Diy Audio

inexpensive speakers are everywhere, amazon, monoprice, many other volume vendors

not sure diy will result in a less money spent nor better sound for measly $$ spent

If you can’t afford Dayton Audio B452-AIR 4-1/2’s, you can’t afford surround. You will NEVER make any better rears for less.

look for a vintage or used shop / online locally and buy used. don't bother trying to work with that driver with out its specs you wont get it to work correctly. and its probably not going to do much in the top end or bottom end. and have you priced wood recently? 

The issue with drivers you just found is you don't have the parameters to build a good box for them. Next, if these are mid-woofers they wont' have enough treble.

If you want to make a single driver surround you might want to look at some of the 4" Peerless drivers.  White one's Super cheap, good treble extension but not wide dispersion.

Mark989, I applaud your desire to build your own speakers.  When I first built my own speakers about fifty years ago I started out with zero budget and near zero knowledge.  My first effort was literally built with drivers and plywood I scavenged from a trash dump.  They were horrible midrange honkers, but the project was so much fun I got hooked.  Then I wised up and began studying the subject of how to design and build speakers.  In those days before PCs or the internet information was hard to find, but a few books such as Badmieff and Davis book, How to Build Speaker Enclosures, got me started.  Now a tremendous amount of knowledge is available as near as a Duck Duck Go search on how to build speakers.  That is how I suggest you get started.