Awei ES-Q5

Left Channel and Right Channel:

As you can see, there is not only a plethora of bass but the channel balance is also very weak - one side is much warmer and bassier than the other. This is due to massive production tolerance and slightly differently sized vent holes (closing the vents on both sides leads to a relatively good channel matching).
I never bought a 2nd pair so I have no idea whether I just got a bad unit or if production tolerance is really that bad.