A few months ago when I was starting voice lessons, I decided to start looking into a way to record the lessons for future playback. While I could have gone with a dedicated voice recorder, I decided that I already had a great tool for recording audio: my Nexus 5 phone. After playing around with a few voice recording apps, I decided I wanted something a little better, and so I decided to purchase the iRig Mic Cast from IK Multimedia; a small microphone that plugs into the headphone port of an iOS or Android device, and which claims to offer better quality.
For those who have not heard of IK Multimedia, they have been producing software plugins for studio use for quite some time. SampleTank, Amplitude, and the T-RackS Mixing & Mastering plugin are a few such products. A couple of years ago they started realizing that musicians wanted something a little more portable. Thus, the iRig line of products was born. What started out as an adapter to connect a guitar to an iOS device (iRig) has now blossomed into several other products such as a keyboard (iRig Keys), MIDI Interface (iRig MIDI), and the iRig Mic Cast; among others.
Before talking about the iRig Mic Cast in detail, you'll notice I specified iOS devices, instead of smartphones and tablets in general. The reason for this primarily comes down to one thing: latency. As part of the Core Audio API on Mac & iOS devices, manufacturers have a way to deal with real-time recording. Unfortunately, this is something not present in Android. This is the main reason you don't see a lot of audio creation apps, or accessories to assist in recording and producing music on Android devices at the moment. This being said, the Mic Cast does indeed work with Android devices, as latency isn't really an issue for its primary purpose (recording voice notes).
There really isn't a lot that comes with the Mic Cast. You get the microphone itself, a small stand to rest your phone on while recording, and an instruction manual. IK Multimedia does offer a voice recording package called iRig Recorder that is available in both the iTunes & Google Play Store, though other apps will generally work as well. I had some stability issues with iRig Recorder on my Nexus 5, and eventually settled on a program called RecForge II to handle audio recording.
On the Mic Cast, there is a Hi / Low switch for adjusting the sensitivity, along with a standard 3.5mm jack for monitoring the input from the microphone. For iOS devices, this does provide realtime monitoring, but due to the limitations mentioned above on Android devices, there was definitely a noticeable delay on Android; making this feature almost pointless. Again, not a fault of IK Multimedia, but rather the Android OS itself.
The size of the Mic Cast is both a blessing and a curse. On one hand, it's unobtrusive when plugged into a smartphone and takes up very little space in a pocket. On the other hand, it's also easy to misplace if you lay it down somewhere! It would have been nice if it came with a small pouch to store the microphone when it's not being used.
Of course, looks aren't everything, and the most important feature of a microphone is how it sounds. Thankfully, the Mic Cast does a fairly good job in this department; easily providing clearer & cleaner audio than the built-in microphone on my Nexus 5. I've attached some audio samples to illustrate this. The built-in mic on the Nexus 5 tends to produce a hollow / echo-y sound, while the Mic Cast is more pleasant to listen to.
Bottom line, if you are looking for a basic solution to record voice, and want something a little better than the mic on your phone, consider spending $40 on the iRig Mic Cast. It isn't going to replace a bigger mic like the Audio-Technica AT2005USB I use for podcasting, but then again it does offer a much more portable solution for on-the-go recording purposes.