Friedrichsen rhymes with:
fredricksen, fredrickson, fredrikson, hendricksen, hendrickson, hendriksen, hendrixson, derickson, derrickson, dirickson, erichsen, ericksen, erickson, ericson, ericsson, eriksen, erikson, eriksson, errickson, fredricksen, fredrickson, fredrikson, hendricksen, hendrickson, hendriksen, hendrixson, henrichsen, henricksen, henrickson, henriksen, henrikson, hinrichsen
Friedrichsen sounds like:
fredericksen, frederickson, frederiksen, fredricksen, fredrickson, fredriksen, fredrikson