Brainwavz S0

Close-up of the S0

So, a while back, I got an e-mail from Brainwavz, saying they had a special new budget IEM up their sleeve – the Brainwavz S0, priced around ~$50 – if you’d like to buy them, here is the Amazon link, with links to alternative sellers at the bottom of this article.

Having previously reviewed the Brainwavz Delta, which I liked a lot, I frankly got curious enough to take my headphone reviewing “career” out of hiatus (yes, it’s just a hobby and nothing else), I replied to the PR e-mail, asking for a pair for review.

A quick e-mail exchange later, a message arrived, saying “Your Brainwavz S0 has shipped” (which is where my disclaimer belongs: This review sample was provided to me by Brainwavz public relations).

So, let’s get going:

The package

Being a bit more upmarket than the Deltas, these come in less of a budget-oriented package: Display window behind a lid that attaches magnetically to the package.

Package with display window opened

Inside the package

Included in the package is the following:

  • The Brainwavz S0 themselves
  • A shirt clip
  • Carrying case
  • Velcro band for organizing headphone cable
  • A variety of silicone tips plus a bonus pair of Comply foam tips.

The case

The carrying case, opened

In most of the cases where I’ve gotten a carrying case with my headphones, it has ended up staying at home, for one of two reasons. In the case of a headphone like the B&W C5, the included carrying case is tiny, because they want you to pocket the headphones in the case when not using them.

The problem with B&W’s approach is twofold:

  1. The case is still on the big side for comfortably pocketing in skinny jeans
  2. It’s also small enough for me to worry that I do more damage by trying to fit the headphones in the case than storing them without

Then, there is the curious case of the a-Jays Five. In hard-shell plastic, and has storage slots for the earbuds, so it fits precisely. In theory, I like this approach best – it’s what Apple does with the EarPods, and is, theoretically, a neat idea.

In practice it doesn’t work, because the case is about the size of a hockey puck – so it takes up a considerable amount of space in a backpack, and packing and unpacking takes forever.

The Brainwavz carrying case is a sort of happy medium between the two. It’s bigger than the C5 carrying case, which means that I won’t have to worry about the case kinking the cable or crushing the headphone. It’s smaller than the hockey puck, so will fit in my backpack when travelling without displacing other stuff.

The tips

Seven of the eight extra tips

The S0 ships with 8 pairs of extra tips, for a total of nine tips

  • Medium-sized Comply foam tips (I believe the T-400) – not shown in the pictures, as I discovered them only after tearing down my photo studio setup.
  • Five pairs of single-flange tips, in two color codes: Three reds and two greens – note that the Brainwavz site does not list the greens, so I don’t know whether you’ll get those when purchasing. (More about these later, as the red and green sound different)
  • Double-flange tips
  • Triple-flange tips

Getting to the meat of it: The IEMs themselves

Close-up of the metal housing

The construction housing is metal. Brainwavz don’t disclose which metal, but I assume steel. When comparing weights on a scale, they weigh in at around 3g per earbud, tips included, which is three times the weight of the HiFiMAN RE-400, but still a fair bit less than the C5.

The cable is a flat, silicone-type covered cable. For a flat cable, it feels pretty solid, and there is good strain relief in all locations where this matters: On the earphone end, in the y-splitter and on the plug.

The plug, bless Brainwavz, is straight. Some people seem to like 45-degree type plugs, but I’ve never liked them, since they are just as bulky as the straight plugs, and they seem much more prone to applying torque to the connector when plugged or unplugged. I much prefer 90-degree slimline or straight plugs.

Comfort and ergonomics

… and herein lies my niggles with the S0. Ergonomically, there are two problems.

First out is the cable. While flat cables are excellent for avoiding tangling, they’re also an excellent means to cause microphonics – the S0 cable is microphonic enough to make wearing the headphone cable-down on the front is impossible, except when stationary.

This is all well and good, because the shirt clip can solve “worn in front, cable-down”. Which is a terrific idea if you live in Florida, Southern California or the Canary Islands, where you can wear shirts all year-round. Unfortunately for me, I live in a country that looks like this for a few months of the year. In other words: From October until April, I wear jackets when going out, and wearing a shirt clip is not possible.

