Connecting a Voice Tracker II array microphone to an iPhone or iPad

This entry was posted in Array Microphones on by .

We often get inquires on how to use the Voice Tracker II with iPads and iPhones for enhanced recording range, and for inexpensive conferencing/telemedicine.

There are two “tricks” for doing this.

First, a TRRS splitter is required. This is connected to the 3.5mm jack on the iPad or iPhone and creates separate 3.5mm connections for the mic and loudspeaker. See the photo of such a splitter. Such splitters are readily available commercially.

Second, the output impedance of the Voice Tracker II must be adjusted to match the expectation of the iPad/iPhone. These devices require an input impedance of less than 10Kohm. If the output impedance of the mic in higher than that, the iPhone/iPad will default to their internal mic.

The output impedance of the Voice Tracker II is higher than that, so an adapter is needed in the 3.5mm cable to reduce the output impedance to below 10K.

When the Voice Tracker is connected thru the TRRS splitter and impedance adapter, you can hear the improved pickup range:


Because the Voice Tracker II has built in acoustic echo cancellation, it can be used with iPads or iPhones for inexpensive conferencing. Connect the speaker jack from the TRRS splitter to the ref in jack on the Voice Tracker II, and connect an external powered computer loudspeaker to the speaker out jack on the Voice Tracker II. Provide power to the Voice Tracker II from USB battery, or a USB wall power supply. Then run a VoIP app on the iPhone or iPad.

See the photo below. Note the thicker 3.5 cable to the middle jack on the VT II (the audio out jack). That is the impedance adapter.

If you are using Zoom or Skype for Business as the VoIP App, they have good AECs, so the AEC in the Voice Tracker II is not required.

This reduces the number of cable connections (clutter). You can then connect the speaker jack from the TRRS splitter directly to the loudspeaker. See the photo below.

Bob Feingold