the speaker
TOGETHER as a system IS the issue. And you
propose to basically ignore this piece of physics.

Dick,

I've seen a number of so-called "audiophile" loudspeakers that have very
simple crossovers, some as simple as a single capacitor, but many which
consist of simple LC sections, with perhaps a single resistor to reduce
tweeter levels. Many such manufacturers make a virtue of their simple
crossover design. Now I know this is all marketing, they make a virtue of
their limitations, but is there any reason that someone with one of these
loudspeakers couldn't use a DSP-based electronic crossover?

He's assuming that the crossover in question has
additional components beyond one of the common
crossover designs. *Such as additional filters to
compensate for peaks or fall off somewhere. *

I am making NO such assumption, and I would kindly
ask that you not assume that everyone works from the
same base of information that you do.

Take for example, the issue of a driver that has a rising
response. Taking a conventional 2-pol filter and staggering
the poles to result in an overdamped response in the
network is one way of dealing with that.

A point I say is just theoretical until we see the
schematic of the crossover in question. *

And without the entrie system information in
hand, a schematic is not going to tell anyone,
especially you, what's going on, because you have
already formed an opinion, unencumbered by fact,
as to what's going on.

An active crossover is an acceptable substitution for a
basic no frills passive crossover. *

That would be another one of those uninformed
opinions.

True, there is a school of thought that additional
complexity in the crossover just introduces as
many problems as it creates. *

That's the same "generally accepted" school of thought
you graduated from?

As you know
the speaker is not a straight load, it has inductive properties as
well. *

Yes, those of us that actually do work in this realm are
well aware of the properties AND well aware of how to
effectively deal with them.

Some would point out capacitive too. *

And so far, all the people you are referring to would
be wrong.

A woofer exhibits alternatively resistive, inductive,
resistive, capacitive, resistive and inductive components
to its impedance as we move up in frequency. But at
NO place is the impedance every anything other than
predominantly are largely resistive.

*Imho all that's what's behind the simple is better
school.

And that's another opinion. Physics has a way of ignoring
opinion, especially the uninformed variety.

*Some of the same proponents of biamping also
recommend simple no frills 6 db or 12 db crossovers from
the mid/tweeter section. *

So what?

There are a number of camps and they all
have their pluses and minuses. *

And some are just plain wrong.

[[email protected]]

On Jan 30, 11:55*am, wrote:
On Jan 30, 11:01*am, wrote:





On Jan 30, 8:35*am, "Serge Auckland"
wrote:
wrote in message
THE CROSSOVER POINTS AREN'T THE ISSUE.
The design of the crossover and the speaker
TOGETHER as a system IS the issue. And you
propose to basically ignore this piece of physics.

Dick,

I've seen a number of so-called "audiophile" loudspeakers that have very
simple crossovers, some as simple as a single capacitor, but many which
consist of simple LC sections, with perhaps a single resistor to reduce
tweeter levels. Many such manufacturers make a virtue of their simple
crossover design. Now I know this is all marketing, they make a virtue of
their limitations, but is there any reason that someone with one of these
loudspeakers couldn't use a DSP-based electronic crossover?

He's assuming that the crossover in question has
additional components beyond one of the common
crossover designs. *Such as additional filters to
compensate for peaks or fall off somewhere. *

I am making NO such assumption, and I would kindly
ask that you not assume that everyone works from the
same base of information that you do.

Take for example, the issue of a driver that has a rising
response. Taking a conventional 2-pol filter and staggering
the poles to result in an overdamped response in the
network is one way of dealing with that.

A point I say is just theoretical until we see the
schematic of the crossover in question. *

And without the entrie system information in
hand, a schematic is not going to tell anyone,
especially you, what's going on, because you have
already formed an opinion, unencumbered by fact,
as to what's going on.

An active crossover is an acceptable substitution for a
basic no frills passive crossover. *

That would be another one of those uninformed
opinions.

True, there is a school of thought that additional
complexity in the crossover just introduces as
many problems as it creates. *

That's the same "generally accepted" school of thought
you graduated from?

As you know
the speaker is not a straight load, it has inductive properties as
well. *

Yes, those of us that actually do work in this realm are
well aware of the properties AND well aware of how to
effectively deal with them.

Some would point out capacitive too. *

And so far, all the people you are referring to would
be wrong.

A woofer exhibits alternatively resistive, inductive,
resistive, capacitive, resistive and inductive components
to its impedance as we move up in frequency. But at
NO place is the impedance every anything other than
predominantly are largely resistive.

*Imho all that's what's behind the simple is better
school.

And that's another opinion. Physics has a way of ignoring
opinion, especially the uninformed variety.

*Some of the same proponents of biamping also
recommend simple no frills 6 db or 12 db crossovers from
the mid/tweeter section. *

So what?

There are a number of camps and they all
have their pluses and minuses. *

And some are just plain wrong.- Hide quoted text -

- Show quoted text -

You have some valid points. But if you would tone down the rant level
some you would probably get them across better. Since you take the
time to post I have to think that is your goal.

Some would point out capacitive too.

