Page 3 - Subjective Audio Analysis
Reviewing audio devices require extensively trained ears, lots of experience, and sufficient technical knowledge. Even for the experienced auditioner, it may prove challenging at times to obtain an accurate evaluation of a product without a thoroughly familiar product to use as a simultaneous reference. Furthermore, many self-proclaimed audiophiles are susceptible to biased write-ups due to placebo effects from false advertising. While I am not going to even try to claim that I am the only trustworthy or best evaluator for sound, it is fact that most computer review sites have editors who are insufficiently trained in reviewing audio equipment. Give them practically anything and all you will read about goes along the line of "good bass, nice midrange, awesome treble, really clear sound, 10/10". While there are many knowledgeable audio reviewers at various respected online media outlets, they are by far the minority.
As I have mentioned in my past audio reviews, there are really no true objective measurements for sound quality. As the evaluator, however, I will put it through a series of subjective tests to try to come up with the most objective rating possible. Yes, it sounds like a paradox. For all tests, I used an Apple iPhone 15 Pro over Bluetooth 5.3 with support for SBC and AAC. After over 75 hours of break-in time -- well above typical required time -- I put the TOZO Open Buds to the tests. All test tracks are high-quality CD-equivalent files.
Starting from the lower end, it should not be a surprise the TOZO Open Buds were a bit lacking in certain areas of the bass. This is not to say there was no bass present, but due to the lack of seal in your ears, anything in the lower end felt lacking in depth and definition. As for the bass that was there, this was more in the mid- to upper-bass. It almost felt like they were compensating for the lack of bottom bass, as this middle and upper bass was emphasized. Lines from the electric bass or instruments like cellos and tubas came through, but again felt hollow and muddy without any of its foundation.
As for the midrange, the TOZO Open Buds were a bit weak in this region. This region was not the smoothest with a greater emphasis in the bottom, a noticeable recession in the middle, and an increased emphasis back as we moved to the upper midrange. Instruments like pianos or acoustic guitars sounded thin and unnatural. It lacked the wooden resonance you might expect from these sounds. Vocals here sounded dry and even raspy. Overall, the midrange could have been improved in detail and saturation.
Moving to the trebles, the Open Buds had a bit of a peak moving up the trebles before falling off at the top-end. At times, instruments like violins and flutes really struggled to shine through at the highest end. This was partially an issue with the default balance, but the recessed nature at the highest end was also to blame. High-hat and cymbal crashes felt clashy and unclean. All in all, between the three frequencies, it felt like an upside-down W, with a peak found in the mid-bass to bottom midrange and another one at the high-midrange to low-trebles. Between there was a bit of a valley with some portions missing around there. Unfortunately, this gave a very uncomfortable balance to the overall sound.
One thing that you usually can get with an open design like the TOZO Open Buds is soundstaging. To an extent, this holds true for the Open Buds, as they provided decent width and depth. As your ears are not sealed by any physical barrier, the whole audio stage felt more open and livelier. The sound did not sound like it was coming from just inside my head, but rather more in my room. Imaging as such was decent, but I would say the unfavorable sound balance negatively affected the realistic image.
In terms of layering, the TOZO Open Buds was able to play everything I threw at it, but when multiple sounds were layered, the Open Buds struggled to keep the same precision or detail. Sounds became muffled at times because the Open Buds were unable to drive everything to the same degree of resolution. The frequencies were separated by the aforementioned dips and peaks, but this negatively affected the cohesiveness, as transitions between these layers were not smooth. Finally, the sound was not clean, with a notable muffle. Furthermore, there was quite a bit of static played when the earphones were turned on but not playing any sound.
As for sound isolation, the TOZO Open Buds are truly open and as such the sound does leak out. At 50% volume, it is not too noticeable, but anything louder and those around you will hear your song choices. Unfortunately, if you are in a louder environment, you will inevitably increase the volume. As such, I do not think I would recommend the Open Buds for any busy areas, like on public transport. I did like having them on while driving, as I could hear other cues while I was navigating the roads. Furthermore, the hooks hold really well and I was never able to shake off the Open Buds, which is great to see. I think for those exercising, such as biking or running, this would also be good for a secure fit while still having environmental cues.
For microphone testing, I recorded myself twice, first indoors and second outdoors. This would give a better idea of how the microphone performs in both ideal and less-ideal environments. Just so you know, I started both recordings by saying "This is a recording test with the TOZO Open Buds". On the indoor test, the microphone on the Open Buds were a bit muffled, but they did pick up my voice. It does not sound the most natural, but it will do the job for any phone call you have. As for the outdoor test, the microphones struggled a bit with the wind noise, as the start of my sentence was not picked up. TOZO does advertise their environment noise cancellation, but unfortunately, it thought I was part of the environment too. Otherwise, I actually thought it was pretty good at picking up my voice while rejecting the wind. As well, while it was -15c outside that night, the weather forecast reported a drop down to -30c later in the week, so this was probably one of the warmer evenings here in Calgary.
In terms of its wireless capabilities, the TOZO Open Buds were both good but not as good as it could have been. On one hand, it was able to hit around 7.5 hours at 50% volume before needing to be put back in the case. I was able to get approximately 3.5 charges in total from the case, translating into over 26 hours between full charges. Unfortunately, this missed TOZO's quoted 12 hours with a 42-hour full lifespan when incorporating the case. While it offered pretty good battery life, it was well short of the provided estimates by the manufacturer. Thankfully, charging the Open Buds seemed to be quite fast, as I was able to get it fully charged in around 50 minutes. Wireless range was good, as I was able to maintain a consistent connection up to 25m away with direct line of sight until I started to hear skips in music. In terms of delay, it was not noticeable when watching videos, but I did observer some lag when playing games.
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware and Software
3. Subjective Audio Analysis