Hello!
After a lot of work, learned a ton, designing and tinkering, I'm finally happy to present the LittleJet speakers!

(Italian language, but you can skip to 5:39)

(how everything fit inside)

(the final back design)

*** Sine sweep full spectrum, recorded with Spectroid APP on a Honor8 smartphone and built in microphone at 50cm far  (see the red line; not smoothed) ***