Active subwoofer

[marne]

Hi to all. I am new and this is my first post.
Sorry for my English, but I'll try to do my best.
My intention is to build an active subwoofer crossover,for frequency of 20-180 Hz about -24db octave and let's say "full optionals". The web is full of this classic schematic, one for all Elliott Sound Products - The Audio Pages (Main Index) , but my intention is to build a switched capacitor filter, that according the few literature I have read , seems easy to build, and can be adapted to own needs.
Old Ic like LMF40 or LMF100 or similar should be usefull, but excluding the manufacturers' data sheets, too much cathedratic for me, on the web /Google , I have no help.
So I am asking if someone of you has experience in this matter and can suggest me some more informations to realize my filter.
Thank you for your help.

[chris661]

Hi.

Your English is almost perfect, don't worry.

I found that Mr Linkwitz has many helpful circuits - I used an active low pass filter for my subwoofer, designed by him.
Active Filters

Chris

[marne]

Originally Posted by chris661

Hi.

Your English is almost perfect, don't worry.

I found that Mr Linkwitz has many helpful circuits - I used an active low pass filter for my subwoofer, designed by him.
Active Filters

Chris

Hi Chris.
Thanks for all , but me too used in the passed Mr. Linkwitz' circuits, that are perfect and "classical" filters using linear IC ,but not circuits using switch capacitors IC I would like to experiment for a new active filters .
Mario

[CharlieLaub]

Why not take a look at the IC LTC1062 from Linear? This is a 5th order low-pass switched capacitor filter in a DIP-8 package. You need only a few components to make the filter work. You can set it up so that you can change the frequency. See the datasheet for details.

Most switched capacitor filters have poor noise, but this one is not bad.

-Charlie

[marne]

Thank you Charlie. Ok, this is interesting and started to read.
But I wonder why is difficult to find circuits using this ICs for filters considering few components,generally with standard values are needed to work.
Mario