Simple Aktive Crossover needed

[drumheadz]

Hi Folks i need a simple aktive crossover like Harrissons F-Mod can anyone give me some info hove to do a active/Passive Crossover for the line signal without making it a complex filter i only want to cut everything under 90Hz in the line signal path and not on the speaker lines!,,, Cheerz Dag Zimmermann Stockholm sweden

PS: exuse my english im swedish you know:ds

[phase_accurate]

Hej

If it has to be model-T and the filter doesn't need to be steep then you could simply use a smaller input cap on your power amp. If you don't want to fiddel with the amps internals then you may simply add one in series.

To dimension this properly you'll need the circuit of the input section of the amp. Or at least a reliable input impedance spec.

Regards

Charles

[planet10]

Originally posted by drumheadz
i need a simple aktive crossover like Harrissons F-Mod

An F-mod is simply a passive line level XO (PLLXO) pre-packaged into a big RCA plug.

You can eaily build your own. As Charles says a single cap (+ the existing input resitor on your amp) will give you a passive line level Hi-pass filter (1st order)

Details can be found here.

http://www.t-linespeakers.org/tech/f...ssiveHLxo.html

dave

[AndrewT]

Hi,
a single pole filter will cut at 6db/octave (=20db/decade) below the turn over frequency.
If you set the filter to 90Hz (F-3db), then the signal will be about 9db down at 45Hz and about 15db down at 22.5Hz.
This is not even close to meeting

i only want to cut everything under 90Hz

What do you require?

[phase_accurate]

This is not even close to meeting

There will never ever be any kind of filter that cuts EVERYTHING below 90 Hz - let alone a SIMPLE one.

So I went for the simple solution. If it may be a little more complicated he might just specify how steep a slope he likes or how complicated it may be.

Regards

Charles

[drumheadz]

Tanx a lot folks will read up on the matter and try!...