You can solve this two ways: Run the cable behind the neck, cable-down, or run the cable over the ear. Both are acceptable compromises, but the flat cable makes over the ear feel, and look slightly awkward at first.

If Brainwavz releases an S0r2, I would’ve wanted a different cable, and I personally would gladly have preferred some tangle-proneness over microphonics.

So, I said two niggles? The second one is also related to the flat cable. With the standard silicone tips, the S0 inserts pretty deeply in to the ear canal. Due to the flat cable being vertically oriented, the strain relief comes quite close to the tip of the earphone, and close enough for the strain relief to catch on my earlobe. For prolonged periods of wear, this caused a bit of chafing for me when wearing cable-down, since the flat cable is causes minute movement of the earphone.

Note that I am a big fan of the Comply TSX series of foam tips (not included), and have done my listening almost exclusively with them. These do away with the problem completely by providing the fraction of a millimeter’s clearance between the strain relief and my earlobe.

The sound of ear tips

Before I start writing about the sound, I’ll have to rewind a bit to the included accessories. I mentioned that the silicone tips that ships come in two colors: Red and green. The green tips have a narrow nozzle opening, and provide more bass emphasis than the red tips, where the nozzle is strictly sylindrical.

My impressions are made from listening strictly with the pre-fitted red tips, or with the Comply TSX-400 tips. The bass-heaviness of the green tips is way out of my comfort zone, as I don’t like bass heavy headphones, and the bi and tri-flange tips have never sat well with my ear canals.

I did not use the included S-400 tips as the fit was slightly too small for my ears, but from experience, there is no discernible audible difference between the TSX and S series.

Also, in my testing, the difference between foam tips is very minor, if even existent – there were time where I thought I heard differences, only to not hear that difference when I went back to verify.

The sound of music

Note that I haven’t subjectively assessed tonality with test tones. I haven’t measured them. I have listened to them over a large set of songs in many genres, for extended daily periods over a period of a few weeks. Mostly songs, albums and artists I know extremely well, but also tracks that are entirely new to me. Listening has mostly been through an iPhone 5S, mostly playing Apple Lossless – either from the built-in music player or through WiMP HiFi (In the UK and US, this service is known as TIDAL). I have also done listening in my desktop setup with the ODAC and O2 – both of these sound similar enough to

Sound-wise, I have long held the HifiMAN RE-400 as the champion of sub-$100 IEM’s, offering a glimpse of what high-end audio is about: Tonally neutral, without any veil, and plenty of detail. That is also roughly my order of priorities, with the derivative feeling of “sound stage” as the next on the list. It should be noted that I’m placing “sound stage” in mock quotes here, because it doesn’t actually exist with headphones. No matter how hard you try, sound still stays in a line between the left and right ear, instead of what you experience with a good 2-channel stereo setup, that places sounds not only along a width, but also front-to back.

When I tested the Brainwavz Delta earlier this year, they vere tonally neutral enough, but in the detail department, they suffered next to the RE-400, with the HiFiMAN’s having much more detail, and feeling more open. In that comparison, the bass, while having tonally the same character felt a tad less dynamic, or if I’m to put it into words, “slow”

Back then, I also acquired a pair of JVC HA-FX40. They were fairly evenly matched with the Deltas: Better in the treble and detail department, but did so at the expense of the mid-range, using a v-shaped frequency response. Choosing between those two are merely a matter of which compromise you want to make in the $15-20 headphones.

That previous experience also set my expectations for this headphone. Based on my previous experience with the Delta, I had expected to spend my listening time comparing the S0 to the Deltas, and to the JVC (Despite the latter’s departure from strict neutrality), and I had imagined that they would be a slightly improved S0.

I simply couldn’t have been more wrong, and after my initial three minutes of listening, I decided that a comparison against the Delta or HA-FX40 was meaningless, because, if you are making a comparative review, if I am to use a martial arts metaphor, it would be a knockout on the first punch.

