www.diyaudio.com/community/threads/the-making-of-the-singing-loudspeakers.408415/
Tuning Linear Phase crossover https://youtu.be/-gVcAEHPNGM
Tuning Linear Phase crossover using muting https://youtu.be/GWfhdo6DCaY
Tuning Minimum (ordinary) Phase crossover using muting https://youtu.be/MTLtLSnUqh4
http://forums.prosoundweb.com/index.php?topic=148306.msg1368687#msg1368687
http://forums.prosoundweb.com/index.php?topic=148306.0
http://forums.prosoundweb.com/index.php?topic=148306.msg1362639#msg1362639
http://forums.prosoundweb.com/index.php?topic=148587.msg1364464#msg1364464
http://forum.show-master.ru/topic17705.html