HD558 is a full-size headphone, your phone doesn't have enough power to drive them correctly from what you describe. In this case we would add an external headphone amplifier such as FiiO E06, ($30) Topping NX1 ($40), either of these choices will provide more power / volume for your Sennheisers. Alternatively, you could consider a new player all together like FiiO X1, X3, DX50, DX90. But adding a little amp will correct your current volume issues.
11/20/14 at 3:51am