The one word that best describes my reaction when I put them on is: gobsmacked.

I had intended – as I usually do after having taken pictures of headphones – to listen for a song or two, before I take them off and go process the images.

That was not to happen. Coming back from a travel, I had come immediately off exclusively listening to the RE-400 for a full week. In fact, I had only removed the RE-400’s a few minutes prior to putting on the S0.

My initial reaction: gobsmacked

The same subjective neutrality as the RE-400, but very, very unlike the Delta, no perceived lack of detail, and no obvious rough edges. I played through all of “Wish You Were Here”. I moved over to Mike Oldfield’s Tubular Beats – a set of dance/techno mixes of various songs from the Tubular Bells trilogy. That too was listened to straight through. Trentemøller – Into the Great Wide Yonder.

By this time, I had stopped trying to listen analytically – I was just gobbling through records one by one, and forgetting that I was to actually write a review of these. The one impression that I was left with when I went off to bed was “agreeable” – no obvious deficiencies in the sound, and an overall euphonic presentation.

In short: They were competing head-to-head with the twice as expensive RE-400, instead of being a minor improvement on the absolute budget end of the spectrum.

Over the next weeks, I used the S0 in a variety of settings, ranging from in the comfort of home, to a shared office, or on public transport, and during this period, I was also able to form a more solid opinion than simply “good”, and I’ll make some notes here:


Let it be known that I’m not a particular fan of the Olive-Welti target curve for headphones – I find that most of the headphones that follow it fall down on the bass heavy side of things, which is why I’ve loved my RE-400’s so dearly. That said, the RE-400 can sometimes lack a bit of low-end impact, which is why I sometimes deliberately choose a non-neutral IEM if I’m in the mood for something a bit meatier – I’ve typically used the a-Jays Five, which is everything but neutral, or the JVC’s mentioned further up in this review.

The S0’s are no Olive-Welti cans – they are subjectively bass neutral, and compared to the RE-400, they actually improve on them. Subjectively put, it seems both more solid and better extended, and are actually more reminiscent of the HE-500 than the RE-400. Taking a test tone to them solidifies this impression – subjectively, the HiFiMAN IEM’s start fading gently at 50Hz, and are noticeably down by 30Hz. The Brainwavz’ are subjectively flat down to 30Hz, where they start falling off (listening at the same perceived volume in both cases).

In addition to that, if you listen/test at high volumes, the S0’s also feel cleaner in the bottom end. Take a pure sine wave to them, turn up the volume, and the S0’s sound cleaner – in relatively short bursts of high SPL sine waves, there are less perceived harmonics – it simply sounds cleaner.

What does this mean in practice? For many recordings of actual music, the differences are fairly subtle, but where the music has a rich bottom octave, the S0 feel a bit more meaty, and if you frequently listen to dubstep and electronica, the S0’s are a clear winner in the bottom end.


I’m going to have to call a draw between the RE-400 and S0 here: They are equally well-defined, and both are as buttery smooth as you can expect from anything in this price range – nothing is recessed, and nothing sticks out. There is none of the attenuated upper bass and midrange you often find on bass-emphasized or v-shaped cans, nor is the midrange exaggerated like some speaker audiophile reviewers seemed to enjoy in the late 1980’s and early 1990’s. Time for an aside here: In the the mid-90’s, I was among a loosely organized group of audiophiles who would visit each other, and relative strangers to tweak, listen, and opine about each other’s systems. One one of these occasions, I was exposed to a combination of Rotel and Mission speakers, with a Marantz CD player. The combination of mid-range distortion, and focus on the middle and upper end of the midrange, and low end of the treble that listening was physically painful at anything but the lowest levels.

The S0 is none of that. As I said, put side by side with the RE-400, they are an even match, both for detail and evennness of response, and both are on par in this area with the Sennheiser HD 558, slightly losing out to the HE-500 (with Focus pads).


