Make a simultaneous selector and display for decibels

I'm creating an android app that. I want to create a display for decibels that shows the actual noise captured by the phone. At the same time, I want the user to have an option to select the level of noise at which an alarm triggers. So, I need a display and a selector simultaneously, I don't know if separated, if together... I tried different options.

My first attempt was two concentric circular progress bars, but that didn't allow the user to distinguish which was which, so he had to remember. A typical decibel display (the one you see in every Android app) along with a semicicular bar on top was the second idea but they seem unpleasant together. I also attempted creating a vertical progress bar (so the user associates it with sound) in which the thumb is the number the user inputs and the secondary progress is the actual sound, but it doesn't come out as important. What would be the best option? Thanks.