Can I use a splitter with Mic-Lock SoundPass to attach a mic and a speaker?Updated a month ago

No. A splitter does not let you use a microphone with any Mic-Lock product, including SoundPass.

Here is why. The Mic-Lock physically blocks the microphone signal from reaching your device. A splitter plugs in after the Mic-Lock, so it has no signal to split. The mic path is already cut upstream.

What does work with a splitter on SoundPass:

A 3.5 mm speaker. Audio output passes through the SoundPass jack normally.

A second pair of headphones for shared listening.

What will not work, no matter what you plug into the splitter:

A microphone of any kind. The mic input is blocked by design.

A headset mic. Output audio plays, but the mic stays off.

This is how the product is supposed to behave. Mic-Lock exists to guarantee that no microphone signal can ever reach your device while it is plugged in.

If you need to use a mic, unplug the Mic-Lock. There is no workaround that keeps the Mic-Lock in line and lets a mic function.