Send the following on WhatsApp
Continue to ChatLinkwitz-Filter https://www.haeussler.name/blogs/hobby/lautsprecher/subwoofer-isophone-pls-320-400-s/attachment/dscn0318/
Linkwitz-Filter https://www.haeussler.name/blogs/hobby/lautsprecher/subwoofer-isophone-pls-320-400-s/attachment/dscn0318/