Looking for a line-level xover calculator

[Dan_ed]

or equations will do.

My goal is to come up with some passive pllxo circuits for a 4th order Linkwitz-Riley filter. I'd like to experiment with some different values before committing to a more permanent solution.

Any help is appreciated.

Dan

[richie00boy]

4th-order passive is almost impossible due to the impedance issue. Also you can't do Linkwitz-Riley with 4th-order, the Q will be 0.25 which is very droopy and probably quite poor for audio. You can only get Linkwitz-Riley in 2nd-order if you go passive, even that is difficult and would need a buffer and driver.

[theAnonymous1]

There is some good info at the below link, no calculator though.....

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

[Dan_ed]

Originally posted by richie00boy
4th-order passive is almost impossible due to the impedance issue. Also you can't do Linkwitz-Riley with 4th-order, the Q will be 0.25 which is very droopy and probably quite poor for audio. You can only get Linkwitz-Riley in 2nd-order if you go passive, even that is difficult and would need a buffer and driver.

Hhhmmmmm. Maybe someone should tell Marchand. ;-)

[sreten]

Originally posted by richie00boy
Also you can't do Linkwitz-Riley with 4th-order

Hi,

Yes you can.

In fact the 4th order version is by far the original "famous" version,
(It is two cascaded or squared 2nd order Butterworth filters)
the 2nd order version becoming more popular and much abused
later, 2nd order electrical L/R is not L/R acoustic nearly always.

There is a L/R alignment for all even (2nd, 4th, 6th, 8th etc.) orders.

http://www.linkwitzlab.com/filters.htm

/sreten.

See http://www.linkwitzlab.com/proto.htm for PLLXO examples.
without inductors you are limited to low Q second order.

[AndrewT]

Originally posted by richie00boy
4th-order passive is almost impossible due ......

most expensive speakers with selected component values stop at 3rd order due to the difficulty/expense of achieving the accuracy for 4th order.

First order is very tolerant of component values.
Second order requires some accuracy to achieve the desired roll off.
Third order requires much greater component value accuracy.

[Dan_ed]

Unfortunately, the linkwitz lab link only shows the topic for active crossovers. I am looking for passive and line level.

[cuibono]

Just recently I was looking into PLLXO's, and concluded that for a complex and/or higher order, one would have to go active. Input and output impedance, and insertion loss are the big problems here.

[sreten]

Originally posted by Dan_ed
Unfortunately, the linkwitz lab link only shows the topic for active crossovers.
I am looking for passive and line level.

This may be useful : http://focus.ti.com/docs/toolsw/fold...t/tina-ti.html

/sreten.

[impsick]

Here you go

4th order Linkwitz-Riley crossover calculator. Hope it works for you.