I'm not sure I understand how or why both of these conditions are necessary for free speech. You talk a lot about the dominant world view, and how minorities get drowned out, but the truth of today's world is that we don't have any public (I mean that in the sense of government, not a private corporation) place, free of moderation/censorship where everybody (how you choose to interpret that term, I leave to you, whether it be citizens, humans, or people from a specific group) can voice their opinion in an intelligent manner without fear of coercion (the free speech side) or attack (the safespace side).
Our largest "public" (in the sense that the internet allows for them to exist) forums are owned by corporations (Facebook, Reddit) with explicit goals of increasing user activity. This means that they are heavily moderated and there are limits to what you can say.
I've gone on quite a tangent, but I guess my argument is that we lack the space for intelligent unmoderated discussion period. Before we decide which half of the space we're missing, I think we need an open forum for dialogue on the scale you're talking about. Once such a place exists, we can discuss whether it needs sections which are more heavily moderated to allow for the minority voice to be heard, or less moderation so that there isn't fear of censorship.
In the lack of the existence of such a space, I believe it is a contrived argument you are making. We don't know whether such a place would inevitably lead to only the lowest common denominator "being heard", and minorities being left out. Besides, people seek to have their opinion reinforced, whether they be from the majority or minority, and you cannot force either to listen to the other. >>908
I agree with you. You cannot force people to listen to you, and people already look for echo chambers. Even if we assume the existence of this space, people are free to ignore whatever they please and accept whatever they want. Being drowned out is no reason for silence.