Crossover questions.....

OK, some techie questions regarding this crossover:

http://www.apah69.dsl.pipex.com/show/crossover1.JPG


1) Anybody care to tell me what order it is (seems pretty basic to me)?

2) Can I slap it between just about any tweeter and similar sized mid/bass
unit with good effect?

3) Will a different box size have any bearing on how it works with the
drivers?

4) Have I marked up the driver connections correctly?


Apologies if these questions are a bit simplistic - I have a bone problem
which prevents me reading reams of techie stuff (and actually *learning*
anything) when a swift thump with a hammer will sort most things out, one
way or another.....

;-)

On Wed, 17 Jan 2007 15:58:23 -0000, "Keith G"
wrote:


OK, some techie questions regarding this crossover:

http://www.apah69.dsl.pipex.com/show/crossover1.JPG


1) Anybody care to tell me what order it is (seems pretty basic to me)?

2) Can I slap it between just about any tweeter and similar sized mid/bass
unit with good effect?

3) Will a different box size have any bearing on how it works with the
drivers?

4) Have I marked up the driver connections correctly?


Apologies if these questions are a bit simplistic - I have a bone problem
which prevents me reading reams of techie stuff (and actually *learning*
anything) when a swift thump with a hammer will sort most things out, one
way or another.....

That's a first order crossover, plus some assorted other stuff.
Basically, the woofer is fed through that big choke. Is there a value
printed on it anywhere? The 4.7ohm and 12MFD at the bottom appear to
be there to keep the impedance of the woofer tidy out of band - they
won't do anything particular to the sound. The tweeter is fed by the
blue cap at the top - can't see the value of that either. The two
parallel resistors will drop the level to the tweeter, so presumably
in the original design the tweeter was more sensitive than the woofer.

You've marked up OK, but without those two vital values, it is
impossible to judge their applicability.

As for boxes - fine, this is a standard crossover design, and it
should work in most cases.

d

--
Pearce Consulting
http://www.pearce.uk.com

Keith G wrote:
OK, some techie questions regarding this crossover:

http://www.apah69.dsl.pipex.com/show/crossover1.JPG


1) Anybody care to tell me what order it is (seems pretty basic to me)?

Looks like first order.

2) Can I slap it between just about any tweeter and similar sized mid/bass
unit with good effect?
Yes to the first part of this question, and possibly to the second part.
It looks like this crossover has a 3.3 ohm resistor in series with the
tweeter, presumably to balance the level with the woofer. I would say
this is done with two specific drive units in mind.


3) Will a different box size have any bearing on how it works with the
drivers?

Should make much difference as box size effects the bass end, and the
crossover works in the middle.

4) Have I marked up the driver connections correctly?

Yes, it will work this way, but to me it looks upside-down with the +
terminal being the common terminal. By convention, it is the negative
that's common, but it *is* only by convention.

How do we know electrons are negatively charged. That's only relative to
protons..........


Apologies if these questions are a bit simplistic - I have a bone problem
which prevents me reading reams of techie stuff (and actually *learning*
anything) when a swift thump with a hammer will sort most things out, one
way or another.....

;-)

Particularly effective for setting cartridge tracking.

S.

"Don Pearce" wrote in message
...
On Wed, 17 Jan 2007 15:58:23 -0000, "Keith G"
wrote:


OK, some techie questions regarding this crossover:

http://www.apah69.dsl.pipex.com/show/crossover1.JPG


1) Anybody care to tell me what order it is (seems pretty basic to me)?

2) Can I slap it between just about any tweeter and similar sized mid/bass
unit with good effect?

3) Will a different box size have any bearing on how it works with the
drivers?

4) Have I marked up the driver connections correctly?


Apologies if these questions are a bit simplistic - I have a bone problem
which prevents me reading reams of techie stuff (and actually *learning*
anything) when a swift thump with a hammer will sort most things out, one
way or another.....

