Playing with inexpensive or salvaged speakers is an interesting side hobby to electronics. Most of us have succumbed to that particular bug early in our careers. I can recall articles in Popular Electronics around 1961 on "Sweet Sixteen" loudspeaker arrays (4x4 arrays of cheap 5" speakers) that were supposed to have the extended bass response of a single large twelve or fifteen inch loudspeaker. I didn't bite on that, but a lot of hobbyists did. From what I read later, it was a total fail at reproducing low frequency bass notes, but I never had the opportunity to actually listen to one of them. When we could afford it, wife and I purchased a pair of used Jensen loudspeakers. Those held up through raising two girls and two boys before the loudspeakers finally died... probably from being over-driven during one (or all) of our kids teen-aged years.
What I did eventually do was build two small unvented enclosures for a pair of small, new, replacement loudspeakers intended for mounting in automobile doors. Mounting the speakers in car doors is apparently effective in isolating the rear pressure wave from the front pressure wave of the speaker, thereby avoiding interference effects. But we got rid of the car before installing the speakers, which I discovered a few years later in their original packing boxes.
Mounting a speaker in a sealed box filled with sound-absorbing material is supposed to also be effective. About as effective as mounting a speaker on an "infinite wall" or on a car door to isolate the front and back sides. What I ended up with was two very heavy, bookshelf-sized, speakers with mediocre sound reproduction quality. Useful, but not high-fidelity by any stretch of the imagination. I still haul them out from time-to-time and drive them with a small Radio Shack stereo amplifier pumping out maybe five watts per channel on a good day. Good enough for listening to YouTube music videos on my desktop PC or laptop or streaming audio clips ripped from CDs.
So, yeah, go ahead and build some cabinets... play around with bass-reflex designs and ported tube designs. Go for measuring the Thiele-Small characteristics and use those to guide your enclosure design. By the time you are thirty and are making some big bux in your chosen career, you will probably gladly pay some of those big bux for an off-the-shelf solution, so you can spend more time actually listening to music while pursuing an electronics hobby on the workbench. Well, that works for me but your mileage (or kilometers) may differ.