Front-facing stereo speakers are a huge selling point for a lot of people within the smartphone community. Traditional speaker placement usually has it firing down through the bottom frame and this can easily be covered up when you’re holding the device in landscape mode. XDA Senior Member acervenky has created a mod for the OnePlus 6 that uses the earpiece speaker as a second external stereo speaker for the device. Once enabled, audio that would normally only play through the bottom firing speaker will now play from the earpiece speaker as well. This mod requires Magisk so that you can enable the module, and it will work partially on a stock version of OxygenOS. The developer says that you will need to have the NoLimits ROM or Viper Audio installed if you want to get stereo audio working.
Check out the forum thread below for more information about this stereo speaker mod. Also, watch the video below for a quick demonstration. Use this mod at your own risk. Playing excessively loud audio could result in damage to the earpiece.