And so far, all the people you are referring to would
be wrong.

A woofer exhibits alternatively resistive, inductive,
resistive, capacitive, resistive and inductive components
to its impedance as we move up in frequency. But at
NO place is the impedance every anything other than
predominantly are largely resistive.

Here you claim something to be wrong and yet in the next paragraph
make the same statement. No where did I claim that any of these other
characteristics exceed the resistive load. I have to guess that is
the point of your second sentence though it is difficult to tell from
the poor wording. Are you saying that the only characteristic of the
speaker that matters is the resistive load?

[jakdedert]

vMike wrote:
wrote in message
...
On Jan 29, 1:40 pm, jakdedert wrote:
wrote:

snip

If I owned those speakers I would very likely not consider trying to
biamp them. Partly for some of the reasons you point out. Does that
constitute agreeing with you? :-)
?? Does someone have a link to the OP's speakers. AARC, he id'd them by
a model number (902?) with no brand. Apparently it was something I
'should' know; or he actually listed the brand and I missed it.

This thread is too long to search it out.

jak

I believe he has the B&H 802D's

http://www.avrev.com/home-theater-lo...udpeakers.html

Yes they are B&W 802D's
mike


Okay, now I'm stumped. He's got $12,000 speakers and wanted to hack
into them and DIY a crossover. Some people....

jak

[[email protected]]

On Jan 30, 12:46*pm, jakdedert wrote:
vMike wrote:
wrote in message
...
On Jan 29, 1:40 pm, jakdedert wrote:
wrote:

snip

If I owned those speakers I would very likely not consider trying to
biamp them. Partly for some of the reasons you point out. Does that
constitute agreeing with you? :-)
?? Does someone have a link to the OP's speakers. AARC, he id'd them by
a model number (902?) with no brand. Apparently it was something I
'should' know; or he actually listed the brand and I missed it.

This thread is too long to search it out.

jak

I believe he has the B&H 802D's

http://www.avrev.com/home-theater-lo...nding-loudspea...

Yes they are B&W 802D's
mike

Okay, now I'm stumped. *He's got $12,000 speakers and wanted to hack
into them and DIY a crossover. *Some people....

jak- Hide quoted text -

- Show quoted text -

Agreed, but I think he has already on board with the leave them alone
idea.

[vMike]

"jakdedert" wrote in message
...
vMike wrote:
wrote in message
...
On Jan 29, 1:40 pm, jakdedert wrote:
wrote:

snip

If I owned those speakers I would very likely not consider trying to
biamp them. Partly for some of the reasons you point out. Does that
constitute agreeing with you? :-)
?? Does someone have a link to the OP's speakers. AARC, he id'd them by
a model number (902?) with no brand. Apparently it was something I
'should' know; or he actually listed the brand and I missed it.

This thread is too long to search it out.

jak

I believe he has the B&H 802D's

http://www.avrev.com/home-theater-lo...udpeakers.html

Yes they are B&W 802D's
mike


Okay, now I'm stumped. He's got $12,000 speakers and wanted to hack into
them and DIY a crossover. Some people....

jak

I never intended to hack anything apart. No way
Mike

[vMike]

"vMike" wrote in message
...

"jakdedert" wrote in message
...
vMike wrote:
wrote in message
...
On Jan 29, 1:40 pm, jakdedert wrote:
wrote:

snip

If I owned those speakers I would very likely not consider trying to
biamp them. Partly for some of the reasons you point out. Does that
constitute agreeing with you? :-)
?? Does someone have a link to the OP's speakers. AARC, he id'd them by
a model number (902?) with no brand. Apparently it was something I
'should' know; or he actually listed the brand and I missed it.

This thread is too long to search it out.

jak

I believe he has the B&H 802D's

http://www.avrev.com/home-theater-lo...udpeakers.html

Yes they are B&W 802D's
mike


Okay, now I'm stumped. He's got $12,000 speakers and wanted to hack into
them and DIY a crossover. Some people....

jak

I never intended to hack anything apart. No way
Mike


I simply was considering plugging one amp feed into the upper terminals and
one into the bottom, and use the amps where I could to adjust the crossover
to the speakers. That was it. I didn't realize I would start such a
debate, but it is nice to read some of the opinions.

Mike

[vMike]

wrote in message
...
On Jan 30, 12:46 pm, jakdedert wrote:
vMike wrote:
wrote in message
...
On Jan 29, 1:40 pm, jakdedert wrote:
wrote:

snip

If I owned those speakers I would very likely not consider trying to
biamp them. Partly for some of the reasons you point out. Does that
constitute agreeing with you? :-)
?? Does someone have a link to the OP's speakers. AARC, he id'd them by
a model number (902?) with no brand. Apparently it was something I
'should' know; or he actually listed the brand and I missed it.

This thread is too long to search it out.

jak

I believe he has the B&H 802D's

http://www.avrev.com/home-theater-lo...nding-loudspea...