Bass is what sells headphones. Treble is what kills them – there are headphones that I find downright unlistenable due to their treble response – I for one can’t even listen to any Grado any more, due to their massive 2000 Hz peak, and when I wanted to try out the Monoprice 9927, I couldn’t even listen to them long enough to write a sensible review.

Nor can I listen to a headphone that doesn’t have treble – it kills clarity, fine detail and life from the music. Miss this area, everything is just that little bit lacking

In the treble area, the S0 is doing some tightrope walking. Put side by side with the RE-400 or HE-500, there is some emphasis (subjectively, I’d say between 1-2 dB), being slightly less emphasized than the Sennheiser HD 558.

In practice, this isn’t going to be a problem – with normal recordings, they never tip over to being overly sibilant. There’s no s or z sounds ready to shred your eardrums, and you’re not going to notice it much in most conditions.

The one recording where this difference is obvious is Kari Bremnes – Byssan Lull. That link goes to a Youtube upload – while not lossless or even transparently encoded, it still replicates the frequency range in question in a close enough fashion to use as an example. The recording may be available on WiMP, TIDAL, Spotify or in the iTunes store, if you want a better-quality copy.

This recording in many respects goes back to what I mentioned earlier about what was favored by some speaker audiophiles during the 90’s – the entire album has both the midrange and treble recorded a little on the hot side, and if you crank it, it can sound pretty harsh, even on truly neutral systems.

The S0 sound a bit harsher on this recording than the RE-400 or HE-500, but less so than the HD 558, and less so than many high-end speaker systems, but if I was to shift my music taste to exclusively listen to Kari Bremnes, I might choose a different headphone. I’m not at all sure which of these two is the more correct representation of this track, though.

Air and soundstage

I said it above, but I’ll repeat it: Headphones do not have what I consider sound stage or imaging capabilities when served recordings that aren’t binaural (outside of using various DSP solutions that emulate it), so I’m merely referring to it as a sense of:

  1. Spaciousness
  2. Perceived width of the between-the-ear image of the sound

In that respect – the S0 is good. There is a good sense of spatial separation between instruments along the left-right axis, and the stage is reasonably wide for an IEM. It’s on par with, or even a tad above the S0, but still not reaching quite up to neutral and open over-ears. If I’m to attribute it to anything, it’s that treble remains relatively perceived flat up to 15-16 kHz, and it offers a tad less isolation than the RE-400.


Yeah, I write too much, so let’s just do a TL;DR in the form of pros and cons


  • Neutrality
  • Bottom end-solidity
  • Clarity
  • Build quality
  • Packaging and accessories


  • Microphonics
  • Flat cable
  • May be chafe-prone when worn cable-down

The slightly more interesting thing is if I would recommend them? That answer is a resounding yes. These have, in the few weeks I’ve listend become my “daily driver”. In the past, I’ve usually brought the RE-400 with me, or mixed it up with the a-Jays Five or HA-FX40, if I’m in the mood for something “fun”. By virtue of their better extended bass, they sound more solid with electronic music, while remaining supremely usable with acoustic or electric music. The build quality is also seemingly very, very solid, and I never fear they’re going to fall apart on me.

If I wanted to change the headphones, I would do very little to the sound signature. I am however hoping that Brainwavz release a version with earhooks/loops, or with a round cable (from the splitter up), as that would likely solve the chafing issue I noticed with silicone tips.


If you want to buy these, they are available from MP4Nation for $49.50 with free two-day shipping to may destinations. If you prefer ordering through Amazon, here is that link.

The Delicious Brainwavz Delta

Money shot

My relationship with IEMs is somewhat troubling. While I’ve been using them for over a decade, I’ve never been able to find a budget-minded mdoel that I’ve liked, and have gravitated towards IEMs from about $100 and up, thinking that’s where the best price/performance ratio is to be found.

However, as a moderator of /r/headphones, I’ve seen a lot of people who aren’t willing to carry $100 worth of IEMs with them, since they inevitably destroy or lose them. Thus, enter the budget IEM. (I’ll define anything below $30 as “budget” here).

