Sound is muffled :(

When ever i plug my m6 into my hifi system the sound seems very muffled the whole mid range just seems to be one big messy sound with some vocals very hard to hear.
I also put the same files onto my w960i phone and they sound alot better, both eq were set to flat, why is the m6 so much worse does anyone else think theirs sounds a bit lifeless ???
What can i do to the eq to fix this /?

Thanks