Plus the place I bought the speakers from was trying to sell me 4 Classe
amps.

mike

[[email protected]]

On Jan 30, 1:11*pm, "vMike" wrote:
wrote in message

...
On Jan 30, 12:46 pm, jakdedert wrote:





vMike wrote:
wrote in message
....
On Jan 29, 1:40 pm, jakdedert wrote:
wrote:

snip

If I owned those speakers I would very likely not consider trying to
biamp them. Partly for some of the reasons you point out. Does that
constitute agreeing with you? :-)
?? Does someone have a link to the OP's speakers. AARC, he id'd them by
a model number (902?) with no brand. Apparently it was something I
'should' know; or he actually listed the brand and I missed it.

This thread is too long to search it out.

jak

I believe he has the B&H 802D's

http://www.avrev.com/home-theater-lo...nding-loudspea....

Plus the place I bought the speakers from was trying to sell me 4 Classe
amps.

mike- Hide quoted text -

- Show quoted text -

Now you're going to sart a whole nother debate, yukyuk :-)

[Peter Larsen[_3_]]

vMike wrote:

Plus the place I bought the speakers from was trying to sell me 4
Classe amps.

The merit of the type of biamping you were considering is that it sells
amplifiers.

mike

Kind regards

Peter Larsen

[GregS[_3_]]

In article , "vMike" wrote:

wrote in message
...
On Jan 30, 12:46 pm, jakdedert wrote:
vMike wrote:
wrote in message
...
On Jan 29, 1:40 pm, jakdedert wrote:
wrote:

snip

If I owned those speakers I would very likely not consider trying to
biamp them. Partly for some of the reasons you point out. Does that
constitute agreeing with you? :-)
?? Does someone have a link to the OP's speakers. AARC, he id'd them by
a model number (902?) with no brand. Apparently it was something I
'should' know; or he actually listed the brand and I missed it.

This thread is too long to search it out.

jak

I believe he has the B&H 802D's

http://www.avrev.com/home-theater-lo...nding-loudspea...


Plus the place I bought the speakers from was trying to sell me 4 Classe
amps.

mike

You probably saved some good money !!

greg

[[email protected]]

On Jan 30, 12:45*pm, wrote:
On Jan 30, 11:55*am, wrote:

You have some valid points. *But if you would
tone down the rant level some you would probably
get them across better. *

The "rant level" in your words, is a direct and immediate
consequence of your misrepresentations and continued
assumptions about what I and others say, mean or intend.
Stick with what you know, I'll stick with what I know,
and you'll find the conversation less out of your control.

In otherwords, please don't be so presumptuous as to
tell me or anyone else what we do or do not know.
your statements such as "He's assuming that the
crossover in question has additional components..."
or " That they used "theory" when designing their
port suggests that they didn't really test anything,"
and the rest are uninformed, insulting rants of their
own.

You're revealed quite clearly you are not well versed
other than popular culture, myth and assumptions
about the physical and practical principles and concepts
of loudspeaker theory, design and implementation, yet
you choose to hold forth as an expert, making uniformed
and sometimes absurd pronouncements. Your comments
about what you consider appropriate or inappropriate
about the components that should be used is especially
revealing of your ignorance.

And I use "ignorance" not in the pejorative but the
factual sense, if you understand what that means.
I am ignorant of central Asian religions, and thus
have the good sense not to hold forth in those
forums. I do not find the fact that I am ignorant
in those topics to be anything other than a recognition
of fact.

It's only if I insist nd behave otherwise does my
ignorance on the topic turn me into an ignoramus.

Some would point out capacitive too.

And so far, all the people you are referring to would
be wrong.

A woofer exhibits alternatively resistive, inductive,
resistive, capacitive, resistive and inductive components
to its impedance as we move up in frequency. But at
NO place is the impedance every anything other than
predominantly are largely resistive.

Here you claim something to be wrong and yet
in the next paragraph make the same statement. *

No, I do not.

No where did I claim that any of these other
characteristics exceed the resistive load. *

Nor did I accuse you of that.

I have to guess that is the point of your second
sentence though it is difficult to tell from the
poor wording. *

I was objecting to, clarifying and detailing what
the impedance of a specific type of driver actually IS,
rather than your statements about simplistic and
incorrect models. The quotations you made are wrong,
as a point of physical fact, simpe as that. Deal with it
and move on.

Are you saying that the only characteristic of the
speaker that matters is the resistive load?

No, I did not say that. READ what I said:

"A woofer exhibits alternatively resistive,
inductive, resistive, capacitive, resistive
and inductive components to its impedance
as we move up in frequency. But at NO
place is the impedance every anything
other than predominantly are largely
resistive."

Where did I say that it's only one thing or another
that matters? Please point that out.

Would it have helped to say that with only very
rare exceptions does a loudspeaker exhibit an
impedance where the absolute value of the phase
angle exceeds 45 degrees? Any system that has
an impedance phase angle that is asymtotically
limited to +-45 degrees is by definition largely
resistive. That's a statement of physical fact.

Do you assert otherwise?

Do you know what this means?

Do you think every reader might know what
this means?