While I’ve given the Apple EarPods a positive review in the past, they aren’t technically IEMs: While they sit in the ear canal, they are an open design with virtually no isolation, giving it some very real limitations in sub-bass response, and they aren’t the best option in situations like airplanes or the library, where you want to shut out noise, or not bother everyone else with the sick beats you’re listening to.

So, I started looking at budget IEMs. Ranging from a pair I bought on eBay for $1.52 to pairs in the $20-30 range.

First out is the Brainwavz Delta. Amazon operates with a “list price” of $39.99, but the median street price seems to hover right around $20. So, let’s have a look at them to see how they work out.


The packaging is pretty much you’d expect from a $20 headphone – cardboard box with plastic window, with the headphone and supplied accessories inside. One big plus: Brainwavz have opted for frustration-free packaging – there’s no welded plastic requiring tools for opening – simply remove a seal, and open the lid. While I think Apple’s packaging of the EarPods is slightly better – as it doubles as a carrying case, it’s hard to fault Brainwavz here: The packaging includes everything you need, and they have instead spent the money on the contents of the package.

What’s in the package?

The contents of the package is as no-frills as the box it came in – here’s what’s included:

  • User manual
  • The Deltas themselves
  • Four pairs of tips: Small, medium and large silicone tips, plus a pair of Comply S-series foam tips.

Had there been any more in the box, I would’ve accused them of spending money where it doesn’t matter. The selection of tips cover most cases, and anyone should be able to find a good seal with the included tips.

While the Comply tips in the package doesn’t suit me or my preferences, many like them, and get both a better seal and more comfort, so a huge plus for including them.


This is where things start getting good. If you inspected these headphones, without knowing anything about them, you’d never think they were $20.

Image: TRS connector

The TRS conenctor is a 45-degree angle. I’m not super fond of this form factor, and either prefer a proper 90-degree connector or a straight one – this one adds the bulk of the straight connector, and is no easier to use than the 90-degree angled connectors does. That said, the connector itself is good quality, and it has properly good strain relief – even better than I’ve found on many more expensive IEMs.

Image: splitter

Much the same goes for the y-splitter: It’s solidly made, has good strain relief, and has a good-quality adjustable slider.

And now, on to the earpiece itself.

Image: housing

This is where I say “Wow”. The housing is all metal, feels very solidly made, and looks good. . I’ll just repeat myself from a few paragraphs back: You’d seriously never think these were $20 headphones by looking at them.

Image L/R print

Markings for left and right are printed and visible on the earpiece itself, rather than on the cable. It’s perfectly adequate, but if I have a wish, it’s one that applies to all headphone manufacturers – I want left-right markings that is tactile, so I know which one to put in without having to turn on a flashlight or find some light somewhere.

If I put on my “overly critical” glasses, I would like a thinner strain relief, like that found on the HiFiMAN RE-400. That said, it isn’t a huge problem – unlike the RE-400, these aren’t deep-insretion IEMs, and the strain relief doens’t get in the way.

Inside the housing, behind a thin (metal) mesh, you’ll find an 8mm dynamic driver with a rated impedance of 16Ω.

Comfort and use

Overall, the Deltas are very comfortable. While they weigh more than the RE-400 or the a-jays five, with a slightly larger housing, you never notice that they’re there.

Also, as I hinted at above: 95% of all buyers should be able to fit these and get a seal with one of the four pairs of included tips. And when you get a fit, a huge positive surprise is in microphonics.

Over the years, I’ve tried headphones that are virtually useless because of excessive microphonics, forcing you to wear them in one particular way, and I even own a pair that tries to deal with the problem using a loop of memory wire pinned to your pinnae. With the Deltas, no such thing: I can wear them hanging down in front or behind my neck, and I can wear them looped over my ear – microphonics is never an issue. (As an aside: The Deltas sound better than the B&W C5 – a headphone purchase I now consider to be a huge mistake)

Isolation and leakage is also perfectly adequate – subjectively, they seem to be on par with the HiFiMan RE-400, trailing slightly behind the a-jays five and B&W C5. Making comparisons to stuff more in its own weight class/price range: They are far ahead of a budget IEM like the Monoprice 8320. If you crave more isolation, the solution is Comply foam tips, but unfortunately for me, the included pair were too small to provide a seal


