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Old January 17th 07, 03:59 PM posted to uk.rec.audio
Don Pearce
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Posts: 1,822
Default Crossover questions.....

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

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