[Mr.T]

"GregS" wrote in message
...
I think you have to consider the crossover-driver interaction. If you
duplicated passive
with active, the driver does not see the same thing. It sees the amplifier
output.
You have to duplicated the whole action of the passive crossover in the
active crossover.

Not so. First you have to assume (possibly incorrectly) that there is a
negative affect from the passive Xover-speaker interaction to bother
changing it in the first place. *IF* that is in fact so, then replicating it
in an active crossover is the last thing you want to do!

However there are plenty of speakers with poorly designed Xovers that may
benefit from a half decently implemented active replacement.
I also agree with Dick that almost any B&W is unlikely to be among them.

Many sub-woofer passive Xovers are good targets though, but then most good
ones aren't passive in the first place.

MrT.

[[email protected]]

On Jan 30, 4:06*pm, wrote:
On Jan 30, 12:45*pm, wrote:

On Jan 30, 11:55*am, wrote:

You have some valid points. *But if you would
tone down the rant level some you would probably
get them across better. *

The "rant level" in your words, is a direct and immediate
consequence of your misrepresentations and continued
assumptions about what I and others say, mean or intend.
Stick with what you know, I'll stick with what I know,
and you'll find the conversation less out of your control.

In otherwords, please don't be so presumptuous as to
tell me or anyone else what we do or do not know.
your statements such as "He's assuming that the
crossover in question has additional components..."
or " That they used "theory" when designing their
port suggests that they didn't really test anything,"
and the rest are uninformed, insulting rants of their
own.

You're revealed quite clearly you are not well versed
other than popular culture, myth and assumptions
about the physical and practical principles and concepts
of loudspeaker theory, design and implementation, yet
you choose to hold forth as an expert, making uniformed
and sometimes absurd pronouncements. Your comments
about what you consider appropriate or inappropriate
about the components that should be used is especially
revealing of your ignorance.

And I use "ignorance" not in the pejorative but the
factual sense, if you understand what that means.
I am ignorant of central Asian religions, and thus
have the good sense not to hold forth in those
forums. I do not find the fact that I am ignorant
in those topics to be anything other than a recognition
of fact.

It's only if I insist nd behave otherwise does my
ignorance on the topic turn me into an ignoramus.

Some would point out capacitive too.

And so far, all the people you are referring to would
be wrong.

A woofer exhibits alternatively resistive, inductive,
resistive, capacitive, resistive and inductive components
to its impedance as we move up in frequency. But at
NO place is the impedance every anything other than
predominantly are largely resistive.

Here you claim something to be wrong and yet
in the next paragraph make the same statement. *

No, I do not.

No where did I claim that any of these other
characteristics exceed the resistive load. *

Nor did I accuse you of that.

I *have to guess that is the point of your second
sentence though it is difficult to tell from the
poor wording. *

I was objecting to, clarifying and detailing what
the impedance of a specific type of driver actually IS,
rather than your statements about simplistic and
incorrect models. The quotations you made are wrong,
as a point of physical fact, simpe as that. Deal with it
and move on.

Are you saying that the only characteristic of the
speaker that matters is the resistive load?

No, I did not say that. READ what I said:

* *"A woofer exhibits alternatively resistive,
* *inductive, resistive, capacitive, resistive
* *and inductive components to its impedance
* *as we move up in frequency. But at NO
* *place is the impedance every anything
* *other than predominantly are largely
* *resistive."

Where did I say that it's only one thing or another
that matters? Please point that out.

Would it have helped to say that with only very
rare exceptions does a loudspeaker exhibit an
impedance where the absolute value of the phase
angle exceeds 45 degrees? Any system that has
an impedance phase angle that is asymtotically
limited to +-45 degrees is by definition largely
resistive. That's a statement of physical fact.

Do you assert otherwise?

Do you know what this means?

Do you think every reader might know what
this means?

I said:
Some would point out capacitive too.

You said:
And so far, all the people you are referring to would
be wrong.

How else could this sentence be interpreted as any thing but
disagreeing with my statement?

Then you went on to say:
A woofer exhibits alternatively resistive, inductive,
resistive, capacitive, resistive and inductive components

How could this be interpreted as saying anything other than a speaker
has capacitive characteristics?

Yes, my statements are simplistic. The point I was making was that
you can not design a crossover in a vacuum. The speakers and the
cabinet have an effect on the process as well. A point which I think
was what you also raised in comparison of an active crossover verses
the passive crossover? I did not think the addition complexities were
needed to make the point. Was there a different conclusion to be
drawn from your comparision of generic active verses a specific
passive design?

All communications is based on assumptions. People make statements.
The readers come to conclusions about what they think is being
stated. Those conclusions are assumptions. If wrong then the fault
is not always the reader.

Admittedly on the b&h speakers I am drawing conclusions without a
complete set of facts. Unfortunately in the real world we often have
to do that. I agree they are just opinions. But there is a noticable
different between the speed of sound though air and the speed of golf
balls.

Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers? Or that electrolitic capacitors
are less likely to be high precision and have issues with the
capacitance changing due to aging?

[Peter Larsen[_3_]]

wrote:

Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers?

You just do not have a clue.

