I think he is just going for big sound. not quality, some people just don't care, I have a friend of mine that has these god awful sounding "sound design" rack system {not really a rack, its all one piece} like you would get at kmart from the 80's, he said he bought it brand new in the early 90's, it has a record player on top dual tape deck, graphic eq, lol.. Its just terrible, looking, sounding, everything about it, but he has it in his parlor and uses it for music, he has a really nice home too, his wife hates it and said he could replace it with what ever he wants but he said he bought it for $99 and it still works so its not going anywhere.... He swears it sounds as good as my 1200w 2.2 system, lol and I always say "maybe to you"....
But anyway, I think if you make a new front baffle the speakers he made would be fine, maybe a pair of 6.5's with a nice ribbon tweet and a pair of 12" subs in each one.. or go full out with 50 tweets and 15 6.5's all the way up... I have a feeeling this was a tight budget speaker, it looks like he spent under $500 on materials... To you and me he would have been much better off with a pair of tri trix as far as sq goes, but to him, Im sure he loves these speakers..