While I don’t believe in burn-in, the headphones have been playing straight for days without any critical listening, and testing is done on a variety of gear in various combinations:

  • iPhone 5S, iPad 3
  • O2 headphone amplifier
  • Focusrite Scarlett 8i6

On Brainwavz’ product page, they make the following claims about the sound:

clear instruments & vocals
balanced bass

and they go on to write:

The Brainwavz Delta produce vocals and instruments with detailed clarity, letting your music sound as good as their artists intended.

Which I, when I first read the blurb chose as “largely neutral”, perhaps edging towards “detailed”. So, do the Deltas live up to Brainwavz claims, and my expectations?

The short answer to this question is “yes”.

The bass itself, while not as tight and controlled as with the HiFiMAN RE-400 is still leaps and bounds ahead of what I was expecting from a $20 IEM: It perfectly matches what I expect from a headphone that markets itself as neutral. Subjective extension is good – down to 30 Hz, or so whereafter it gently starts rolling off.

While I could’ve wished for a tad more punch, speed and authority in the bass, I absolutely can’t fault them – it’s only when I compare to my other references I’m noticing, and I’m primarily a full-size planar guy, so my expectations here are way too high.

Moving on to the midrange. In the past, many people have championed the Monoprice 8320/9927 as the IEM to go on when on an extreme budget. Prior to writing this review, I picked up a pair, so that I would have a comparison that was actually fightning in the same weight class as the Deltas. I hated every minute of the hour or so I spent with them before I threw them in a box in disgust. The midrange was erratic, uneven, harsh, and they were hugely sibilant. Any music with vocals with a language that happened to use ‘s’, ‘z’ and ‘ch’ sounds felt like being repeatedly stabbed in the ear.

Prior to receiving the Deltas, but after being exposed to the 9927s, I feared I was being set up for a harsh-sounding midrange. Said fears were soon alleviated: Much like with the bass, there are no obvious problem areas that make the headphone sound offensive or unpleasant – it gobbles up most recordings – without making them harsh, hard or tiring to listen to. If I am to fault them for anything, it is that the upper midrange can feel a little bit recessed when compared to my full-size cans, a-Jays or RE-400 – it’s not a massive problem, though.

As for the treble: For a $20 can, it’s good. Put side by side with other cheap offerings, I can’t fault it at all. The top of the midrange and treble is really also the area where differences against my full-sized cans and daily driver IEMs shows. There’s a fairly distinct lack of detail and air, when put side by side with any of the cans I use on a daily basis.

That said, it’s really only in detail retrieval where it becomes evident that you aren’t dealing with IEMs in the $70-100 range. While I mentioned it in the context of the upper midrange and treble, it is evident in the lower frequency ranges as well, but far less pronounced – it’s generally just perceived as a softness in transients.

That said, The Deltas are a fair bit ahead of anything I’ve tried in a similar price bracket. Put them side-by side with a full-sized budget favorite like the unmodified Tascam TH-02, and it’s less piercing than the Tascams with their treble peak, and when side-by-side with the Monoprice 8320/9927, there’s no contest – the Brainwavz are actually pleasing to listen to.

Conclusion / TL;DR?

If you’ve gotten this far. I think the conclusion is a given. In the process of reviewing these, I’ve had to try a number of other headphones in the same price range, some of which are best forgotten about. I’ve tried a competitor with so poor quality control that if/when I write a review of it, I shall have to write to separate reviews – one for the left ear, and one for the right. I’ve tested headphones that feel like they’re falling apart on me, or that felt fallen apart when they arrived in the mail.

The Brainwavz Delta is none of that. In many respects, the build quality rivals or exceeds that of more expensive headphones, and the sound quality is much better than I had expected from a $20 headphone. They’re going on my very short list of sub-$30 recommendations, and if you’re looking for a beater or budget IEM, these are, in my very humble opinion the ones to get.