Build Quality, Packaging And What Have You
The packaging is typical Brainwavs fair – a black box with a window that displays the IEM. As far as accessories go, there’s the three pairs of single flange eartips in small, medium and large and a pair of Comply S400 foam tips in black, which are my personal favorite.

I’m not a fan of Comply as a company, but that’s more due to practices and not product. The foam tips are excellent and I’d bet a majority of the people who actually experiment with changing the tips will find them to be to their liking. There is also a shirt clip and a hard case which is the perfect size if you wrap your earbuds up correctly.

As far as quality of the build is concerned, it’s definitely in-line with the $70 price tag. The housing is aluminum all the way through and it definitely feels sturdy to use. There’s a vent at the back of the housing that’s very noticeable, but I personally think it works well with the styling.  The only issue that I’ve come up with is the cable.

In that, there’s a ton of noise from it. If you don’t know what that means, put earbuds in and rattle the cable around. If you hear a deafening sound, that’s the noise I’m talking about. While the braided cable covered in rubber looks awesome and feels sturdy, don’t expect to leave these in passively without music playing or anything like that while you’re moving.

Comfort
I’m generally a big fan of all Brainwavz products in regards to comfort. Their full-size offerings are very comfortable and the Betas sit perfectly in my ear canal.

Happy to report that the M4 is more of the same. The small tips fit just fine with solid isolation, and the comply tips also fit very well. Don’t shove the whole thing in there, but insert them naturally at an angle and sit the tips inside the ear canal. I haven’t had any problem with looseness or anything of that nature.

Sound Quality
The M4 do a great job of sounding like everything Brainwavs has come out with thus far, but much better (with the exception of the top of the line B2). As noted, there’s a full bass sound with these earbuds that many will enjoy, but it’s not exaggerated and is actually set a ways back. The lows all-around have a strong presence without being overbearing. Hip-hop will sound appropriately strong.

When it comes to the treble and the highs in general, they can be a little too bright and over-produced. I get a definite harshness on some of the more intricate cymbal work, but it doesn’t seem prominent and consistent throughout my testing.

That being said, I also notice it a lot on the more shrill snare hits. One prominent example is “Stan” by Eminem – the snare hit is actually somewhat unbearable in that song – but that’s also something experienced to a lesser degree with other headphones. The highs perform admirably on other genres with a very neutral sound in that regard. Folk and indie music in general sounded very front-and-cetnter – the brightness lessened due to the lack of punch which generally dominated hip-hop.

What these IEMs are doing is masquerading as having a neutral signature while still appealing to the bass crowd. It’s not a neutral signature – it’s actually somewhat v-shaped, but it has a very wide soundstage for an IEM, especially in this price bracket.

In short, the sound is very wide and out there – the M4 were probably built to satisfy many hip-hop fans and instead they’ve managed to make a great all-around IEM that doesn’t offend them outright. I can’t recommend the sound enough at the $70 price point and you’d be hard-pressed to find something better at it.

Sounds Great: Hip-hop, folk, anything that is “active”
Sounds Bad: Extensively cymbal-driven music like freeform jazz and obnoxiously slow tracks

Notable Tracks Used In Review: Kendrick Lamar – “HiiiPOWER”, Eminem – “Stan”, Aloe Blacc – “I Need A Dollar”, mc chris – “mc chris is dead”, Larry and His Flask – “Ebb and Flow”, Feist – “Graveyard”, White Rabbits – “Hold It To The Fire”, Thrice – “Promises”, Regina Spektor – “All The Rowboats”

Verdict
I love the purchase when I got ‘em on sale for $28, but they’re back up to $60-plus at the moment. That being said, I consider them well-worth it and rank them among my favorite in-ear monitors, being surpassed only by buds in the $150-plus range.

They’re less-fun than the Ultimate Ears TripleFi but have more bass than the Brainwavz B2 – their flagship. I found myself outwardly bored when listening to slow jazz but was very happy with their presentation of folk and hip-hop music.

Will they rock your skull? No, and they probably won’t blow your mind, either. That being said, if someone took mine away from me today and said I had to buy a new pair at $60, I’d first try and bludgeon them with knees and elbows to get mine back. Failing that, I’d buy ‘em at retail again in a heartbeat.