Concrete Audio Speakers...Speaker Enclosures made out of Concrete ?..

No. They will ring like a bell. And not thick enough. 

So if a speaker is shaped like a bell it will ring like a bell?

It IS a bell. Its a bell with drivers in them. Not a good idea. 

Because they are not thick enough and they are too resonant. You want something that doesn't ring when you tap it. 

If it was so good most companies would do it. Those companies that have done it haven’t been successful.

A concrete wall could be used but not a box.

Its not a question of practicality. They sound bad. 

They do sound quite bad to me. 

WE ARE WAITING FOR SAMPLES FROM JERN JERN http://jernspeakers.com/jern12-xf-loudspeaker/ 

They are unfortunately made of iron so they will ring like a bell. The speaker is even shaped like a bell so not very good design. 
Theres no response curve provided on their site, they have -6db @65 hz which is terrible and are overpriced. Best to be avoided. 

How will the speaker shaped by kenjit sound?

If I had a speaker company my speakers would have to be perfect. No ringing or resonances. Just pure music.