I just added a Quest 2 GPS and would like to be able to hear the voice commands through my helmet speakers. The problem is I have a radio on this setup already. I would like to combine the two audio signals. Right now I have a Y connector but the audio does not sound that good. It needs to be isolated some how. I did a search and found some audio mixers that would work but they are expensive ($180-225). Is there any cheap way of doing this. I am using 3.5mm mono jacks and cables.