Pairing and Customization

Pairing the Sennheiser CX TWS set is very easy since each earphone immediately enters pairing mode when taken out of the case. The protocol is to initiate pairing with a previously paired device, and there is no multi-point support, making it a 1:1 device. It paired easily with both my phone and laptop, and voice prompts at various stages confirm the status of the earphones in pairing mode and when paired. Sennheiser does not mention the exact Bluetooth chipset, but the adoption of aptX and cVc for the microphones points towards a Qualcomm QCC30xx series chip, especially with the latest Bluetooth 5.2 connectivity but no hybrid ANC or aptX Adaptive. As it stands, there is SBC, AAC, and aptX for codec support, which makes me want to see aptX Adaptive, and LDAC and LHDC. My relatively old phone had aptX, as do my Windows 10 PC and laptop.


The CX TWS earphones are supported by Sennheiser Smart Control, a dedicated app available on the Google Play Store and Apple app store. Reviews for the app are middling at best, with complaints ranging from connectivity issues, battery drain, and poorly implemented features. I did not face any connectivity issues and made sure to only provide location access to the app when it is open, which prevented unwanted battery drain of the phone. As for the features, well, let's get it up and running first. Installation is simple enough, and it is best to already have the earphones paired to your phone or mobile device before proceeding. The app then takes a few seconds to find them before giving you the option to go through the various touch controls as a quick tutorial. That said, some of those steps need to be taken before the app can even find the earphones, so it seems redundant to say the least.


Before we could even use the app, I was alerted to a new firmware update for the earphones. I always recommend updating firmware, but conduct a quick online search to confirm that the new update won't break something else. The process is very different from the usual because it had me set up the update and then put the earphones back into the case, which also had to be closed. It took a very long time compared to any other such firmware update, which is all the more annoying because the app has to be in the foreground the entire time—you can't use your phone without a pop-up message stating that the firmware update will be interrupted if you do anything else. It took all of 28 minutes, which is shorter than the rated 41 minutes, but still a poor showing from a major brand like Sennheiser.


With the app and earphones both finally good to go, we are greeted by a simple home page with a render of the product and a battery indicator below for the earphones. I would have liked separate battery levels of the two channels, and the case if possible. There is also no volume or channel balance slider, which are other features I would have liked to see. Tapping the render takes you to the various touch controls, including media playback, volume control, bringing up the smart assistant, and call controls with the first set for customization based on multi-taps and hold procedures. There is also a simple 3-band EQ in a visual map or a -6/0/+6 dB slider for the bass, mids, and treble, as well as some presets, and edit and add to. This feels like the bare minimum for an EQ option. I would have liked a 5 or 7-band EQ slider for those who want more control while keeping the simpler visual EQ the same for more novice users. Go through the device settings tab to adjust other options, including lowering auto power off from the default 15 min to save battery life, choosing whether you want voice prompts or not, and an interesting "sidetone" feedback that aims to replicate transparency mode during calls.