It takes a lot of science and a lot of magic to make a good pair of speakers. From hard calculations with Thiele/Small parameters to ideas like ‘transparency’ and ‘presence,’ a lot of decisions make up a good speaker design.
One important factor is the material that you use for your enclosures; concrete has some distinct advantages structurally, acoustically, and aesthetically. It is very stiff and heavy—great for supporting the speaker drivers without changing their vibrational dynamics. It also damps out vibrations well, so it doesn’t contribute unwanted rings and unpredictable tones to your sound reproduction. Equally important for something that sits in plain view all the time, it has a unique and interesting visual appeal.
So dust up on your concrete mixing skills and lets get to work!