12db/oct alignments

[servicetech]

I've seen people using 3 different types of alignments for 12db/oct crossovers:
1: Linkwitz/Riley
2: Butterworth
3: Bessel
I've noticed all set up resonance at the crossover frequency, so what it the difference among the 3? Is one any better than the other?

What is the theory behind how a 12db/oct crossover works? How does the speakers impedance affect the peak voltages at resonance? I know you can't calculate simple Xc and Xl values like in a 6db circuit. Or do you guys even think about this stuff anymore since we have computers to do the work for us these days?

Speaking of computers doing the work is there a good easy to use program that will model output response based on component values?

[Dennis H]

LR gives a flat sum which is ideal. In practice, you usually have to modify it a bit because the acoustic center of the woofer is behind the tweeter.

Passive Crossover Designer is about as easy as it gets and it's free. Requires Excel with VBA and Analysis Toolpack installed (they aren't by default).

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

[cjd]

PCD requires Windows also...

And good measurement data. And... yeah. lotsa stuff.

But it's great for messing around to start to understand stuff. Or, for producing good results if you know what you're doing.

C

[Johnloudb]

This crossover calculator is free. It does
1: Linkwitz/Riley
2: Butterworth
3: Bessel

http://www.apicsllc.com/apics/Misc/filter2.html

But, it's just a rough start, probably won't give you what you need. It's great help for calculating tweeter L-Pads though.

[ThomasW]

I've seen people using 3 different types of alignments for 12db/oct crossovers:
1: Linkwitz/Riley
2: Butterworth
3: Bessel
I've noticed all set up resonance at the crossover frequency, so what it the difference among the 3? Is one any better than the other?

What is the theory behind how a 12db/oct crossover works? How does the speakers impedance affect the peak voltages at resonance? I know you can't calculate simple Xc and Xl values like in a 6db circuit. Or do you guys even think about this stuff anymore since we have computers to do the work for us these days?

Speaking of computers doing the work is there a good easy to use program that will model output response based on component values?

There's a reason we have the FAQ and reference threads area....

http://www.htguide.com/forum/showthread.php4?t=26544

The freeware AADE Filter Design software help section is a tutorial regarding various kinds of filters.

http://www.aade.com/filter32/download.htm

[servicetech]

That AADE software was EXACTLY what I was looking for, THANKS !!!