That's a first order crossover, plus some assorted other stuff.


I thought there were too many 'bits' for a 1st Order crossover!! (Shows what
I know....! ;-)


Basically, the woofer is fed through that big choke. Is there a value
printed on it anywhere?


No, the choke has no markings on it at all.


The 4.7ohm and 12MFD at the bottom appear to
be there to keep the impedance of the woofer tidy out of band - they
won't do anything particular to the sound. The tweeter is fed by the
blue cap at the top - can't see the value of that either.


The cap is marked '8 MFD and 50 VNP'....

(VNP...??)


The two
parallel resistors will drop the level to the tweeter, so presumably
in the original design the tweeter was more sensitive than the woofer.



No idea - Vifa units (Ruark Sabres).

The tweeters have been fried and the woofers are doing stirling work in
another box which sounds pretty good!!


You've marked up OK, but without those two vital values, it is
impossible to judge their applicability.

As for boxes - fine, this is a standard crossover design, and it
should work in most cases.


OK Don, - thanks for that - I've marked it 'fit for purpose' and will
proceed blindly, as intended...!! :-)

(VNP...??)

50V non-polar?

cheers, Ian

"Serge Auckland" wrote in message
...
Keith G wrote:
OK, some techie questions regarding this crossover:

http://www.apah69.dsl.pipex.com/show/crossover1.JPG


1) Anybody care to tell me what order it is (seems pretty basic to me)?

Looks like first order.


OK.



2) Can I slap it between just about any tweeter and similar sized
mid/bass unit with good effect?
Yes to the first part of this question, and possibly to the second part.
It looks like this crossover has a 3.3 ohm resistor in series with the
tweeter, presumably to balance the level with the woofer. I would say this
is done with two specific drive units in mind.


Hmm, well it's in for a shock then....




3) Will a different box size have any bearing on how it works with the
drivers?

Should make much difference as box size effects the bass end, and the
crossover works in the middle.


The box won't be too dissimilar in terms of internal volume, I think....




4) Have I marked up the driver connections correctly?

Yes, it will work this way, but to me it looks upside-down with the +
terminal being the common terminal. By convention, it is the negative
that's common, but it *is* only by convention.

How do we know electrons are negatively charged. That's only relative to
protons..........



I only know it because I tend to believe what I'm told 'til I can *prove*
otherwise!! ;-)



Apologies if these questions are a bit simplistic - I have a bone problem
which prevents me reading reams of techie stuff (and actually *learning*
anything) when a swift thump with a hammer will sort most things out, one
way or another.....

;-)

Particularly effective for setting cartridge tracking.


:-)


OK, another one if you and/or Don are up for it.

What about this one:

http://www.apah69.dsl.pipex.com/show/crossover2A.JPG

http://www.apah69.dsl.pipex.com/show/crossover2B.JPG

http://www.apah69.dsl.pipex.com/show/crossover2C.JPG


It don't look too convincing to me (can't really see any values on the bits
better than in the pix - it's still connected) - which would you use for
messing about with (piling spare drivers into a different box on a 'suck it
and see' basis)...??

Atm, my garage/workshop is heaving with various speakers in various stages
of disarray and I need to get it sorted:

http://www.apah69.dsl.pipex.com/show...sgraveyard.JPG

:-)

On Wed, 17 Jan 2007 16:55:33 -0000, "Keith G"
wrote:


"Serge Auckland" wrote in message
...
Keith G wrote:
OK, some techie questions regarding this crossover:

http://www.apah69.dsl.pipex.com/show/crossover1.JPG


1) Anybody care to tell me what order it is (seems pretty basic to me)?

Looks like first order.


OK.



2) Can I slap it between just about any tweeter and similar sized
mid/bass unit with good effect?
Yes to the first part of this question, and possibly to the second part.
It looks like this crossover has a 3.3 ohm resistor in series with the
tweeter, presumably to balance the level with the woofer. I would say this
is done with two specific drive units in mind.


Hmm, well it's in for a shock then....




3) Will a different box size have any bearing on how it works with the
drivers?

Should make much difference as box size effects the bass end, and the
crossover works in the middle.


The box won't be too dissimilar in terms of internal volume, I think....




4) Have I marked up the driver connections correctly?

Yes, it will work this way, but to me it looks upside-down with the +
terminal being the common terminal. By convention, it is the negative
that's common, but it *is* only by convention.

How do we know electrons are negatively charged. That's only relative to
protons..........



I only know it because I tend to believe what I'm told 'til I can *prove*
otherwise!! ;-)



Apologies if these questions are a bit simplistic - I have a bone problem
which prevents me reading reams of techie stuff (and actually *learning*
anything) when a swift thump with a hammer will sort most things out, one
way or another.....

;-)

Particularly effective for setting cartridge tracking.


:-)


OK, another one if you and/or Don are up for it.

What about this one:

http://www.apah69.dsl.pipex.com/show/crossover2A.JPG

http://www.apah69.dsl.pipex.com/show/crossover2B.JPG

http://www.apah69.dsl.pipex.com/show/crossover2C.JPG


It don't look too convincing to me (can't really see any values on the bits
better than in the pix - it's still connected) - which would you use for
messing about with (piling spare drivers into a different box on a 'suck it
and see' basis)...??

Without being able to trace the circuits I can't say for definite, but
that looks like a second order crossover. Are those chokes wound on
ferrite? If they are, this crossover has a power limit set by the
magnetic saturation of the ferrite. Your other one is a better way of
making a crossover choke.

d

--
Pearce Consulting
http://www.pearce.uk.com

"Don Pearce" wrote


Without being able to trace the circuits I can't say for definite, but
that looks like a second order crossover. Are those chokes wound on
ferrite? If they are, this crossover has a power limit set by the
magnetic saturation of the ferrite. Your other one is a better way of
making a crossover choke.


OK, here's a pic of both sides of that crossover:

No, here's a couple of pix showing each side of that crossover:

http://www.apah69.dsl.pipex.com/show/topside.JPG

http://www.apah69.dsl.pipex.com/show/underside.JPG


The game plan is as follows:

Dr Rob very kindly gave me these speakers

http://www.apah69.dsl.pipex.com/show/donor.JPG

which sound fine but are easily beat by most (all, actually) of the other
spreakers I have here, due to a lack of any bass at all. I want to pull the
drivers (T27s and H3310s) out of 'em and use them in these boxes:

http://www.apah69.dsl.pipex.com/show/boxes.JPG

as they are a little larger and have easy, front access - see the original
drivers on a nice, easily removed front baffle he

http://www.apah69.dsl.pipex.com/show/originals.JPG


(Rob - speak now if you would rather have these back instead of me
cannabalising them!)


The idea is to fit the drivers into the boxes (which I will modify hugely
with a second skin and some crossbracing) using the Ruark crossover, leaving
Rob's 'donor' speakers as intact as possible (for a possible
reversal/restoration) and trying a few different drivers (if necessary)
until I can convince myself I have a pair of unique, stunning 'homebrew'
standmounters that blow away any commercial equivalent at many times the
price.....

;-)

(Or find, for only a little work, if I'm ****ing in the breeze!!)

Don Pearce wrote:
On Wed, 17 Jan 2007 16:55:33 -0000, "Keith G"
wrote:

"Serge Auckland" wrote in message
...
Keith G wrote:
OK, some techie questions regarding this crossover:

http://www.apah69.dsl.pipex.com/show/crossover1.JPG


1) Anybody care to tell me what order it is (seems pretty basic to me)?
Looks like first order.

OK.


2) Can I slap it between just about any tweeter and similar sized
mid/bass unit with good effect?
Yes to the first part of this question, and possibly to the second part.
It looks like this crossover has a 3.3 ohm resistor in series with the
tweeter, presumably to balance the level with the woofer. I would say this
is done with two specific drive units in mind.

