A stereo headset is a great accessory for the HTC EVO 4G. A premium pair like those by Ultimate Ears and the V-Moda Vibe Duo combine fantastic earphones for media enjoyment, a microphone for talking on the phone, and a multi-function button to control media and answer/end calls.
Although you would think that using a stereo headset is as simple as plugging it into the EVO's headphone jack, this isn't always the case. Sometimes it will seem that you can only get limited functionality from the headset's multi-function button (usually just media control), which makes it much less useful. The good news is that a simple change in the settings is often all it takes to enable complete functionality.
When you first plug a stereo headset into the EVO, you'll see the headset icon appear in the status bar. This is encouraging because it means that your phone recognizes the earphones, but sometimes you'll find that the multi-function button can't be used to answer/end phone calls while you're listening to music.
Legitimate compatibility issues are certainly possible, but they're unlikely with quality headsets. So try this:
- Press the Menu button.
- Tap Settings, then Call.
- Tap TTY mode. By default, this mode is turned off.
- Select TTY Full, TTY HCO, or TTY VCO.
Now when you plug in a stereo headset with TTY enabled, you'll see this icon in the status bar:
TTY is actually an accessibility feature that can slightly reduce call quality, but sometimes it's the only thing that makes a stereo headset work with the EVO as advertised.
For example, with my Ultimate Ears SuperFi 5vi, I couldn't answer/end calls on the EVO when TTY was turned off. When I turned it on (Full, HCO, and VCO all work), the multi-function button could be used fully, allowing me to single-press the button to answer/end calls and pause/resume media and double-click it to advance to the next track. Call quality didn't sound degraded to me or the person on the other end of the line.
Some stereo headsets will work just fine without TTY enabled, but for those that don't, TTY could help. It worked for me!