The only option open to you to enjoy good music-- unless you sing or play an instrument or two-- is to have a hi-fi music system. This, as we all know, comprises three basic units-- a source, an amplifier and a pair of 'stereo' speakers. Speakers, as most of us have found out, are as different as individuals; or shall we say as different as their designers! 
Though, if we look at it from a tech angle, not much has changed from the 'electro-dynamic' speaker designed by Kellog and Rice at General Electric Company back in 1925.
Though, if we look at it from a tech angle, not much has changed from the 'electro-dynamic' speaker designed by Kellog and Rice at General Electric Company back in 1925.
( https://www.mixonline.com/technology/1925-chester-rice-edward-kellogg-general-electric-co-modern-dynamic-loudspeaker-377962
https://commons.wikimedia.org/wiki/File:Edward_Kellogg_%26_Chester_Rice_with_cone_speaker_1925.jpg )
And these transducers range in cost from the 'cheap and cheerful' to the stratospherically priced "high end audio" drivers that cost an arm and a leg! But, in the end, they all convert electrical waves into sound...with what fidelity is a moot point, though. And hence their attraction for the hobbyist.
DIY
It is not an accident that the DIY enthusiast has invaded this field also. The individual hobbyist works flexibly within his budget; but s/he has no constraints of time and labour -- difficult things for a commercial operation to manage easily without cutting a corner or two. No wonder then people generally believe that DIY speakers most of the time offer better value than their commercial equivalents.
Being an Xpress DIY site, it is not for us to delve deeply into theoretical stuff. (Relevant Web links will often be attached.) Rather, we tend to concentrate on the practical, in a result-oriented manner. Individuals pursue their hobbies not to participate in a competition, but rather to reap that unique satisfaction that comes with making something with one's own hands. Your speakers are guaranteed to sound sweet, at least to your ears, no matter what--that is the lure of DIY!
To Wood...or No Wood
Though exotic materials have been used in the fabrication of speakers, ranging from carbon fibre to concrete to stainless steel, the commonest of stuff that goes into speaker cabinets is plain wood, or its modern incarnations like plywood, MDF etc. Now this is a factor that strongly deters the average hobbyist. Most of the speakers are housed in one sort of box or another...small, medium, tall, narrow, huge. And it does not take a PhD to imagine how a box will look when made by the average "handyman". Rarely will it achieve "squareness". Joinery is more an art that takes years of instruction and practice to master. Also, wood working needs space and at least some basic machinery--both at a premium for the average enthusiast.
Recently while "locked down" safely at home, my chafing mind and itching hands made some serendipitous discoveries. You don't need all that has been prescribed traditionally for experimenting with speakers! You don't even need wood! Surely I broke the news to my group of 'crony hobbyists' and they too were more than enthused. Yes, all you need is the most basic of tools. A good, sharp and strong box knife ( no power saws or bench saws), a long steel ruler, a Try-square, some emery cloth and PVC pipe cement/glue, and you are armed to take up speaker DIY!
Going Open
One could get away with saying that speaker boxes broadly come in two types-- sealed, and open. The open types are the ones with ducts (called bass reflex), or the types with a column or a horn that tailors the back radiation from the cone. We chose the open types to experiment with as they offer distinct advantages, as against the sealed types. There is no back pressure to be contained, and that means we could get away with simple, less rigid and lighter box structures, and we could also "take it easy" when it comes to sealing joints etc. Plus, we have a choice of material that could be worked with simple hand tools. So 'bye bye' to plywood and heavy saws and other tools, sawdust and noise!
Tools for the Build
Buy a set of basic tools of good quality. You need a Try square and a steel ruler (24 inches), 
a strong box knife with blade lock, a hand drill and a few bits, some emery cloth (50 grit for the 'rough work' and 180 or 200 grit for the fine work) and PVC pipe solvent/cement. Invest in a few pairs of protective hand gloves that have a cut-resistant coating, and always wear your mask to protect your lungs. Exercise extreme care while using sharp tools. The larger boards could be cut on the floor (very stable!), with a cardboard carton piece below to buffer the knife.
Enter Multi Wood
Don't be misled by the name--there is no wood in multi-wood or new-wood, or such like new-fangled "woods"; they are concoctions of plastics and are touted as best material for wet areas like kitchens and bathrooms. They come in an assortement of thicknesses and are sold in standard panel sizes like 8 x 4 feet. (You could sometimes persuade shop owners to sell you 4' x 4' offcuts too, which could suffice for a pair of small boxes. Try to get two thicknesses -- 12 mm and 18 mm, which ought to meet most of our needs admirably.)
The best 'wrinkle' with M-wood is that all you need is a large, sharp knife, lots of patience and care, to cut it accurately into the panels that will go to make up your speaker boxes. Be careful with sharp tools, and make your first cut with minimum force so that a straight line cut is made. Then score deeper a few times; you could now remove the steel ruler and follow the cut easily. Soon the knife blade will cut through. Use a scrap piece of packing board below the cut. Keep the knife straight and score repeatedly, rather than use brute force. It is a technique that you will soon master. Knife-cut edges are smooth--unlike saw cut ones, which need smoothening with sandpaper before they could be glued.
Tricks of the Build
You need to develop certain wood-working skills. The most important is the use of a Try-square (the L-shaped tool) to mark and check right angles in panels and edges. Always check measurements and right angles to ensure an easy and proper build. With M-wood, all you need is am emery cloth wrapped over a small piece of wood (M-wood!) to rub and correct the edges and angles--taking out a few mm of M-wood is child's play, believe me.
Once all the panels are cut and ready as per plan, it is time to start gluing them up in an orderly manner. The PVC solvent/cement is highly acidic and the fumes certainly are unhealthy, especially in closed spaces. So try to work in an open verandah, or near a window, with a desk fan pulling the fumes away from you to the outside. Use the built-in sponge to spread the solvent on both the mating surfaces (careful not to be too liberal and make it run!) and hold the panels together firmly for about ten seconds--enough to effect a basic bond. Where possible, put a small weight on top to hold the bond under pressure for some time. Unlike pvc pipes, this takes longer to set fully and ensure a strong bond. It is best, IMHO, to work on one box partly, leave it aside for a while, and work on the second. This means both your boxes will be finished almost simultaneously. Before applying solvent cement, be sure to check and correct the mating surfaces for any gaps etc. (You could save some of the white "sanding dust" and use it as a filler before applying some solvent--makes a good joint filler!)
M-wood, despite its many advantages, has very poor screw holding ability. So for mounting speaker drivers, we have to resort to nuts and bolts. An easy ploy I adopted was to superglue the nut to a fairly large washer and then stick the washer onto the M-wood panel using either superglue or even pvc cement. Use moderate pressure while tightening the driver, which anyway is advised so that you don't damage the precious driver. Drilling holes in M-wood needs nothing fancier than a simple hand drill. Mounting the speaker cable connectors in the back is not as involved as mounting the driver--simple wood screws will hold the terminal plate securely.
So much for the build "mechanics".
And now onto our projects!
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