Hi everybody! I'm new here.
I've been reading this forum as a resource, and all of your opinions (but especially ClieOS and ljokerl) have been extremely helpful in guiding me towards some IEM purchases. I started with the Brainwavz M2 and loved them; most of the reviews were spot-on. However, as fun as those were, I wanted something a bit more neutral and with a bit more bass extension... I found I could EQ a bunch of sub-bass into the M2, but they didn't really offer it on their own, and the mid-bass to lower-mid hump (about 100-300 Hz) was a bit too prominent for my taste.
So after reading further reviews, I decided to try the Brainwavz R1 despite reports of recessed mids. The bass extension was phenomenal and the mid-bass hump slightly less pronounced, but it was a bit too much of a bass monster for my taste... and more notably, the upper mids (around 4 kHz) were extremely peaky and resonant... I was surprised that this attribute wasn't noted more often. Lucky for me, this particular piece had the right speakers wired with the polarity reversed, so it was easy to return them.
Next up was the Brainwavz M5. By all reports, detail, separation, refinement, etc. should have been improved over the M2, but I found quite the opposite. I do love the bass extension, which reminds me of the R1, but the mid-bass hump is just as bad or worse than that of the M2. What's more, depending on which tip I use, I get an extremely shrill peak somewhere between 4 and 6 kHz requiring 6-8 dB of EQ to remove (similar to the R1), and it tends to overshadow the rest of the midrange and treble, completely destroying the clarity of the sound. Also, there are several holes in the frequency response of the treble (a big one around 8-12 kHz makes everything sound kind of hollow and weird, especially with the upper mid/lower treble peak previously mentioned).
I picked up the Sony MH1C after that, and they sound great, exactly as described by many. As I said before, I also really like the M2 and found the reviews to be accurate. I understand hearing is subjective, but no review describes anything even close to what I hear with my M5, which are nearly unlistenable for me as they are. I really WANT to like them, because the build quality is fantastic, the sensitivity is great (they require very little power to drive), the bass extension and impact are lots of fun, they're incredibly comfortable, and they stay in place really well.
I guess I'm wondering if there's something wrong with my ears, if maybe I have a defective unit, or if anyone else has had similar experiences with these IEMs.