Sennheiser CX Plus review: Great sound, lacklustre ANC

Following hot on the heels of the Momentum True Wireless 2, CX 400BT and CX, the CX Plus are Sennheiser’s fourth pair of earbuds in two years. These affordable £129 earbuds are another fine example of just how rapidly the cost of true wireless ANC technology has tumbled into the mainstream.

The price is appealing, but it’s disappointing to find that the Sennheiser CX Plus’ ANC performance is lacklustre when compared against similarly priced rivals. Overall, they’re saved by good, neutral sound quality, an extensive range of customisation options and a more comfortable fit than many other buds on the market, but sadly they fall short of a class-leading performance.

Sennheiser CX Plus review: What do you get for the money?

The CX Plus are a well-specified pair of earbuds boasting Bluetooth 5.2 connectivity and support for the SBC, AAC, aptX and aptX Adaptive codecs. Few buds in their price bracket can match that kind of codec support, but don’t forget, your audio source also needs to support aptX and aptX Adaptive if you plan on making use of them.

The buds themselves are of the drum-shaped variety and forgo stems, which is either a pro or a con depending on your preference. Their IPX4 rating for water resistance is perfectly respectable for gym and outdoors use, while the five pairs of silicone eartips included should ensure you achieve a secure fit.

Also included in the box is a USB-C cable for charging the accompanying case; wireless charging via a Qi pad is not supported. The case is an all-plastic affair that’s as blocky as the buds but relatively lightweight at 35g. It provides two full charges of the earbuds, which offer up to eight hours of audio playback, meaning you’re looking at roughly 24 hours total battery life.

Playback and call commands can be executed via the generously sized touch-sensitive surfaces on the outside of the earbuds, and controls can be customised via Sennheiser’s Smart Control app.

The app reveals the remainder of the CX Plus’ core features, the most impactful of which are a Transparent Hearing mode and “Smart pause”. The former boosts awareness of your surroundings during those times you’re not using active noise cancellation, while the latter pauses audio when one or both buds are removed from your ears.

EQ options come in the form of four presets (Neutral, Podcast, Movie and Bass Boost), along with a three-band graphic equaliser and frequency curve via which you can create your own presets. The latter can be shaped using your finger and looks cool, but it’s far easier to tweak your audio using the three-band EQ.

The last few in-app options are relatively niche but useful nonetheless. There’s a slider for adjusting how loud your voice sounds in your ears when on calls, an auto power-off feature, an option to automatically answer phone calls by taking an earbud out of the case and the ability to select a specific Bluetooth codec.

READ NEXT: Our pick of the top wireless earbuds under £70

Sennheiser CX Plus review: What do we like about them?

In terms of the positives, comfort and surety of fit sit near the top of the CX Plus’ list of strengths. Pop them in your ears, give them a small twist if necessary and they’ll stay put. They require very little, if any, readjustment once in your ears, and they’re comfortable to wear for extended periods of time.

I was also a big fan of the CX Plus’ touch controls. In fact, they’re pretty much perfect. Actions can be assigned to single, double and triple taps, along with long holds, leaving you with up to eight commands at your fingertips.

This enabled me to incorporate Transparent Hearing, ANC, my voice assistant, play/pause, track skipping (both forward and back) and volume controls, meaning I seldom had to dig into my pocket for my phone. Better still, the touch controls are highly responsive and tone prompts indicate whenever a touch surface is tapped, helping ensure you tap the correct number of times for your chosen command.

Little touches like that, in addition to the ability to adjust sidetone when on phone calls and choose whether your music pauses when you engage the transparent hearing mode, provide a welcome level of personalisation.

That personalisation extends to EQ options, though I found the default sound profile nicely balanced as it was. There’s a natural quality to the sound – no part of the frequency spectrum is obviously boosted, which is in line with the approach Sennheiser takes with its more expensive reference-grade over-ear headphones.

Bass reproduction is impressive, with low-end frequencies attacking and decaying rapidly to deliver a clean, satisfying punch. The Bass Boost preset is one of the subtler ones I’ve heard, adding a bit of extra weight without becoming overblown.

No Doubt’s “Don’t Speak” highlighted the CX Plus’ ability to authentically convey a singer’s unique vocal characteristics. Gwen Stefani’s instantly recognisable voice was clearly articulated in all of its punky, energetic and nasal glory, and her dynamic fluctuations were handled smoothly.

It also served to highlight that higher frequencies are dialled back a touch in the mix. This doesn’t affect the level of detail in the upper registers too significantly but prevents the CX Plus from straying into fatiguing territory, which is welcome if you listen to a lot of treble-heavy music.

Overall, the CX Plus hit most of the right notes musically and the EQ options available ensure you can tailor the sound to your liking. The three-band equaliser is a little more restrictive than those offered by other companies, but does its job well enough.

The Transparent Hearing mode is excellent: I found it to be more effective than similar modes offered by most of the CX Plus’ competitors. I was able to hear the TV in the lounge while sitting in my office and even managed to hold an intelligible conversation with my girlfriend while listening to music at around 50% volume.

READ NEXT: Our favourite Bluetooth headphones

Sennheiser CX Plus review: What could be improved?

The active noise cancellation is far less impressive. I always temper my expectations when it comes to the noise-cancelling capabilities of affordable earbuds, but even then, I felt a little let down by the CX Plus. They do dampen the lowest frequencies to an extent but failed to block out most of the ambient sound during my commutes across London.

There’s next-to-no reduction in the impact of lower mid-range frequencies and voices and other higher-pitched sounds come through very clearly. That’s not particularly surprising given what you’re paying for the CX Plus but similarly priced options like the JBL Live Pro+, Beats Studio Buds and OnePlus Buds Pro all offer more effective attenuation.

The design of the CX Plus will also prove a sticking point for some. This isn’t anything new for Sennheiser earbuds – all of their releases to date have been rather chunky – but if you’re looking for dainty, discreet buds, these aren’t for you. They actually matched the contours of my ears rather nicely but I still had sizeable chunks of plastic protruding from my ears, which won’t go down well with more image-conscious consumers.

My final criticism relates to call quality. It’s reasonable if you’re indoors, but step outside on a windy day and the person on the other end of the line is likely to struggle to hear what you’re saying amid all the background noise. Few earbuds around the £100 to £150 mark are able to isolate your voice completely, but it’s definitely an area the CX Plus could improve on.

Sennheiser CX Plus review: Should you buy them?

The Sennheiser CX Plus are a clear improvement on the two pairs of CX earbuds that came before them. They operate over a newer version of Bluetooth, offer superior codec support and add active noise cancelling and a transparency mode to what was already an appealing package.

If you can’t afford the premium Momentum True Wireless 2 and have your heart set on a pair of Sennheiser earbuds, it’s definitely worth paying the extra £30 for the Plus model, despite their disappointing active noise cancellation.

If, however, you’re not set on Sennheiser, we’d steer you towards the Beats Studio Buds, OnePlus Buds Pro and JBL Live Pro+. Those options lack Sennheiser’s more neutral approach to audio reproduction but all do a better job of shutting out the world around you.