For the actual 'room' the term Throne room seems to be well established:
throne room or throne hall is the room, often rather a hall, in the official residence of the crown, either a palace or a fortified castle, where the throne of a senior figure (usually a monarch) is set up with elaborate pomp—usually raised, often with steps, and under a canopy, both of which are part of the original notion of the Greek word thronos.
On that page we see examples for lower-than-kings, like Monaco.
A problem with this concept is that in Europe most smaller rulers of that timeframe in most of Europe had to represent their power and money and whatnot with this kind of architecture. But these rather large rooms or halls were not necessarily really where such rulers actually sat all day to — well, rule from the stool all the time? Such accommodations were of course used for audiences, ceremonies, festivities, honours, assemblies of court etc.
One such example of a throne —without a throne room!— would be the Duke's chair in Carinthia in use from 1161 to 1597, similar in function to the Coronation Chair. Obviously, taking power was symbolised by taking seat on that seat, but everyday business was then conducted elsewhere afterwards.
We therefore need perhaps look at the functional aspects of 'a throne room' which are transferable to other rooms and contexts, and therefore give rise to a lot of other names for such a room. The idea that historical monarchs in particular performed almost all of their official functions in a throne room is likely to be a romanticisation in most cases. Many monarchies in the early historical period of inquiry here were operating without having even a proper capital or a residence.
If we consider these differences, then we might discover still quite a lot of examples like in Meißen the Albrechtsburg with its "Great Hall", which was built from 10th century by Margraves and taking its present day appearance in late 15th century under Electors. Similarly, the Dresden Castle features two rooms called properly 'Eckparadesaal' and 'Audienzsaal', although they are alternatively called throne room and new throne room, for the Elector of Saxony, after their apparent functions.