The element copper undergoes the process of oxidation, if it is exposed to air. Copper metal reacts with oxygen, resulting in the formation of copper oxide which appears green in colour. Copper does not react with water, the outer green layer formed after the oxidation of copper is known as a...

I am happy with the ZS5. How do we explain the good sounding result even without a crossover? What other multi-driver iems do not have crossover?

SENNHEISER IE 80 S: HIGH-END EARPHONES TAKE A NEW TURN http://theaudiophileman.com/ie80s/

Klipsch Ovals

Yes, this can be used for ZS5. The picture below show that the white portion just above the 2 pins has been removed for deeper insertion of the pins. Got this cable and is starting to turn green just after 2 months use.

I use Teflon Tape:

Try this: https://www.amazon.com/dp/B015HCLRO8

Thanks. Sharing a screenshot from my facebook fiio page.

Please include an optionional cable without inline control/mic for those who do not need this.

Sennheiser IE80 Headphone Price: $292.87   as of April 8, 2013   http://www.amazon.com/Sennheiser-IE80-Headphone/dp/B006EK9J9 S

Quote:   I agree. Treble is very harsh and sibilant. No amount of burn-in will fix this. Return them ASAP.   The S4 was my first IEM. Got the HF5 and  a reshelled UM TF10  thus  confirming the S4 is "trash".

Quote:   You can stretch the S4's silicon eartips little by little. Use the tip of the pencil to strech. Seems impossible but I was able to make it fit the TF10. 

Quote: I agree. I will never buy a universal IEM again, been very happy with my UM reshelled TF10. The fit and isolation of a custom is way above a universal and the music is so alive.