Big sound, small price.
The first thing that people notice about the Brainwavz M4 is that it has a very low price tag. As of this writing, they can be had for as low as $40. I was not expecting a whole lot from an IEM with such a low price, but Brainwavz taught me that good things can be had for very little.
The build of the M4 is phenomenal. The housing is made out of aluminum, and feels just as solid as any other aluminum IEM. The 3.5mm plug is very durable, and has a luxurious, hard rubber feel to it. The cable is the same tangle-free cable that is featured on the Brainwavz M2. It's difficult to get the M4's cable knotted-up, but the cable always looks as if it's curled. It acts the same was a pipe cleaner does, and I'm not a fan of that. Even though the cable is a little bit of a nuisance, it made up for it by rarely tangling. The M4 also comes with a small carrying bag. The zipper on the carrying bag is of extremely low quality, as it broke on the first day that I had it. The loss of the bag was not tragic though, because the M4 is durable enough to be crammed into a backpack/laptop bag pocket.
The M4's design was impressive. It's very sleek and minimalistic. The metallic “BRAINWAVZ” print on the outside of the housing looks very professional, and gives the illusion that the M4 is a much more expensive IEM. Again, the cable is keeping the M4 from really blowing me away. Since it behaves like a pipe cleaner, the cable gets twisted up and looks a little silly in public. It's not a deal-breaker, but it's definitely something that got on my nerves.
The M4 is very much like the M2, but with punchier bass. While it's not fantastic or breathtaking, it sounds good enough for me to make it my main budget IEM. The soundstage was surprisingly open, and the isolation was fantastic.
The highs are slightly lacking in the M4. They're definitely present, but they don't have the sharp definition that I'm used to. Crash cymbals in music just didn't have the sparkle that I love.
The mids are the best part of the M4's sound signature. Male voices were clear and detailed, and guitars sounded surprisingly crisp. Unfortunately, the mids seemed fairly recessed in comparison to the highs and lows.
The bass and lows in the M4 were booming. The aggressive and hard-hitting bass sounds great in electronic and hip-hop, but is way too overpowering for genres like classical.
The M4 is a little too bass-heavy for my taste, but I know a lot of bass heads who love the aggressive lows that are featured in the M4. It's very fun to listen to, and I would definitely recommend it to a friend.