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Brainwavz B400 Review


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Trusted Reviews Recommended


  • Amazing price for a quad-driver
  • Great accessory package
  • Pro-quality build
  • Fab mid-range and treble detail


  • A little too warm sounding

Key Specifications

  • Review Price: £159.50
  • Carry case
  • Removable cables
  • Standard and balanced cables included
  • Quad-balanced armature drivers

What are the Brainwavz B400?

The Brainwavz B400 are quad-driver in-ear headphones. They have four micro drivers per earpiece – which is generous for any kind of earphone, let alone one costing £159.

Shure’s SE846 have four drivers, but cost £829. Ouch.

The number of drivers don’t mean a thing if sound quality is poor. Thankfully, Brainwavz’s B400 sound great – although their excessive warmth fails to highlight their great detail as much as we’d like.

Related: Best true wireless earbuds

Brainwavz B400 earphones with transparent casing on white background.

Brainwavz B400 — Design and comfort

I reviewed the Brainwavz B200 in 2017. They were one of my top picks for in-ear value and sound quality that year, but I wasn’t a fan of their slightly cheap-feeling construction.

Brainwavz has addressed that in the B400, and is now actually making the B200 with the new shell design too. The B400 have 3D-printed earpieces, made of “liquid resin”. This gives them the look and feel of a pro-grade IEM.

Our pair uses translucent resin. The Brainwavz B400 are also available in red, blue, black and black with shimmery sparkles.

Their style is what you’d expect of a pro IEM too. You wear them with the cable running over your ears, the last few inches of the cable moulding to fit. Not everyone will appreciate such a fit, but it does cut down on microphonic “cable rustle” and stops the Brainwavz B400 from working their way out of your ears. I’ve worn them on the treadmill without issue.

I find them fairly comfortable, but bear this over-ear arrangement in mind.

Brainwavz B400 earphones with case and accessories.

Like other Brainwavz products, the B400’s accessory package is just about unbeatable. You get a semi-hard carry case, plenty of silicone tips, a pair of Comply foam tips, an extra cable, and even a couple of “cleansing wipe” packets. These wipes are designed for hearing aids. But I assume the liquid resin used here is similar to that of such earpieces.

The spare cable isn’t exactly the same as the default one. There’s a three-button remote on the cable attached initially, and no remote on the other.

Brainwavz also sells another cable, which terminates in a “balanced” 2.5mm plug rather than a standard 3.5mm one. Your phone won’t have one of these sockets (heck, it might not have a jack at all these days), but some high-end digital audio players use them.

Brainwavz B400 earphones inline remote and cable detail.

Each cable uses MMCX connectors that plug right into the earpiece. Many of you won’t have used one of these before, but MMCX is a conventional socket, making any future replacements a doddle. That said, if you manage to burn through a couple of quality cables such as these then you’re doing something wrong. They’re silver-plated, too.

Brainwavz B400 earphone with transparent housing and black cable.

The Brainwavz B400’s smoky translucent finish doesn’t let you see inside the earpieces as well as the Sure SE846, but we already know what’s in there anyway. Brainwavz uses Knowles drivers – the company behind the drivers in the amazing AKG K3003, Noble earphones and ACS custom in-ear monitors.

Knowles is the real reason these quad-driver earphones are so affordable. Well, that and Brainwavz’s usual super-aggressive pricing.

Brainwavz B400 – Sound quality

Brainwavz says it uses each of the B400’s drivers for a different part of the frequency spectrum. All of them are balanced armature drivers. In recent years, the trend has leaned towards a mix of dynamic and balanced types: balanced for mid/treble clarity and detail, and a dynamic for powerful bass.

However, the Brainwavz B400 don’t display the typical balanced armature sound, which is neutral, clean and clear – but not always that powerful.

They are lush-sounding, significantly smoother and mellower than the B200. The Brainwavz B400 combine refinement with the sort of warmth some associate with an “analogue” sound. They’re as far from cold and analytical as you can get.

Brainwavz B400 quad driver earphones on white background.

Like the B200, the Brainwavz B400’s detail is excellent for the price. Rendering of vocals is intricate. Their texture has more refined contouring, and it lacks the slight shouty hardness that can creep in with Brainwavz’s dual-driver earphones.

Bass representation is similar. There’s plenty for my ears but it isn’t thunderous, so rumbling that it feels as though there are subwoofers in your ears. It’s fast and taut, though.

In some ways, the Brainwavz are categorically better than the B200. They sound like a higher-end pair. I might go as far as to say I prefer the B200.

Some may interpret the B400’s mid and low-mid range warmth as “musical” character. But to my ears it actually undermines the great mid-range detail by filling in too much sonic space. The soundstage is decent, but not epic. You end up with a light clouding of the mids.

The Brainwavz B400 treble is also less pronounced than that of the B200. It adds to the relaxed, soft-edged character.

Brainwavz B400 quad armature earphones on white background.

Why buy the Brainwavz B400?

What are you after? If it’s definition and clarity, I’d actually recommend you consider the B200 over the Brainwavz B400. A little less warmth and sharper treble gives them better perceived clarity, even if they are less detailed.

The Brainwavz B400 have silky-smooth sound allied with an almost analogue character. In some respects –including mid-range detail – they’re close to best-in-class at the price. However, I find their approach a little too soft around the middle.

It’s only frustrating because these would otherwise be – like the B200 – my top recommendation at the price. As-is they’re still up there, especially when Shure alternatives such as the SE215 and SE425 are significantly more expensive.

Related: Best headphones



A top-quality IEM – worth buying if you like a more warm and inviting sound.

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