Mumble is the newest of the three, with supposedly better sound quality and netcode etc., but the feature that sets it apart from its older competition is the plug-ins that it uses to link up with games, allowing you to speak with each other from your positions in-game.
Official site: http://www.mumble.com/
SourceForge page: http://mumble.sourceforge.net/
The first thing to do after you've installed the client is to go into the settings and change what activates your microphone. The default setting is Voice Activity, which opens your microphone based on you making sound. It's by far the worst of the three alternatives. Setting a sensitivity that isn't activated by keyboard clicks or other noise but still catches everything you say is hard, and even if you get it right you sound weird when the first part of your transmission, which was used to activate the microphone, is missing. This method is sometimes called "sensitivity", as in "stop using sensitivity and set a key ffs", and it is never used.
Push-to-Talk is when you manually open and close your microphone by holding and releasing a button. Choose this. Then go to the Shortcuts section and set up a hotkey. MOUSE4 is a solid choice.
The third option, Continuous, keeps your microphone open all the time. This is a must when you're playing with a controller, and very comfortable in general. Push-to-Talk is the de facto standard for good reasons however, so it's important to get comfortable using it (or at the very least be able to). Before I move on to the positional audio, let's talk about volume.
This is third-party software that games have no idea you're using and have no respect for. In other words, it's completely up to you to decide the balance of volume between the game and the voice program. This is crucial. If you set the voice program too high you will soon crave blood every time someone makes a noise, as it completely blocks out everything happening in-game. You will feel like you're 80% on the voice server and only 20% inside the game. And when someone else keeps telling you to shut up because they can't hear anything in-game... well, let's not go there. If you on the other hand set the game too loud, it becomes impossible to hear what anyone is saying, and irritation can build up quickly in the heat of battle when every other line is "huh?" or "didn't catch that" or "you're too low!" or "CAN'T HEAR YOU!!!!!!". Or even "why didn't you tell me?!?!" and "I FUCKING DID!!!!!!!"
First of all you must have everyone's voices at about the same volume, and this is easiest achieved outside the game. TeamSpeak let's the receiver change how loud everyone is, but usually you have to tell people to raise or lower their transmission volume. Once inside the game you want the voices louder than ambient stuff like rain, but lower than crucial information and things which are supposed to be louder than speech. It varies from game to game, but basically somewhere that feels somewhat natural, as that's usually where you can hear the most of both voice and the game at the same time. When you've found a good spot to insert the players' voices, and everyone has about the same settings, it'll be natural to raise your voice trying to talk over gunfire, or go silent mid-sentence when you suddenly sense death lurking around the corner. And now on to the positional audio.
How it works: http://mumble.sourceforge.net/Positional-Audio
Supported games: http://mumble.sourceforge.net/Games
In the lower left corner of Mumble's configuration window there's a box that says Advanced. Tick it. Then go to the Plugins section and tick the box at the top that says Link to Game and Transmit Position. Then go to the Audio Output section and tick the box in the top that says Positional Audio.
Positional audio is now enabled, and if you start up a game and there's a successful link you will be told so in Mumble's chat window. (You can drag and drop Mumble's different windows to customize its layout.) But the default settings are shit so we'll need to change them. Note that what's ideal might vary from game to game, and that all my experience so far is based on L4D. I'll start with explaining what each setting does, since the tooltips make no sense.
Minimum Distance (0.0–100.0 m) = anyone closer to you than this will speak at full volume. We started with 0.0 m, but this made volume drop off unrealistically fast being just a meter away. Setting it to 5.0 m was too high, giving you no sense of distance between players in close quarters. We had it on 3.0 m for most of our testing, but it's currently at 2.5 m.
Bloom (100—175%) = makes things louder. Setting it to 100% made everything too quiet, but I'm not sure how this works yet. We're keeping it at the default 150% for now. (Maybe infernovia can fill in.)
Maximum Distance (0.0–100.0 m) = if someone is further away from you than this you can't hear them. We tried maxing it, but volume scales linearly between the minimum and maximum distances (or does it, infernovia?), so if you set this too high volume drops off way too slowly. And having it on max you could hear way too far. We currently have it at 55.0 m.
Minimum Volume (0–100%) = how much you will always hear the other players. We set it to 0% right away, so that being too far away for communication is actually possible. Using it gimps positional audio into directional audio. It might be useful in some games, perhaps preferable to standard non-directional audio. But using it feels really weird: having a changing direction on a sound that is loud makes you think (even feel) that something is close — and not 500 m away beyond multiple walls. Subject to more testing, but worthless for L4D.
L4D settings:
Minimum distance = 2.5 m
Bloom = 150%
Maximum distance = 55.0 m
Minimum volume = 0%
It's not perfect, and at the start it's disappointing how you can't get it to work exactly like in real life. But it is hella cool, and we've yet to see what it's like with people talking from multiple directions simultaneously. To wrap things up, let's take a look at my Audio Output screen:
Note that I have unchecked the "while other users talk" box. You have to do this if you don't want the game's volume cut every time someone speaks, making it impossible to find a good balance of volume. Basically this feature is for those that have given up on that front, and that it's enabled by default is very strange since it's super annoying even outside of games.
I have also checked the Headphone box without knowing what it does, since I use headphones. I've never played with proper surround sound, so I can't speak to how well one can hear directions with it, but when you're going to be using a microphone at the same time I can't imagine it working out well (it usually doesn't). Normal speakers are completely out of the question in an FPS due to them only giving you something like 30 degrees in each direction, which is to say they lack 300 degrees hearing — any pair of headphones that even barely work is preferable. A headset is ideal, since then one will also have the microphone at a fixed distance from one's mouth, helping with the volume balancing. (If you have a standing microphone you'll have to sit still, lol!)
My volume in Mumble is maxed out. It depends on one's system and everyone's transmission volume (= input volumes, which it didn't occur to us to raise lol), but the game is quite loud, and we lowered its volume to about 10% when we were testing. It's currently set to 20%, but I suspect we'll raise it a bit more. I've more or less turned off the in-game music, but I want it lurking deep in the background so I will be raising that as well.
My sliders for buffering are at the lowest since I've yet to connect to a Mumble server with higher than 10 ping, but that's of course subject to tweaking depending on what server one is using.
