TRRS is a type of audio cable that stands for Tip, Ring, Ring, Sleeve connectors. It follows two standards, which are CTIA and OMTP. The main difference between the two is that their ground and microphone rings are switched. They might seem like the same but when you try to use Apple earbuds on your Xbox Controller, you’ll end up with horrible feedback because CTIA isn’t compatible necessarily with OMTP or even fellow CTIA connections. To be more specific, Apple headphones use CTIA TRRP connectors while the Xbox controller has a CTIA or OMTP port depending on the vintage of the controller.
Apple also uses a non-standard microphone and control signaling method though, so that might explain the further discrepancy despite its use of the CTIA standard. Regardless, in the debate of CTIA vs. OMTP, which one is better?
Three Types of 3.5 Millimeter TRRS Connectors
The important thing about the 4-channel 3.5 mm TRRS connectors for smartphone headsets that you should realize is that they’re three types of them and they’re incompatible with one another because they switch up ground with microphone rings. Technically, it’s two types for CTIA and OMTP, but a third type has emerged due to Apple shenanigans.
- What is the OMTP Standard? The OMTP standard is the second most common arrangement for TRRP, with CTIA currently leading the pack. With it, the signaling connector or ground is next to the sleeve while the microphone connector comes through the second ring instead. This is in reverse of the CTIA or AHJ arrangement, leading to feedback or the signal simply not working when you plug an OMTP headset on a CTIA smartphone. OMTP is mostly used by older smartphones such as Nokia, OnePlus One, and old Samsung model cellphones.
- What Is the CTIA Standard? The CTIA connector is linked to the organization known as the Cellular Telecommunications Industry Association (till 2004) or Cellular Telecommunications and Internet Association (after 2004). The CTIA standard for TRRS is also known as AHJ or the American Headset Jack standard. Here, the signaling or ground connector is on the second ring while the microphone connector point is on the sleeve end. Most newer cellphones and smartphones use the AHJ or CTIA arrangement.
- What Is The Apple CTIA Standard? The third standard or arrangement of TRRP is the Apple CTIA standard. In an effort to make their headphones exclusive to only Apple products without an adapter, their CTIA connector arrangement is similar but has a nonstandard control-signaling microphone signaling method. This has led non-Apple products to not work on Apple products or vice-versa despite using the same CTIA standard.
- Compatibility Issues Explained: The most common issue for the incompatibility between CTIA/AHJ devices to OMTP devices is what they’re connected to (the port or pinout) and the number of conductor points on the headset, earphone, or audio peripheral. However, their signaling arrangement can also lead to feedback, as in the case of the Apple earbuds linked to a Microsoft Xbox controller’s OMTP/CTIA port (since Apple CTIA to other CTIA doesn’t work properly either).
- CTIA/AHJ vs. OMTP Applications: CTIA is used by the latest Nokia phones like 1st Generation Lumia, Blackberry, LG, HTC, Microsoft (Xbox One controller and Surface), latest Samsung, Sony (DualShock 4), Jolla, most Android phones, and Apple devices (although their CTIA is nonstandard and won’t work with other CTIA devices and peripherals). Meanwhile, OMTP is used by One Plus One, Sony (PlayStation Vita), old Sony Ericsson models ( 2010 and 2011 Xperias), old Samsung models (2012 Chromebooks), an old Nokia (also 2nd generation Lumia onwards).
- The Results of Incompatible TRRP Plug-Ins: Let’s say you plug your old-school OMTP headset from your old Nokia phone into an AHJ or CTIA phone jack on your newest iPhone or Android smartphone. The results aren’t particularly devastating but you will get a less-than-ideal connection when compared to simply using a compatible CITA peripheral. Usually, the audio out will end up very quiet or outright inaudible. If you want to press the issue, you can avail of an OMTP to AHJ converter.
- To Convert or Not to Convert: If you’re going to plug your TRRP OMTP cellphone peripheral into a more modern smartphone, a converter is required for them to properly work. However, this adds bulk to the headphone or earphone, which kind of defeats their purpose of being mobile or compact. The converter or adapter might also not work reliably when linking up something with remote control function due to the extra dimension of wireless connections. It’s better to go CTIA only, Apple only, or OMTP only connections when push comes to shove.
- What’s the Deal with Apple’s CTIA? Apple wants Apple devices to only connect to their propriety peripherals and vice-versa. No third parties allowed as much as possible. This means that their nonstandard CTIA signaling and control method for headsets is exclusively made for iPhones. You’ll need a converter or adapter in order to control devices and peripherals that use the Apple CTIA standard the same way Thunderbolt and Lightning aren’t exactly or at all like USB-C, Mini-USB, or Micro-USB, and the like.
- The Results of Incompatible Apple CTIA Plug-Ins: The one-button control and audio out of Apple or iPhone headsets work fine on a CTIA, but the volume controls and audio-in for the microphone won’t work at all. Otherwise, you might even get feedback, like in the case of Apple headphones hooked up to an Xbox controller. Some headset makers produce dual version products with wider support, such that it supports CTIA in general but can convert itself to Apple CTIA. However, those can end up hit or miss. Converters are also hit and miss.
Conclusion
Modern smartphones typically use headsets with four-conductor points/bands on the TRRP connector. These connectors typically use two channels for stereo audio out, one for the microphone, and one for signaling or ending the call. With that said, TRRP is divided into 3 standards—AHJ/CTIA, OMTP, and CTIA (Apple).
OMTP is an older type of TRRS used for cellphones and early smartphones. CTIA or AHJ is the current standard for anything that’s not Apple-related. Apple also makes iPhone-specific headsets and audio accessories under the CTIA standard, but they’re practically OMTP when hooked up to non-iOS devices. If you’re not using Apple devices it’s best to avoid any iPhone-specific accessories as much as possible. It’s better to go for AHJ for newer phones and OMTP for classic or vintage phones you’re still using.
References:
- “3.5 mm TRRS plug confusion (CTIA vs OMTP)“, Reddit.com, January 17, 2018
- “How to differentiate CTIA (AHJ) vs OMTP standard TRRS by look?“, Audio Science Review Forum, April 4, 2020
- “Phone Connector (Audio)“, Wikipedia, November 5, 2020
- “Smartphone Headset Standards: Apple iPhone, AHJ (CTIA), & OMTP“, Headset Buddy, March 24, 2020
- “CTIA“, Wikipedia, November 7, 2020
- “Open Mobile Terminal Platform“, Wikipedia, November 7, 2020
