If you haven’t read about it elsewhere on iLounge or experienced it for yourself, here’s the news flash: Apple’s iPhone has a recessed headphone port, sunk several millimeters below the rest of its metal top surface. Consequently, if you own pre-iPhone earphones made by any company except Apple, there’s a very good chance that they won’t physically connect to the iPhone, so you’ll have two options: buy new earphones, or buy an adapter.

Since its release in late June, we’ve tested a total of five different headphone adapters for iPhone: Griffin’s Headphone Adapter for iPhone ($10), Belkin’s Headphone Adapter for iPhone ($11), Shure’s Music Phone Adatper MPA-3c ($40), Monster Cable’s iSplitter 200 Headphone Jack Splitter ($20, iLounge rating: B+), and Griffin’s SmartShare Headphone Splitter ($15, iLounge rating: A-). All of these accessories fit iPhone’s headphone port and enable you to connect your favorite old earphones without a hassle.
From there, they differ. Belkin’s Headphone Adapter is matte dark gray and semi-rigid, standing straight out of your iPhone’s headphone port unless you push to flex its center.
Griffin’s Headphone Adapter comes in glossy white or black with gray accents, and has a length of fully flexible matching cable in its center. The Griffin versions bend slightly under their own weight, and loosely when you connect a pair of earphones to their tops. Both can be used with iPhone regardless of whether it’s inside or outside of a case.
SmartShare and iSplitter 200, which were reviewed on iLounge prior to their iPhone-fitting redesigns, and re-reviewed for iPhone, accomplish the same goal with two twists. They actually transform iPhone’s single headphone port into a double headphone port for two-person simultaneous listening, and give each user a separate physical volume control.
Other than the $5 difference in price, the only major difference between SmartShare and iSplitter 200 is that Monster reshaped the prior version’s bottom to fit iPhone, and Griffin simply added a Headphone Adapter to its prior SmartShare package. Consequently, SmartShare gives iPhone users two ways to use their old earphones, a great deal for the same $15 price Griffin used to charge just for the SmartShare splitter alone.
As between the Griffin and Belkin headphone adapters, we’d give a slight edge to Griffin’s design. Though only a dollar less expensive, and still not especially well-priced as a $10 accessory for something so simple, its flexible center felt better with our earphones than the more rigid Belkin design. We preferred Belkin’s thinner top connector, but not enough to offset the adapter’s center.