It depends on the audience you are addressing

[Bobbert]

I’m unsure how to say:
It depends on the audience you are addressing.

The first thing that comes to my mind is:
Depende del público al que te dirijas.

But then I question if it should be:
Depende del público a que te dirijas.

And now I’m questioning whether it should be said in the indicative:
Depende del público al que te dirijes.
Depende del público a que te dirijes.

Which is most correct.

Do I need “a que” or “al que”? and why?

Is the indicative or subjunctive needed? and why?

Input with explanations is very much appreciated.

[Rusty]

Giving your opinion about something over which you have no control is subjective, which calls for the subjunctive.
The article is used to refer back to the object.

[aleCcowaN]

Depende del público al que te dirijas.
.
Perfect!

There are many kinds of public and you address one at a time, which one? It all depends... who knows? hence subjunctive

If you say

Depende del público al que te diriges, [something folowing it up]

it sounds like you're teaching a lesson or explaining some kind of technical protocol.

[Bobbert]

Thanks, Rusty and aleCcowaN. I'm happy to know that my first attempt was the correct translation.

A further question:
Could I have chosen "al cual" instead of "al que" in this sentence?

Depende del público al cual te dirijas.

[aleCcowaN]

Could I have chosen "al cual" instead of "al que" in this sentence?

Depende del público al cual te dirijas.

Yes. And also "a quien te dirijas".

I'm not aware of any rule that favours one choice over the other two.

Al que ----> suggests a wider variety
Al cual ----> suggests fewer choices, as if, for instance, we're talking about kinds of public.
A que ----> humanizes it (singular, because in Spanish "public is" the same way "people is")

[Bobbert]

Thank you, aleCcowaN. That clears it up for me.