Hmm, well it's in for a shock then....


3) Will a different box size have any bearing on how it works with the
drivers?
Should make much difference as box size effects the bass end, and the
crossover works in the middle.

The box won't be too dissimilar in terms of internal volume, I think....



4) Have I marked up the driver connections correctly?
Yes, it will work this way, but to me it looks upside-down with the +
terminal being the common terminal. By convention, it is the negative
that's common, but it *is* only by convention.

How do we know electrons are negatively charged. That's only relative to
protons..........


I only know it because I tend to believe what I'm told 'til I can *prove*
otherwise!! ;-)


Apologies if these questions are a bit simplistic - I have a bone problem
which prevents me reading reams of techie stuff (and actually *learning*
anything) when a swift thump with a hammer will sort most things out, one
way or another.....

;-)
Particularly effective for setting cartridge tracking.

:-)


OK, another one if you and/or Don are up for it.

What about this one:

http://www.apah69.dsl.pipex.com/show/crossover2A.JPG

http://www.apah69.dsl.pipex.com/show/crossover2B.JPG

http://www.apah69.dsl.pipex.com/show/crossover2C.JPG


It don't look too convincing to me (can't really see any values on the bits
better than in the pix - it's still connected) - which would you use for
messing about with (piling spare drivers into a different box on a 'suck it
and see' basis)...??

Without being able to trace the circuits I can't say for definite, but
that looks like a second order crossover. Are those chokes wound on
ferrite? If they are, this crossover has a power limit set by the
magnetic saturation of the ferrite. Your other one is a better way of
making a crossover choke.

d

Completely agree.

S.

On Wed, 17 Jan 2007 18:01:28 -0000, "Keith G"
wrote:


"Don Pearce" wrote


Without being able to trace the circuits I can't say for definite, but
that looks like a second order crossover. Are those chokes wound on
ferrite? If they are, this crossover has a power limit set by the
magnetic saturation of the ferrite. Your other one is a better way of
making a crossover choke.


OK, here's a pic of both sides of that crossover:

No, here's a couple of pix showing each side of that crossover:

http://www.apah69.dsl.pipex.com/show/topside.JPG

http://www.apah69.dsl.pipex.com/show/underside.JPG

No, it was too hard to trace from those, but assume they were built on
advice from the driver makers, and they are basically OK.


The game plan is as follows:

Dr Rob very kindly gave me these speakers

http://www.apah69.dsl.pipex.com/show/donor.JPG

which sound fine but are easily beat by most (all, actually) of the other
spreakers I have here, due to a lack of any bass at all. I want to pull the
drivers (T27s and H3310s) out of 'em and use them in these boxes:

http://www.apah69.dsl.pipex.com/show/boxes.JPG


OK, if you are telling me they lack bass, I will certainly believe
you!

as they are a little larger and have easy, front access - see the original
drivers on a nice, easily removed front baffle he

http://www.apah69.dsl.pipex.com/show/originals.JPG


H3310s looks like a Seas pat number, but I can't find any info,
particularly the TS parameters, so I can't offer any help on box
design.


(Rob - speak now if you would rather have these back instead of me
cannabalising them!)


The idea is to fit the drivers into the boxes (which I will modify hugely
with a second skin and some crossbracing) using the Ruark crossover, leaving
Rob's 'donor' speakers as intact as possible (for a possible
reversal/restoration) and trying a few different drivers (if necessary)
until I can convince myself I have a pair of unique, stunning 'homebrew'
standmounters that blow away any commercial equivalent at many times the
price.....

;-)

(Or find, for only a little work, if I'm ****ing in the breeze!!)



I don't think you will get much joy by simply putting them in that
other box; the chances of it being the right size are pretty remote.
And then of course there is the port design to consider. I'll keep on
looking, though.

d

--
Pearce Consulting
http://www.pearce.uk.com