Grupy_Mike, thank you very much for your good advice. Only now I see that there are on the original schedule from one maker that it says "used an amplified speaker".
At the second in his schedule is not indicated, but in re-reading his tekst is there anywhere "a speaker from 8 ohm 0.5 W. This accidentally overlooked.
With data from a third party, with my custom code that I use, there was nothing of data or schema. But I get a mail that he is also a speaker of 8 ohm 0.5 W has used.
Hachey, also thanks to you, for a proper response.
So my solution is near, last night have done the following:
Have ordered amplifiers both photos and also speakers from 8 Ohms 0.5 w. In this way I can use all speakers that I have in other projects.
Case closed for me.