It works well with the SEWE300B.

What I wrote in response to your previous query:

If you look in the SEWE300B forum and the ZROCK3 forum you'll see some users and their comments, myself among them.

My room sort of swallows lower frequencies and I am unable to use room treatments (well, "not allowed to" is most accurate). The ZROCK3 works wonderfully for securing the tonal balance I seek, and better than its predecessor component due to its adjustable gain.