When considering the brand new Sennheiser CX 400BT in-ear wireless headphones you have to remember one thing, these are Sennheiser. So the $299 price tag might seem steep to some, but in reality, it’s a bargain.

Sennheiser’s other in-ear wireless headphones the Momentum True wireless are $499 – so this is a big step down in price and while they are a different product, they hold true to the Sennheiser sound style.

Ear showing the placement of the Sennheiser CX400BT

Sennheiser Sound

It seems like a “sit back and let the music do the talking” kinda vibe that Sennheiser take to things. As Christian Ern, Portfolio Manager for Consumer Headphones at Sennheiser described to me, they attempt to “emphasise the Bass without being tonal, not to colour the tone of the music.”

And it really is a clean sound from teh Sennheiser CX 400BT.

Two earbuds in the hand

Out of the box pairing is a breeze, and while the “neutral” sound profile they come with is clear and crisp, like me you might prefer a tweak.

Using the Sennheiser Smart Control app you can quickly and easily tweak the EQ to suit. Using a single point and a wave pattern to guide your sound.

Adjusting the EQ in the Sennheiser App

You can save presets if you choose for different listening styles.

Personally, I went up on the curve with a bit of a leaning toward treble, I’ve never been one for a heavy Bass.

How well do the Sennheiser CX 400BT Fit?

In the ear they are a snug fit, and despite their seemingly large size in your fingers, when you put them in your ear and twist to get a snug fit, they are really comfortable.

Earbuds in the ear

They are so light you certainly don’t notice them, and I feel comfortable wearing these for a long period during the day.

In the box you’ll find adapters are provided in a choice of four sizes for the right in-ear fit.

Product Quality

The Sennheiser CX 400BT are not at the level of the Momentum series – that fabric coated case, the high quality material – that’s Sennheiser stuff. These feel a bit cheaper, more plastic case, lighter materials – both to a price and for comfort I think.

product case and charger

But that is certainly not to say these are poor materials or construction in any way, this is a comparison to the upper range of Sennheiser product.

I think to be fair, they fit pretty well into the $299 category, though I’d say in the hand you’d compare them more to a product in the low $200 price point – but they don’t come with Sennheiser sound now do they!

Sennhesier CX 400BT Battery Life

Fortunately, that larger design leads to a great battery life. 7 Hours they say, and I have no reason to doubt that. plus, two full re-charges in the case.

Single Earbud

Headphone controls with a tap

You have a huge range of controls on the touch sensitive outer surface (where the logo is)

Sennheiser App sound controls

And it’s really well paired with call control one side, track control on the other.

Sennheiser App Controls

Voice assistant integration is easy and works from the first use.


These Sennheiser CX 400BT headphones have an impressive sound quality from the 7mm driver, but really come to life best when paired with the app for EQ control.

Trevor Long wearing the Sennheiser CX 400BT

Bass is there if you want it, though I think someone seeking bass should consider Beats or similar – these are for someone looking for a wider range of music appreciation – someone that notices that extra sound in a tune they’ve heard for years on different headphones and speakers.

Sennheiser CX 400BT Australian price

At $299.95 they aren’t cheap – but nor should they be – it’s what’s inside that counts here and you’re buying a sound heritage for sure.