Nice process, I love that you actually made a functional model.
I don’t know of a book, but there’s a great audio forum called DIY audio that’s jammed full of every bit of information about home speakers.
Knowing how to house the speaker to suit its electromagnetic properties (qts is a big one, you’ll probably understand what this actually means in practical terms far more than I do 
) makes an enormous difference to the sound it produces. Ideally, you don’t want the sound waves from the front of the speaker cone to come into contact with the identical wave coming off of the rear of the cone, as they cancel each other out and the sound quality is reduced.
Have a look at different methods of installing speakers into enclosures (sealed, ported, different orders of band pass) and how the amount of air inside the chamber can alter the performance of your speaker. There’s a great free software called WinISD that helps you to design enclosure volumes and ports etc around different speakers if you wanted to have a play.