Kind regards

Peter Larsen

[Mr.T]

"Peter Larsen" wrote in message
...
wrote:

Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers?

You just do not have a clue.

Actually he's partly right. The non linearities may be small in most cases,
and probably a lot less than the drivers themselves, and probably
inconsequential to the system performance, BUT as an absolute statement, and
assuming (yes big assumption) all other inductor parameters are the same,
(obviously ignoring cost, size etc) then the ferrite cored inductor *may* be
"inferior" to the air cored one.

However given all the caveats necessary for that, I'd say your statement is
probably the more accurate :-)

MrT.

[[email protected]]

On Feb 3, 9:18*pm, "Mr.T" MrT@home wrote:
"Peter Larsen" wrote in message

...

wrote:

Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers?

You just do not have a clue.

Actually he's partly right. The non linearities may be small in most cases,
and probably a lot less than the drivers themselves, and probably
inconsequential to the system performance, BUT as an absolute statement, and
assuming (yes big assumption) all other inductor parameters are the same,
(obviously ignoring cost, size etc) then the ferrite cored inductor *may* be
"inferior" to the air cored one.

However given all the caveats necessary for that, I'd say your statement is
probably the more accurate :-)

MrT.

I notice you both avoided the electrolitic question all together.

As to the air core verses ferite core cost is not a factor in this
case. The speakers in question have a suggested retail of $12k a pair.

[[email protected]]

On Feb 3, 6:27*pm, "Peter Larsen" wrote:
wrote:
Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers?

You just do not have a clue.

* Kind regards

* Peter Larsen

That's funny cause I'm starting to think you are an egotistical know-
it-all that has driven away all his real friends so he now spends his
time trying to prove to everyone on the internet how smart he is.
How's that for a clue?

[Mr.T]

wrote in message
...
I notice you both avoided the electrolitic question all together.

Similar arguments apply, especially at lower frequencies where large values
of capacitance may be required. Most manufacturers will avoid electro's if
they can, so I'll bet B&W don't use a 1uF electro for example.

As to the air core verses ferite core cost is not a factor in this
case. The speakers in question have a suggested retail of $12k a pair.

How can cost not be a factor? Even B&W makes more expensive speakers than
that! As do a large number of manufacturers. Some compromises must be made
to hit that price point. You'd prefer cheaper drivers and better inductors
perhaps?

In any case there are other factors to consider like size and weight for
example, if you want high power and low resistance. People these days seem
to dislike speakers the size and weight of refrigerators, even though they
usually have less compromises IMO :-)

MrT.

[David Nebenzahl]

On 2/4/2009 11:20 AM spake thus:

I notice you both avoided the electrolitic question all together.

You know, if you're going to discuss something technical as if you knew
anything about it, you might as well try to spell it right.

It's *electrolytic*.

You're welcome.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[[email protected]]

On Feb 4, 7:30*pm, "Mr.T" MrT@home wrote:
wrote in message

...

I notice you both avoided the electrolitic question all together.

Similar arguments apply, especially at lower frequencies where large values
of capacitance may be required. Most manufacturers will avoid electro's if
they can, so I'll bet B&W don't use a 1uF electro for example.

As to the air core verses ferite core cost is not a factor in this
case. *The speakers in question have a suggested retail of $12k a pair..

How can cost not be a factor? Even B&W makes more expensive speakers than
that! As do a large number of manufacturers. Some compromises must be made
to hit that price point. You'd prefer cheaper drivers and better inductors
perhaps?

In any case there are other factors to consider like size and weight for
example, if you want high power and low resistance. People these days seem
to dislike speakers the size and weight of refrigerators, even though they
usually have less compromises IMO :-)

MrT.

I'm having a hard time seeing a difference in cost at this price range
or weight to explain it. These speakers are suggested retail of $12k
a pair and weigh a whopping176 lbs each. If you wanted to make a case
that other factors are more significant than these component choices I
might go for it. Or maybe they just couldn't come up with some flashy
sounding sales hype for them. My hypo-meter is already going off
anyway. I'm sure these speakers sound great but for me finding out
they used ferrite cores and eletrolitics is a bit like finding out
your ferrari has cast pistons.

I mean 'vapor depositing carbon' on the tweeter? I see no mention of
what the substrate is. Or just how many micrometers of carbon they
deposit. Think there is real science behind the benefits of
depositing carbon on the surface of a tweeter? Or is it just cool to
say "diamond tweeter'.

And 'dimpled much like a golf ball'? Admittedly the ability for a
computer simulate the behavior of the boundary layer is very advanced
these days. I'd still like to see some lab results. Think those
really exist? Think the effect of the boundary layer inside the port
is significant compared to the opening turbulence?

Interestingly these speakers have two sets of terminals and they are
jumpered. It's difficult to tell for certain but it seems that one
set does connect to the low side. The passive crossover spec for the
low is 350hz. Seems to me that even though the passive crossover
remains in the system, placing an active crossover also set at 350hz
up stream of two amps would have no detrimental effect? I do believe
that there is a benefit to having the mid/high swinging at the amp
output center rather than sitting on top of some massive bass note.

