So I just recent switched from a Galaxy S4 to an S6. I drive an older 2003 Subaru that has never had an auxiliary input, and I have always been too cheap to upgrade the head unit. So for years I have been getting by just fine with a cassette adapter and plugging it into my phones headphone jack. It has always worked great for music, but in addition it works pretty well for making and taking calls. The audio comes through my car speakers while still using the phones microphone for my audio. That way I can talk hands free, and since the audio plays through my speakers I can get it to a volume that the speaker phone cannot. This has worked great for the last decade. It worked great on my old Samsung Jack, my Motorola Droid, my HTC, and most recent my Samsung S4. Now that I have switched to the S6, when I make call through the cassette adapter the caller on the other end is hearing themselves echo really loudly to the point it is unbearable. Why? What has change from the S4 to the S6? Is there an audio setting I need to change?