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Old October 25th 04, 09:02 AM posted to uk.rec.audio
Nick Brooks
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Posts: 16
Default Low-pass filter thoughts

Eiron wrote:
Wally wrote:

Eiron wrote:


You really are better off with steep high and low pass filters.
Trying to match the hf response of a sub to the lf response of a
mid-range box is difficult, and putting a lot of power through the
mid-range below its resonant frequency is asking for trouble.




The 'midrange' is a KEF B110, which I believe has a sufficiently low
resonant frequency to serve as a bass driver as well.



I'm listening to one at the moment.
I like them but Stuart P thinks that the sound from a Bextrene cone
collapses at low levels.

Here are some specs for a typical box using the B110:
http://www.mhennessy.f9.co.uk/rogers/ls35a_page4.jpg

If you use an open baffle or reflex box then the cone will flap about
dangerously at moderate power levels (without a high-pass filter)
You should be OK with a closed box and up to a 100w amp
but I would still recommend a 2-way 4th-order Linkwitz-Riley crossover
at 100hz or higher.


Very good active crossovers can be obtained from Marchand Electronics.
Fully assembled variable crossover frequency (XM9) = $700. Single
crossover frequency kit (XM1)= $100

No connection. just a happy customer

N