[Peter Larsen[_3_]]

Mr.T MrT@home wrote:

"Peter Larsen" wrote in message
...

wrote:

Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers?

You just do not have a clue.

Actually he's partly right. The non linearities may be small in most
cases, and probably a lot less than the drivers themselves, and
probably inconsequential to the system performance, BUT as an
absolute statement, and assuming (yes big assumption) all other
inductor parameters are the same, (obviously ignoring cost, size etc)
then the ferrite cored inductor *may* be "inferior" to the air cored
one.

IF a core was a conductor you - and he - would be in agreement with my
religion on this, but a core is a metal piece inside a coil of conducting
wire. But then there is the cost of the required amount of copper to get
similar resistance in the air cored coil, and it ends up with an active
cross-over being cheaper to implement than a high quality passive.

However given all the caveats necessary for that, I'd say your
statement is probably the more accurate :-)

Mr. Raymond Cooke of KEF preferred cored coils because that allowed him to
dimension them to protect the units. Unofficial information received from
the guys who imported KEF to Denmark way long time ago.

MrT.

Kind regards

Peter Larsen

[Peter Larsen[_3_]]

wrote:

On Feb 3, 6:27 pm, "Peter Larsen" wrote:
wrote:

Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers?

You just do not have a clue.

Kind regards

Peter Larsen

That's funny cause I'm starting to think you are an egotistical know-
it-all that has driven away all his real friends so he now spends his
time trying to prove to everyone on the internet how smart he is.

Some of the time I do come across as arrogant because of occasionally
refusing to dúmb my typing down. I don't have a problem with it. If you DO
have a problem with it, then just skip what I write.

How's that for a clue?

You do NOT have a clue when you describe a coil core, be it air or metal, as
a conductor. The current to the loudspeaker does NOT pass through it.

Kind regards

Peter Larsen

[GregS[_3_]]

In article , wrote:
On Feb 4, 7:30=A0pm, "Mr.T" MrT@home wrote:
wrote in message

...

I notice you both avoided the electrolitic question all together.

Similar arguments apply, especially at lower frequencies where large valu=
es
of capacitance may be required. Most manufacturers will avoid electro's i=
f
they can, so I'll bet B&W don't use a 1uF electro for example.

As to the air core verses ferite core cost is not a factor in this
case. =A0The speakers in question have a suggested retail of $12k a pair=
..

How can cost not be a factor? Even B&W makes more expensive speakers than
that! As do a large number of manufacturers. Some compromises must be mad=
e
to hit that price point. You'd prefer cheaper drivers and better inductor=
s
perhaps?

In any case there are other factors to consider like size and weight for
example, if you want high power and low resistance. People these days see=
m
to dislike speakers the size and weight of refrigerators, even though the=
y
usually have less compromises IMO :-)

MrT.

I'm having a hard time seeing a difference in cost at this price range
or weight to explain it. These speakers are suggested retail of $12k
a pair and weigh a whopping176 lbs each. If you wanted to make a case
that other factors are more significant than these component choices I
might go for it. Or maybe they just couldn't come up with some flashy
sounding sales hype for them. My hypo-meter is already going off
anyway. I'm sure these speakers sound great but for me finding out
they used ferrite cores and eletrolitics is a bit like finding out
your ferrari has cast pistons.

In keeping with space requirments and resistance, an inductor may have
been necessary.

I mean 'vapor depositing carbon' on the tweeter? I see no mention of
what the substrate is. Or just how many micrometers of carbon they
deposit. Think there is real science behind the benefits of
depositing carbon on the surface of a tweeter? Or is it just cool to
say "diamond tweeter'.

Maybe it works.

And 'dimpled much like a golf ball'? Admittedly the ability for a
computer simulate the behavior of the boundary layer is very advanced
these days. I'd still like to see some lab results. Think those
really exist? Think the effect of the boundary layer inside the port
is significant compared to the opening turbulence?

Interestingly these speakers have two sets of terminals and they are
jumpered. It's difficult to tell for certain but it seems that one
set does connect to the low side. The passive crossover spec for the
low is 350hz. Seems to me that even though the passive crossover
remains in the system, placing an active crossover also set at 350hz
up stream of two amps would have no detrimental effect? I do believe
that there is a benefit to having the mid/high swinging at the amp
output center rather than sitting on top of some massive bass note.

No. You don't do it that way. A crossover is only a generic name for a specifically
designed system with a lot of variables. If you add another crossover, you have no idea
what your getting to.

greg

[[email protected]]

On Feb 5, 12:24*pm, (GregS) wrote:
In article , wrote:





On Feb 4, 7:30=A0pm, "Mr.T" MrT@home wrote:
wrote in message

....

I notice you both avoided the electrolitic question all together.

Similar arguments apply, especially at lower frequencies where large valu=
es
of capacitance may be required. Most manufacturers will avoid electro's i=
f
they can, so I'll bet B&W don't use a 1uF electro for example.

As to the air core verses ferite core cost is not a factor in this
case. =A0The speakers in question have a suggested retail of $12k a pair=
..

