Hello i want to make volume controller for 2 speakers. The idea is that i will connect device that is playing audio to arduino using 3.5mm jack, arduino will act as potentiometer and will output the audio signal to the two speakers. Is this possible with arduino? If yes what do i need for this to get this working. Thanks
The problem with speakers is the power level is too high for regular potentiometers. Usually the best method of doing this is to build an amplifier so that you can use a regular potentiometer or digital potentiometer on the input of that amplifier.
But first try to search for a digital potentiometer or fader suitable for your power. There may be one.
Yep thats what i thought. Building an amplifier is probably the easiest way for this project. Thanks 
no need for the arduino here... this is in the analog realm. amplifier, filters and whatever you want. You can even do signal processing by using analog circuits.