iTunes / iPhone music playback quality issues
Over the past year or so, the playback quality on certain CD's I've burned into iTunes has become terrible. Only on certain harder music like Tool or NIN, although some others are fine. It's so bad you can't even listen to the music. It sounds like there's too much bass or something has come loose inside the speaker.
When playing the music directly from iTunes on my computer speakers or a bluetooth speaker it sounds perfect. But playing on a Bose or Sony bluetooth speaker, in my car on bluetooth or in my car on AUX, or even with Apple earphones it's all the same when through my phone.
My iPhone is a 7 Plus and I'm on the latest versions of iTunes and iPhone software. I've deleted all of the CD's with issues from iTunes and my iPhone and burned them again with no luck. Any ideas?