How can cost not be a factor? Even B&W makes more expensive speakers than
that! As do a large number of manufacturers. Some compromises must be mad=
e
to hit that price point. You'd prefer cheaper drivers and better inductor=
s
perhaps?

In any case there are other factors to consider like size and weight for
example, if you want high power and low resistance. People these days see=
m
to dislike speakers the size and weight of refrigerators, even though the=
y
usually have less compromises IMO :-)

MrT.

I'm having a hard time seeing a difference in cost at this price range
or weight to explain it. *These speakers are suggested retail of $12k
a pair and weigh a whopping176 lbs each. If you wanted to make a case
that other factors are more significant than these component choices I
might go for it. *Or maybe they just couldn't come up with some flashy
sounding sales hype for them. *My hypo-meter is already going off
anyway. *I'm sure these speakers sound great but for me finding out
they used ferrite cores and eletrolitics is a bit like finding out
your ferrari has cast pistons.

In keeping with space requirments and resistance, an inductor may have
been necessary.

I mean 'vapor depositing carbon' on the tweeter? *I see no mention of
what the substrate is. *Or just how many micrometers of carbon they
deposit. *Think there is real science behind the benefits of
depositing carbon on the surface of a tweeter? *Or is it just cool to
say "diamond tweeter'.

Maybe it works.

And 'dimpled much like a golf ball'? *Admittedly the ability for a
computer simulate the behavior of the boundary layer is very advanced
these days. *I'd still like to see some lab results. *Think those
really exist? *Think the effect of the boundary layer inside the port
is significant compared to the opening turbulence?

Interestingly these speakers have two sets of terminals and they are
jumpered. *It's difficult to tell for certain but it seems that one
set does connect to the low side. *The passive crossover spec for the
low is 350hz. *Seems to me that even though the passive crossover
remains in the system, placing an active crossover also set at 350hz
up stream of two amps would have no detrimental effect? *I do believe
that there is a benefit to having the mid/high swinging at the amp
output center rather than sitting on top of some massive bass note.

No. You don't do it that way. A crossover is only a generic name for a specifically
designed system with a lot of variables. If you add another crossover, you have no idea
what your getting to.

greg- Hide quoted text -

- Show quoted text -

Yes, I'll admit that's possible. We have no idea what the slope of
the internal crossover is. And the addition of another slope does
have a effect. If the internal slope is high, say 24bd, would it
really matter if we made it sharper because of an external crossover
as long as we did not introduce any phase shift? The passive
crossover is already designed to be connected directly to an amp.

They have apparently designed the speaker so that the woofers could be
connected to a different amp from the mid/high. I see no advantage to
that configuration unless you have an active crossover upstream. I
did not find anything online about how to use the feature.

[[email protected]]

On Feb 5, 12:23*pm, "Peter Larsen" wrote:
wrote:
On Feb 3, 6:27 pm, "Peter Larsen" wrote:
wrote:
Do you not think that ferite cores are an inferior inductor over air
core for use in passive crossovers?
You just do not have a clue.
Kind regards
Peter Larsen
That's funny cause I'm starting to think you are an egotistical know-
it-all that has driven away all his real friends so he now spends his
time trying to prove to everyone on the internet how smart he is.

Some of the time I do come across as arrogant because of occasionally
refusing to dúmb my typing down. I don't have a problem with it. If you DO
have a problem with it, then just skip what I write.

How's that for a clue?

You do NOT have a clue when you describe a coil core, be it air or metal, as
a conductor. The current to the loudspeaker does NOT pass through it.

* Kind regards

* Peter Larsen

I never suggested that the current to the speaker passes through the
core. You get jump to the conclusion that I suggested the speaker
current passes through the core. Go ahead, find that in one of my
posts.

The concern is that any metal core introduces yet additional
properties to the inductor. And you know that it does. If you want
to take the position that they are negligible in this situation that's
fine.

[Peter Larsen[_3_]]

wrote:

Do you not think that ferite cores are an inferior inductor over

I never suggested that the current to the speaker passes through the
core. You get jump to the conclusion that I suggested the speaker
current passes through the core. Go ahead, find that in one of my
posts.

I misread you as you can see from my followup to T, I'm sorry.

The concern is that any metal core introduces yet additional
properties to the inductor. And you know that it does. If you want
to take the position that they are negligible in this situation that's
fine.

I didn't.

Kind regards

Peter Larsen

[Mr.T]

"Peter Larsen" wrote in message
...
IF a core was a conductor you - and he - would be in agreement with my
religion on this, but a core is a metal piece inside a coil of conducting
wire.

Yes, and metal cores have some hysterisis, as does ferrite.

But then there is the cost of the required amount of copper to get
similar resistance in the air cored coil,

As already mentioned, and size, weight etc.

Mr. Raymond Cooke of KEF preferred cored coils because that allowed him to
dimension them to protect the units.

What does that mean?

MrT.

