Practically all high end equipment has absolutely no EQ, Tone, or Treble / Bass knobs because the cleanest route is almost always the best. However, in consumer products - including computers, and especially phones - there is a fashion for having "big bass" - at the expense of the rest of the audio spectrum, so it may be worthwhile adjusting your EQ settings. But firstly IE8's of course have their own bass setting, and as you may have read, most of us like to set this near the minimum (anti-clockwise) end of the adjustment screw because IE8's are also designed to be capable of producing excessively powerful bass to meet this modern trend. It can take some time to get used to listening with the bass set very low on the IE8's but once you do, you will hear all the rest of the music more clearly and wonder why you never did it before! It may then be simpler to simply adjust the screw to suit either your phone or your computer - but of course it will wear out eventually, so some computer EQ may be the best option.
Apologies if you already have the IE8's bass setting low.
I don't think the burn-in will produce the sort changes in SQ you are experiencing, although others with more experience may disagree... If IE8's really require hundreds of hours of burn-in time as some people reckon then I may be still burning mine in!
As far as the details of what may be wrong with your Mac, you may need someone else to give help or suggestions because like I said, I don't do macs! Just a thought though, do you have a USB DAC / amp (or a friend with one
) because if the sound is fine coming via USB then you may just have a dodgy connection on your headphone or line out jack (depending on what you're using). Try gently wiggling the headphone plug when it's plugged in to your Mac, and if it makes more of the same type of distortion sound then you've sussed it and need to get a new socket fitted.
Hope that helps.
