Is it legislated to call people to congregational prayer using loudspeakers?

It is not legislated to call out via loudspeaker to gather worshipers for the funeral prayer, whether by saying "prayer is gathering" (الصلاة جامعة) or "prayer for the deceased" (الصلاة على الميت); because it is an innovation. The jurists disliked shouting in the mosque or at its door to announce a death, unless it was in a low voice. Furthermore, the call "prayer is gathering" (الصلاة جامعة) was only reported for the eclipse prayer, and it is not correct to make an analogy to it.