First, to the sound. The CX 300 sound slightly differentiated, that is, the bass is more accurate (not quite as kräfig as in EP 360), the voices sound more natural are more present and instruments distinguish good. The surround sound is adequate.
EP 630 have a warmer sound. Bass is always and everywhere. Sometimes a bit too much, because then the voices and instruments can be pressed at bass intensive music pieces in the background. Voices and instruments are still all there, but sometimes you have to make a little effort, these to hear this bass carpet. Ambience is also sufficient.
The Cable. When CX 300 very thin. Somewhat inflexible. The kinks it had from shipping, it has today. Carried it looks like evil snake by the neck. Cable (must be installed behind the neck) by the asymmetrical cable routing thereby somewhat longer than the cable EP 630. Audible noise cable in motion by, for example, rubbing against clothing while wearing are larger than in the EP 630 connector is angled. No gold-plated plug.
In EP 630 bit rubbery, like vertüdelt during storage. Slightly thicker cables. Cable falls beautifully, no kinks. Carried blameless. Cable is symmetrical, is front worn on the chest. Less cable noise while wearing, but with soft music and much Bewebung always present. Plug straight. Gold-plated plug.
Volume. EP 630 are louder. For the same volume when Sennheiser something must be turned on volume control (eg the MD player Sony RH 1 from 20 to 24 on the volume control)
The silicone caps for the ears with both listeners 3 sizes to choose from. The EP 630 when an idea are larger and a bit more solid.
General. In Ear Earphones something specifically. These must be gestecket in my experience quiet little deeper into their ears in order to utilize the full spectrum of sounds. You have to like. Also you have to necessarily take the time to determine the correct size of silicone essays (takes 5 min.) The receiver must in ear quasi complete airtightness. Effect: outside sounds are perceived very eingeschrängt. May be a blessing or a curse. Is the essay gewält too small, the sound is thin, tinny and without bass. Since then you have your own fault.
Thus, the EP 630 plays louder, he saves the battery when moblilen devices. The occasional exuberant bass can keep the equalizer in the fence if necessary. By the straight plug on EP 630 and the cast. Shorter cable he is me better for use on mobile devices, if it is to be plugged in to the remote control (the remote control is ?: the new CX 400 Sennheiser seen?) The CX 300 can be better connected directly to the device due to the angled plug. The risk, which is the cable overstressing the device in your pocket, is slightly lower.
It concerns with both receivers is relatively sensitive products with regard to the input impedance. This means that the new acquisition should tend to the noise, which is by the players and not the handset.
Conclusion: The Sennheiser with the cable of the Creative would certainly be the happier combination. But, something is always ... Both listeners sound is generally much better than the supplied handset with most players. I recommend, therefore, always the good old gut decision!