Two-way Crossover, Audio Project

[audioguru2]

Man! That translation gave me a hard time. The project is here:
http://electronics-lab.com/projects/audio/002/index.html
If wired as shown, then this project produces a notch filter at the crossover frequency. Due to phase shifts of 2nd order filters that are used, sounds at or near the frequency of the 3500Hz crossover from the woofer and tweeter cancel at your ears, if you are on axis and fairly close to the loudspeaker. The sound quality is not good.
If the polarity of one speaker is reversed then the sound quality is much better, except then the frequencies at or near the crossover frequency are a little too loud.
Many audio experts agree with this theory and one expert's explanation is here:
http://www.trueaudio.com/st_mr2.htm
To completely avoid these problems I always build two-way crossovers using 3rd order filters. The additional cost is only 1 capacitor since I use the woofer's voice-coil inductance instead of an additional inductor, and use a standard 3rd order filter calculation for the parts.

 

[hotwaterwizard2]

Can you really tell the difference? Most people can't.
How about 4th order 6th and 8th order crossovers. Check out this cool Crossover Calculator.

http://www.carstereo.com/help2/Articles.cfm?id=13

 

[audioguru2]

Hotwaterwizard,
The notch is very noticeable when you are fairly close to the loudspeaker. But if you are far away in a reverberant room, then reflections partially fill-in the notch, which sounds better.
Thanks for your link about the crossover calculator. The car-stereo guys probably use high-order filters in order to keep their powerful BOOM from blowing-up their tweeters. But high-order filters are impractical because their parts must have non-standard values and very close tolerance.
I notice that your link uses the Linkwitz-Riley (engineers at Hewlett-Packard) response instead of Butterworth in order to avoid the notch when even-ordered.

 

[hotwaterwizard2]

This is the same site. Look at the Knowlege Base lots of good stuf there Lower Left. http://www.carstereo.com/

 

[audioguru2]

Hotwaterwizard,
Thanks for the tip for Carstereo's knowledge base. But their crossover component calculator doesn't work. Maybe I must login?