As there is no accepted industry-wide standard for 4-Pole TRRS plugs & sockets, many manufacturers have developed their products with different pin layouts (eg: Nokia, Android and Apple devices). This adapter converts freely between the CTIA and OMTP standards on 4-pole TRRS accessories, with a convenient right-angle design, allowing you to use hardware which would otherwise conflict.
The 4-Pole problem
Unfortunately when the 4pin connector was added to the 3.5mm design, a lack of standards for this implementation resulted in different brands and industries segments, wiring the pins in different ways. Basically, a 4-pole TRRS cable or adapter needs to get the Left & Right Audio, Ground + Mic signals from one device to another. However without a uniform approach, this means the wrong signal might be going to the wrong wire during transmission. With that said, the CTIA and OMTP standards are the most common, and conver 95% of all TRRS connections. This adapter will switch the wirring internally between these two standards.
TRRS is such a headache that we've dedicated an entire blog to it - read our In-Depth TRRS Explanation here - but the short story is that there are two common wiring types when dealing with 4-pole stereo headsets: The CTIA standard, arguably the most common for smartphones and gaming consoles, and OMTP, a less common standard used on older Nokia and early Android handsets. Having miss-matched equipment means your mic doesn't work!
Fortunately this simple little adapter swaps over the Sleeve and Ring terminals, effectively adapting between standards. You can go OMTP to CTIA, or CTIA to OMPT. This will get you going for voice while keeping stereo audio untouched.
The CTIA/OMTP standards issue is not exclusive to smartphones, either. With the Xbox One and PS4 both using the 3.5mm TRRS standard for their headset connections and accessories, it's easy to purchase a miss-matched headset or be forced to buy a new pair when your old faithfuls are perfectly good.
Connect one of these adapters to our TRRS Audio/Mic splitter cables for even greater compatibility with PC gaming headsets on a wider variety of devices.
Apple Note: Apple hand-free kits and earbuds with an inline microphone for phone chat on Apple products are not compatible with any other equipment because of the way Apple uses the Mic and Ground lines for call accept/cancel and media controls. This adapter is not able to convert iPhone earbuds for use with non-Apple devices.