I've been using my speaker for Netflix and YouTube and it's plenty loud and clear. It's louder/better than my S6 Edge that I previously had. Can hear it over our living room sound bar that my father plays at high volumes.
I don't have tinnitus, but I'm very sensitive to high pitch noises. I.e. I hear sounds that most people my age or older can't detect. Thus, bright treble kills me. At its highest volumes with headphones I find the treble to be a bit overwhelming. I'd rather the mids came forward a bit more, but this is at max volume which I rarely ever use. I often listen at 50-75% with headphones and at that volume it's relatively warm and well balanced. It's when it's pushed to max that it becomes overwhelming, so avoid that if possible, sunking101.
For reference, I'm a bit of an audiophile and had phones like the HTC One with dual front facing speakers. Other phones hat have since made the attempt haven't come close, and from recent usage the iPhone series from the past year have gotten it right with mono speakers. Stereo audio is only better when the drivers and tools operating the speakers are of good quality, otherwise it's just noise to me.