The unknown ones have 2 nice features. the reset button is for some overload protection.
and the level control lets you boost or lower mids and or tweeters volume relative to the woofer's volume: to refine/balance the sound in any particular space: boost for a dull soft surfaced space; cut for a live hard surfaced space.
It's time to listen.
I finally bought an in-expensive sound meter. It doesn't need perfect calibration, just show individual frequency band DB levels relative to each other. Wish I bought my own years ago. Used a pro's back then.
I have many CD test discs, I like my Carver one best, it has specific track numbers, 9-38, and each track is 1 minute long, far easier to use, press track, watch meter, pause, adjust, press play... back and forth, each speaker to itself/match the other, and then reduce/refine for the combined stereo output. a wonderful tool, tripod, ear level at listening position, refine placement from corners, toe-in .....