As always the I 3C-S received at least a total of 100 hours of burn-in/use before commenting on the sound. The I 3C-S saw minimal changes to the sound through the burn-in process, nothing I would consider major. As for amping, I’ve noticed no huge difference despite it or using the 100 ohm adaptor. I’ve chosen the DUNU mushroom tips, mostly because they are all that fit.

Like most balanced driver IEMs I’ve experienced the DUNU are best described as a detailed oriented IEM that overall has a balanced sound throughout that suits well-mastered albums over modern day masters. The ends of the frequency spectrum are represented in a balanced manner with decent extension, though the extreme lows are lacking. Let’s get into a little more detail though.

The lows extend well with decent presence, that is to say they extend well unless you find yourself listening to a lot of sub-bass intensive music then they are severely lacking. I’m not sure exactly where the frequency drops, but somewhere in the extreme lows they simply disappear. For most genres the bass is represented well, even for hip-hop tracks I found the bass to be adequate, but the bass quantity certainly won’t satisfy those who want a big thump from kick drums or that deep sub-bass for the dubstep wobbles. The bass quality is rather decent though, I found no signs of distortion despite the frequency, unless the headphones were far too loud, which shouldn’t be an issue to many and I found out by mistake. Lastly the I 3C-S do a decent job with speed. They are no Ad2000, but I don’t feel as if the bass is lagging behind.

The mids are the focus of the headphone as I would put the I 3C-S into the slightly mid-forward category, but there’s a huge problem with the mid-range here and it’s that it has a tendency to sound very artificial at times destroying the natural timbre of acoustic drums, vocals, guitars, and pianos, to name a few. I’m not exactly sure what is causing the problem, it may very well be the I 3C-S revealing flaws in the recording, but I will say that even on well recorded masters I’m not fully convinced that I’m hearing real instruments. The instruments tend to have a plastic sound to them, as if the band were using cheap instruments. This isn’t constant, but it’s a bother enough to turn me off from these for most tracks. The mids also have a slight grain to them that is present in any recording. The good news, though, is that sibilance is not a problem here, sure sibilant heavy recordings are exposed, but no more than they should be.

The highs are extended well without being harsh, but they also suffer from being a bit grainy as well, though not as much as the mids to my ears. The highs are well balanced with the mids and lows which is especially noticeable in Pink Floyd’s

Comfortably Numb

during the ending guitar solo, but they do sound a bit restrained at times. Perhaps I’m just used to my Ad2000 which are a bit bright. The highs have good presence, extension, and a decently clean sound from them, which is really all you can ask for at this price range.