Apple’s 3.5mm Lightning Audio Adapter costs only $8, and combined with a headphone/microphone splitter, creates an inexpensive way to record audio from an external source onto an Apple device. This comes in handy for mobile recording, and can be used to capture audio from a microphone, mixer, or a portable recorder, and can even be used to capture audio for video alongside the iPhone/iPad’s built-in camera.
Because these cables are fairly inexpensive, they can come in handy in a pinch, and even serve as a useful backup option in place of a dedicated audio interface. We were able to get everything for roughly $17.
What You’ll Need
If you’re using an iPhone 7 or newer, you’ll need an Apple’s 3.5mm Lightning Audio Adapter, as mentioned previously. This adapter contains a stereo digital-to-analog converter, and a microphone preamplifier and analog-to-digital converter. Because the headphone output and microphone input are combined into one connector, you’ll need a splitter to separate the headphone output from the microphone input. The separate headphone output provides the option to listen back to recorded audio without having to unplug the mic￼.
Headphone/microphone splitters for iPhones and iPads sell for as little as $7 on Amazon, at the time of writing. The only tricky part is making sure that you select the right one.
CTIA vs. OMTP
Some microphones for iPhone have 3.5mm connectors with 4-terminal TRRS connectors that you can plug directly into a lightning adapter or headphone jack.
Though not all splitters are compatible with Apple devices. CTIA and OMTP are two different wiring standards for 4-terminal TRRS connectors. Both are incompatible with one other, which means that if you use the wrong adapter, you’ll either get no signal at all, or a weak, distorted signal. Manufacturers who sell these adapters don’t always make it clear whether or not they’re designed for Apple products. Make sure the splitter’s description says that it specifically uses the CITA wiring standard.
For those of you interested, the pin out for CTIA from tip to sleeve is:
Left, Right, Ground, Mic
The pin out for OMTP from tip to sleeve is:
Left, Right, Mic, Ground
The CTIA standard is used on the Apple lightning adapter, and for iPhones and iPads with TRRS jacks. Some smartphones, laptops, TVs and other devices may use the OMTP wiring standard. Unless you’re using an Apple device, you’ll have to research which wiring standard your device uses for its audio connector when purchasing a cables.
Unfortunately, combining a lightning adapter and headphone mic splitter isn’t a one-size-fits-all solution.
It’s important to note that incoming audio signals must be at mic-level for this set up to work￼. If your mixer has an output control, simply turn down the output gain so that it doesn’t overload the mic input. Also note that all incoming signals will be monophonic only, not stereo. This suits voice recording well, but not for music or some instruments. Likewise, the mic input doesn’t have enough gain to drive a microphone, nor does it provide the +48V phantom power required to power a condenser mic. You’ll need an external mic preamplifier with a line output (preferably 3.5mm to connect to the mic splitter).
If you plan to record line-level signals on a consistent basis, try using a line-level to mic level-attenuator in place of the splitter. These reduce the signal level of line level sources to match the input level of the iPhone. It’s worth noting that these attenuators are more expensive, costing about $20 on Amazon, not including￼ the $8 Apple lightning audio adapter. That said, it’s ￼still cheaper than using a dedicated interface or purchasing a dedicated recorder.
For specific tasks, this can work well in a pinch or as a backup recorder. Although if you find yourself using a myriad of special cables and adapters on an ongoing basis￼, you might be better off using a portable recorder or dedicated ￼audio interface.
If you found this helpful, or have recorded audio using these methods￼, let us know your thoughts in the comments below.