There are a handful of games for the Nintendo DS that take advantage of the system's onboard microphone. So far, finding a solution that allows you to use headphones as well as the microphone has left you with few options. The Nintendo-branded headset we reviewed attempted to solve this, but some design flaws really held back its true potential. Its most noteworthy shortcomings were the lack of stereo support and the short microphone boom. The latter was an issue primarily for the admittedly small list of games (for example, WarioWare Touched!) that require you to blow into the mic, rather than just speak commands or utilize multiplayer voice chat.
Turtle Beach has improved where Nintendo left off with the release of the Ear Force D2 microphone headset for the DS. Available in black, white, and pink, the Ear Force D2 provides stereo sound and an adjustable boom microphone for voice commands and multiplayer chatting for less than $20. This boom also alleviates the problems with using a "blow command" now that the mic can be situated directly in front of your mouth. If you are not using the microphone, it can be tucked away, out of sight. The attached cord is approximately three feet long and features a convenient inline volume control knob. Pivoting ear pads allow for the D2 to adjust to your ears, increasing the overall comfort of the headphones.
In terms of sound quality, the Ear Force D2 performed well enough. And while the DS is hardly an audiophile device, switching to the headphones mode of your particular game (if offered) can certainly improve the sound. We couldn't test the Ear Force D2 with better-sounding audio sources even if we wanted to--its plug includes the remote nub that's proprietary to the DS and DS Lite, so it won't work with anything else.
The fully adjustable microphone can bend in any way you wish. In our testing with Metroid Prime: Hunters multiplayer, we did find that the optimal location for the microphone is about two to three inches from your mouth. At this distance, the voice quality was very clear and both parties were able to understand each other with little to no distortion.
If the majority of games you play don't make use of voice-oriented gameplay, you can pass on the Ear Force D2 and just stick to your favorite set of headphones. However, if a large percentage of your DS gaming encompasses voice-based commands and online chatting, there is no reason to look any further than the Ear Force D2.