Page 2 - A Closer Look - Hardware and Software
Unlike what we normally see with in-ear true wireless earbuds, the TOZO Open Buds are much larger in size. The larger body is not meant to go in your ear but rather sit on top of your ear, outside your ear's external auditory canal and over the tragus. The Open Buds are black in color with a lighter gray on the exterior. However, TOZO also has pink and white variants if you desire. The earphones have a matte finish on the body of the case and the earphones, but they do not hide handling marks from your fingers or your greasy ears. Each side is heavier than what you might expect, weighing 10g. This is in part due to the larger body, but also the attached ear hooks that help keep the device in place. The body of each earphone measures 31mm in length, 16mm in width, and 11.5mm in thickness. As there are supporting arms attached to the Open Buds, the extra weight is not as noticeable on your ears. Even so, you can easily feel the Open Buds on your ears due to the dimensions. I would avoid lying down on your side while wearing them.
As for the controls, the TOZO Open Buds use a touch interface that responds to a combination of taps and holds. The outer area of the Open Buds is touch sensitive, which is reasonable given this size. By default, a single tap on both sides is used to play or pause music. Double tapping on the left side will change to the previous track, while double tapping the right side will change to the next track. Triple tapping on either side will bring up the native voice assistant on your connected device. Holding your finger on the left or right side will decrease or increase the volume, respectively. When you are receiving a phone call, you can answer it by tapping either side. If you do not want to answer the call, you can reject it by holding your finger down on either side. Finally, while you are in a call, if you want to hang up, you can also hold your finger down on either side. For myself, I found the touch controls to work well, as I did not notice any false touches and it recognized all of my intended actions. I will say changing the volume did take a bit longer for the earphones to notice, but it did execute the actions after the slight delay.
Internally, the TOZO Open Buds use Bluetooth 5.3 to connect to devices. This later version of Bluetooth is a minor change over 5.2, which brought low energy audio to help with increased battery life. Supported codecs of the TOZO Open Buds include SBC and AAC. SBC, or Subband Coding, is the default Bluetooth audio codec with decent audio quality and low processing power requirements. This codec maxes out at 328 kbps. AAC, or Advanced Audio Coding, is preferred by Apple's devices and maxes out at 250 kbps. Despite having a lower maximum bitrate, AAC is still known to offer better sound quality. Unfortunately, we do not have support for Qualcomm's aptX or Sony's LDAC codecs here for lower latency or higher bitrates.
Taking a closer look at the earphones, you can see the TOZO Open Buds are pretty large for a body, reminding me of the older, single-sided, Bluetooth headsets people used to wear for calls. This is totally unrelated, but I actually know a guy who still wears those single-sided Bluetooth headsets everywhere in 2024, never taking it off, even though I have never actually seen him in a call. Back to the Open Buds, we can see it includes the large hook that rotates in two directions to get a good fit on your ears. It is a bit tricky to explain with words, but with this movement, it does make fitting the Open Buds to your ears pretty easy. As someone who wears glasses, I was concerned the hooks would get in the way of my glasses, but this was not the case. Otherwise, there are no user-swappable parts here, such as ear tips or extra hooks.
Internally, each side has a 14.2mm dynamic driver, which may sound large, but is expected given the larger physical dimensions of each earphone. They have a frequency response range of 20Hz to 20kHz, which matches the typical hearing range of a human. The whole set of earphones have an ingress protection rating of IPX6, which translates to "protection from water from a high-pressure stream from any angle". These should be safe from sweat or rain, making them great for use on-the-go regardless of the weather conditions. I would not recommend swimming with these however, as they are not protected against immersion in water.
Each side also has a pair of pogo pins to charge the set. They also have markings of L and R to indicate which side is for which ear. You can see how there are openings on the inner side to project audio into your ears. The flip side has some microphones on the outside. According to TOZO, there is a dual set of mics on each side to help with noise reduction during calls. Under the outer grille, we also have some LED lights to indicate pairing and power information. Unfortunately, we do not have any wearing detection, which means we do not have automatic play/pause functionality.
Looking at the carrying case of the TOZO Open Buds, this doubles as both a case and a charging dock for your earphones. Unfortunately, it is not compact by any means. With measurements of 95mm in length, 59mm in width, and 28mm in width when closed, this may fit in pockets, but it is also noticeable. The case alone weighs 56g, which again is heavier than your typical true wireless carrying case. The top shell opens easily and is held closed with integrated magnets. On the front there is a single multi-color LED to show the battery life. This turns on when you open the case or plug it in for charging. The light is white in regular operation, but changes to orange when the battery is low. On the back, we have a USB Type-C port to charge the case. Unfortunately, we do not have wireless charging capabilities on the case.
For pairing, the TOZO Open Buds will be automatically in pairing mode when the case is opened up. Once connected, these earphones will automatically pair to the last mobile device it remembers that is available for pairing. However, if you ever want to reset your connections, you will need to place both sides in the case and press the small circular button at the front for eight seconds. Overall, most true wireless earphones have some form of quick connection, and the Open Buds are no different.
The TOZO Open Buds have lithium polymer batteries on each side and inside the clamshell case. Each ear has a 70mAh battery, while the case carries an additional 600mAh. According to TOZO, we should have a battery life of 12 hours of playback with an additional 30 hours for a total of 3.5 charges. These numbers on paper are quite good, but expected given the size of both the earphones and the case. Most phones, whether running Android or iOS, will report the battery life in the operating system, so you can rely on that or the mobile app to figure out how much life remains per charge. TOZO also reports charge time to be around 1.5 hours, which is reasonable.
The TOZO application is available on both the Google Play Store and the Apple App Store for you to download to your mobile device. On the main page, the app reports the battery life for each ear. It offers the ability to see more changes on the cogwheel as well as the current equalizer settings. Pressing the cogwheel will let you see options to change the touch controls, leading to the second screen. As you can see, you can choose different functions for the different number of clicks and the long press functionality. You cannot change the behavior for calling functions, although this is not too surprising. Furthermore, you can update the firmware for the earphones, but we were already on the latest version available during our review. The third page shows the different equalizer options available with the Open Buds, but unfortunately, you cannot create your own. Otherwise, TOZO also uses this app as their own store app so you can browse other products and see order statuses in the other tabs from the main menu.
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware and Software
3. Subjective Audio Analysis