Crossover 102 question

[tubbsbright]

For a basic crossover, should the Load (Ohms) be the Ohm load of the driver at the crossover point?

[alias2]

Using the drivers impedance at the c/o point is more accurate than using its
nominal impedance, though you can use the nominal impedance via a zobel.

However "cookbook" values for the c/o components for the former will still
be wrong as they assume a resitive load whilst the load is in fact complex.

"cookbook" values give you electrical functions, what actually matters is
the acoustic functions, and the simpler the crossover the more these
acoustic functions matter (to a degree). In other words even if a
crossover is electrically simple, acoustically it should not be.

e.g. see the simple version here :

http://www.zaphaudio.com/Waveguidetmm.html

First order electrical - ~ 2 order Linkwitz-Riley acoustic.
The tweeter is ~ 2nd order L/R acoustic around 2.5Khz -
but the electrical c/o point is first order at ~ 12KHz ......

[tubbsbright]

Thanks...that helps.

[Curt C]

Thanks...that helps.

This will help more:

http://audio.claub.net/software/jbagby.html

With Jeff's software, there is no longer a reason to use the textbook calculations and 'hope for the best'.

Great stuff!!!! :T

C

[tubbsbright]

yuppers..i've been wading my way thru the FRD stuff the past few days (at work ops: ).

It's pretty deep, and I'm just now gathering an understanding of all the different XO pieces look like in diagram form: from l-pads to notch filters and contour filters.

I'm also trying to get the measurement part down too with MLS and Speakerworks.


blech. small brain hurt.

[Maron]

The FRD page is really helpful . I have been going through it also , along with the tutorials on there . I am planing on building the Modual MT's ( thanks for an awesome design Jon ) , but I am the type that has to know how everything works . Talk about a steep learning curve . :roll:

[ThomasW]

I am planing on building the Modual MT's ( thanks for an awesome design Jon ) , but I am the type that has to know how everything works . Talk about a steep learning curve . :roll:

That's a graduate school level crossover design, so have fun...

[Maron]

I knew all that schooling was going to come in handy some day . :yesnod: