Decoud,

There is nothing wrong in what those guys propose and there is nothing wrong in in-wall to mount drivers in infinite baffle configuration. In fact it very much interesting idea to build a custom room with a strange shape where wall most favorable be shaped for sound formation in this room. However, how it is usually is done is just a sound for lounge audio and for lounge music. You are sitting is bar, crewing sandwidges and drinking mango juice, and trying to convince your girl-friend in 432 times that it is “not good time” for you to marry her. Meanwhile 150 feet from you on the stage a Liberal Art School of Music drop out plays some gipsy tunes on unturned cello, accompanied by drunk friend with Casio keyboard. That is a lounge musical experience and what the regular wall-mounting audio produce is good enough to support it. I do not mean to say that all lounge music is bad – have witness some stunning lounge music events but all lounge audio objective are not really serious. There are zillion reasons why and I think that if you are “knowing next  to nothing about audio” then to discovery those reasons might be a good journey for you.