Hi,

I'm flying allot and I'm trying to find a way to use my Bose QC20 earbuds during my flights with my aircraft so I can listen to both my music and the airplane Audio. I'm planning to make a microphone in the future if this project work well but for now let's just try to make the listening side of it.

I'm currently looking to mix 2 inputs to one output).

Input #1 : Audio coming from my aircraft's headset jack PJ-055.
Input #2 : Music from my iPhone 3.5mm jack

Output #1 will go into a 3.5mm female jack that my Bose QC20 earbuds will plug in.

I'm quite new to this and I made some research but I'm still not quite sure if I missed something so feel free to correct me if I'm wrong.

The Output #1 is my QC20 earbuds which to my understanding has a Low Impedance.
The Input #1 is my airplane audio from the headset jack which is made for aviation headset with High impedance.
The Input #2 will be my iPhone 3.5mm jack which is made for consumer headset with Low impedance earbuds.

My goal is to make a circuit that will merge both input and allow me to control the output volume with a logarithmic (Audio taper). What are the challenges that I have to face with the impedance difference of my inputs? Is there a way to build a electrical circuit that doesn't need a external power source like a battery and simply use the inputs power?

Thanks!

 

You can match impedances using small audio transformers.

The only other solution I can think of is a small battery powered stereo headphone amplifier. They are readily available at low cost.