Vsonic GR07 mkII

Once again, my brother Inks set an arrangement for me, so a Head-Fi user, Flysweep, generously let me borrow his Vsonic GR07 mkII. You guys are truly good fellas.

Unfortunately, I neither have a clue what this IEM is nor who the Vsonic is, but according to the manufacturer's website, GR07 is a studio-monitor flagship model, equipped with a driver which has a bio-cellulose coated on its diaphragm. As far as I can recall, there has been only one earphone with that technology implemented in the history of headphones: A good ol' discontinued SONY MDR-E888. How interesting.

PRO: Very good built quality with an uber distortion performance. This is the lowest I've seen from an IEM. A nice gesture from the manufaturer to ensure users' wearing comfort: Not only GR07's stems are pivotally adjustable, the IEM comes with whole bunch of ear sleeves. The impedance characteric is very stable too.

CON: The polarity is inverted; not a flagship-quality. GR07's spectral balance somewhat reminds me that of SONY MDR-EX1000, IMHO. And obviously, the rated frequency limit of 30,000 Hz is just NOT TRUE.

ON SECOND THOUGHT #1: As expected, once the vents are blocked, the sub-bass gets either boosted, or attenuated. Since this vent prevents the IEM from getting over-pressurized, I would not recommend blocking them what so ever.

ON SECOND THOUGHT #2: Surprisingly, GR07 do not get affected by different insertion depths as much as other IEMs, possibly due to the low acoustic output impedance the biocellulose driver has. Of course resonant frequencies do shift, but overall tonality is quite well preserved.

ON SECOND THOUGHT #3: As mentioned, GR07 is almost free from the electric damping issue, which happens to be very problematic with some IEMs. Even a 100 Ω resistor does not alter the frequency response of GR07 at all.