Kants Critical position is more correctly described as phenomenalism than as subjectivism.
In other words, is Kants position subjectivism or phenomenalism?
The proper names for these opposite conceptions are of course Noumenalism and phenomenalism.
In so far as subjectivism reduces reality to states of knowledge, such as perceptions or ideas, it is phenomenalism.
Similarly a phenomenalism, like that of Hume, takes immediate presence to sense as the norm of being and knowledge.
But he differs both from Malebranche and from Hume in that he develops his phenomenalism on rationalist lines.