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ScottW ScottW is offline
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Default Tweeter replacement for Kef 107


"Kalman Rubinson" wrote in message
...
On 1 Mar 2007 19:41:15 -0800, "fid" wrote:

It is obvious that I am a novice here, but please excuse me if I
insist: if the tweeter has the appropriate impedance and sensitivity,
and it has the proper frequency range suitable for the cut-point, why
would I need to modify the crossover network?


Because each of those numbers represents a snapshot of a continuously
varying parameter. Impedance at a single frequency does not
characterise the impedance across the spectrum adequately for
crossover design.


Actually....the term impedance implies a complex
model that will vary response with frequency.

I think you're confusing nominal impedance.

If the complex impedance of the drivers are the same,
then the response of the crossover will not be adversely
affected. Then if the sensitivity of the drivers are the same,
the basic response will be very similar.
Only significant variable left is dispersion patterns and baffle
interaction.

I would agree that most driver specs don't make it easy to
determine the true impedance of the driver.

Similarly, senstivity varies with frequency and the
crossover is designed to account for it.


Freq. sensitivity plots are readily available though.
For example
http://www.madisound.com/pdf/seas/e006.pdf

Picking by those single
numbers is insufficient and barely more useful than picking by color.

I recommend you accept KEF's recommendation.


How much is it?

ScottW