[Mr.T]

wrote in message
...
Yes, I'll admit that's possible. We have no idea what the slope of
the internal crossover is. And the addition of another slope does
have a effect. If the internal slope is high, say 24bd, would it
really matter if we made it sharper because of an external crossover
as long as we did not introduce any phase shift?

Of course you would, the overlap region will be reduced which may create a
response dip for example.

The passive
crossover is already designed to be connected directly to an amp.

And is already designed (or should be) to give the flattest response with
that combination of drivers.

They have apparently designed the speaker so that the woofers could be
connected to a different amp from the mid/high. I see no advantage to
that configuration unless you have an active crossover upstream.

Actually there is still a benefit even if both amps are full range. You can
use a bigger amp for the bass, and a smaller one that *may* give better
performance at the higher frequencies. It is usually easier to make a
smaller amp with less noise for example.

And then some people also believe in simple Bi-wiring, and it's so easy to
provide for, that many manufacturers do.

MrT.

[Peter Larsen[_3_]]

Mr.T MrT@home wrote:

Mr. Raymond Cooke of KEF preferred cored coils because that allowed
him to dimension them to protect the units.

What does that mean?

Saturation is not always a bad thing. Getting too close to in in normal use
is however, I have heard a dramatic system improvement in the deep bass
range when a cored coil was replaced by an air cored.

MrT.

Kind regards

Peter Larsen

[Mr.T]

"Peter Larsen" wrote in message
...
Mr. Raymond Cooke of KEF preferred cored coils because that allowed
him to dimension them to protect the units.

What does that mean?

Saturation is not always a bad thing.

OK, how does the core saturation of the coil help protect the drive unit?
Possibly in a HF bypass coil I guess. Pity they are easier to make air cored
than in the LF range.

I have heard a dramatic system improvement in the deep bass
range when a cored coil was replaced by an air cored.

So now you are agreeing with James?

MrT.

[[email protected]]

On Feb 6, 12:04*am, "Mr.T" MrT@home wrote:
"Peter Larsen" wrote in message

...

Mr. Raymond Cooke of KEF preferred cored coils because that allowed
him to dimension them to protect the units.

What does that mean?

Saturation is not always a bad thing.

OK, how does the core saturation of *the coil help protect the drive unit?
Possibly in a HF bypass coil I guess. Pity they are easier to make air cored
than in the LF range.

I have heard a dramatic system improvement in the deep bass
range when a cored coil was replaced by an air cored.

So now you are agreeing with James?

MrT.

Let's not get carried away, where's the fun in that.

[[email protected]]

On Feb 5, 8:57*pm, "Mr.T" MrT@home wrote:
wrote in message

...

Yes, I'll admit that's possible. *We have no idea what the slope of
the internal crossover is. *And the addition of another slope does
have a effect. *If the internal slope is high, say 24bd, would it
really matter if we made it sharper because of an external crossover
as long as we did not introduce any phase shift?

Of course you would, the overlap region will be reduced which may create a
response dip for example.

The passive
crossover is already designed to be connected directly to an amp.

And is already designed (or should be) to give the flattest response with
that combination of drivers.

They have apparently designed the speaker so that the woofers could be
connected to a different amp from the mid/high. *I see no advantage to
that configuration unless you have an active crossover upstream.

Actually there is still a benefit even if both amps are full range. You can
use a bigger amp for the bass, and a smaller one that *may* give better
performance at the higher frequencies. It is usually easier to make a
smaller amp with less noise for example.

And then some people also believe in simple Bi-wiring, and it's so easy to
provide for, that many manufacturers do.

MrT.

Nothing personal but I'm afraid I disagree completely about two amps
running full range. Frankly I believe the only gain in bi-amping is
to separate the signal and isolate the larger bass signal from the
rest. And bi-wiring is just total crap. People used to believe the
world was flat, that was crap too.

So perhaps the solution is to send the 250hz and up range to the high
amp and the 450hz and down range to the low amp. Then the slope of
the active crossovers starts 50hz away from the passive ones. No
longer your off the shelf active crossover now though. But since it
would be a fixed crossover points it would be a simple matter to
construct a high impedance one.

[Peter Larsen[_3_]]

Mr.T MrT@home wrote:

"Peter Larsen" wrote in message
...

Mr. Raymond Cooke of KEF preferred cored coils because that allowed
him to dimension them to protect the units.

What does that mean?

Saturation is not always a bad thing.

OK, how does the core saturation of the coil help protect the drive
unit? Possibly in a HF bypass coil I guess. Pity they are easier to
make air cored than in the LF range.

I have heard a dramatic system improvement in the deep bass
range when a cored coil was replaced by an air cored.

So now you are agreeing with James?

My point of view remains that it the cost of making a ""proper"" passive
crossover is so high that it is folly to so do. A bass unit that sounds
better with an air cored coil than with a ferrite cored coil still sounds
best with no coil between it and the amp. Consequently I'd never bother with
replacing the ferrite cored coil and I remain convinced that one should not
so do in case of a computer optimized cross-over because its exact
properties are factored in and one might get a mid range cost for the better
orchestral bass drum.

MrT.

Kind regards

Peter Larsen