Why concrete? Technical backround
Unlike the body of a musical instrument, good loudspeaker housing should not vibrate, as modern drivers (the actual loudspeaker in the box) today render the full sound spectrum linearly.
But if the housing itself does vibrate due to its construction or materials (wood, plastic), then those vibrations affect performance by amplifying or diminishing certain sympathetic frequencies within the sound spectrum. It is a complicated physical process with a simple and clearly audible consequence:
The music does not sound original, it sounds distorted and unnatural.
Here, the difference with musical instruments is clear. It is desirable that the natural resonant frequencies of a violin body should colour the instruments sound. It is only in this way that timbre comes to distinguish a Stradivarius from other violins. The only sound that should be heard from a good loudspeaker is the input signal, nothing more and nothing less.
Concrete is:
Very heavy.
Its weight and high density prevent it from vibrating.
Irregularly structured.
Vibrations can not spread.
Castable in any form.
It is possible to cast a very robust loudspeaker housing with one single pour.
We manufacture the housing of our loudspeakers made from high-strength concrete. By means of a special casting process, the housing is cast out of one single body with all sides closed and sealed.
The monolithic structure has no internal walls in parallel and is lined with different layers of sound absorbing materials to prevent any possible reflections. The result is a resonance free housing that lets the driver function as it is intended.