I recently purchased a Samsung Galaxy S4 and I really love the phone. However, there has been one nagging issue with my phone that is really bothering me. I listen to mp3s, podcasts and use the radio application on my phone heavily. When using the phone with my audio applications, I noticed a heavy buzzing from my 3rd party earbuds (Monster Immersion iSport in-ears) when I increased the volume to a louder setting. Initially, I thought this was an issue when I transferred my mp3's to my SD card and re-did the entire process. Same issue. After a few weeks, I noticed a few articles online by searching "galaxy s4 audio clipping" that explained exactly the issue I was having. It seems there is an issue with some Qualcomm powered S4's and third party earbuds... which is ridiculous. I tried the stock earbuds that Samsung provided (and fall out consistently when I try to run/jog and I have no issues with them). There is a thorough investigation of the issue here - http://forum.xda-developers.com/showthread.php?t=2258831&page=33
What options do I have with Koodo as audio is an important experience with my cellular phone and I have never had any issues with third party earbuds with any phone I've previously owned. Thanks!