The back of the remote has a small hole that houses the silicon microphone that picks up your voice when you use the headphones for voice calls or commands, but the 360-degree pickup means you don't need to hold the piece up to your mouth to isolate the sound of your voice. Call quality is standard for a pair of wired headphones, and our test call recipient reported no problem maintaining a conversation, even on a busy avenue in New York.
The A-Jays Four headphones come with a hard case that slides out to reveal a detailed instruction manual and four sets of silicone sleeves, making five total earbud covers including the pair that comes already installed. The A-Jays Fours are just earbuds like the ones that come with your iOS device, so the rubbery silicone sleeves are supposed to sit snugly inside your ears. If you want a more isolating listening experience and are comfortable with rubber inserts deep in your canal, check out the Etymotic hf5 series, but keep in mind you'll also pay double the price.
That said, we continue to experience the same fit issues with the awkward circular shape of the A-Jays earbud covers that we did with the A-Jays Three headphones. We found ourselves constantly switching between the sizes, which range from XXS to L, and still couldn't find a comfortable option. We also couldn't wear them for more than half an hour before experiencing discomfort that required slight adjustments. Additionally, the earpieces themselves aren't very wide and sit almost flush with your outer ear flange, so you may experience additional discomfort depending on your ear shape.
If you experience such discomfort with the A-Jays Four earphones, we recommend the Monster Cable Gel and Foam SuperTips that we tested with the Monster Mobile Jamz; they're compatible and provide a better overall fit. As always, we strongly advocate an oval tip like the ones included with the Klipsch Image S4i earphones, although the price jump is significant.
We tested the sound quality of the A-Jays Fours with an iPhone 4 and a variety of different MP3s and came away merely satisfied with the sound quality. As stated earlier, you can get a much more powerful upgrade in fidelity with a pair of in-ear canal earbuds, but the A-Jays Threes are slightly lacking in bass boost. With the iPhone equalizer turned off, the sound design is more suited for loud music like hip-hop, rock, and club hits, whereas jazz and classical fans may be disappointed by its lack of aural definition. That said, the A-Jays Four earphones are certainly an upgrade from the stock pair included with all the iOS devices, and you won't be disappointed if you're making that jump here.