Gary C., Jun 14, 2019 : The OnePlus 7 Series was officially introduced to public, and everyone knows about the new product: the customized fluid screen, fast and smooth, redefining lightness and smoothness. These are all visual experiences, and today we want to talk to you about its audio experiences. The production of any piece of music goes through the processes of composition, arrangement, mixing, mastering, monitoring the quality on headphones or sound boxes, various adjustments and optimizations. So do the ringtones. But that’s still not enough. Why? If you listen to any sound through headphones or a sound box, unless it is of terrible quality, it will sound okay with no distortion or break. But the phone speakers are different. As the volume gets louder, and there are more high and low frequencies, distortion can happen due to tones or pitches. This is mainly due to the low-power nature of the mobile phone speaker, narrow frequency range and small sound chamber (the cavity in which the speaker sounds). In order to break through these limitations, it is necessary to debug sounds one by one. But considering that different phones rely on different components, the end result would vary, thus a more precise adaptation is needed. The actual ringtone must be then tested through the phone’s loud speakers. The most basic means to do so is by adjusting the volume, turning the volume up or down the volume based on different situations. Adjusting a sound greatly varies depending on its nature, so many approaches need to be considered: Some ringtones that have frequencies beyond the speaker's frequency response range requiring further adjustment. We have to attenuate the frequency below 100-150Hz and turn up the volume as a whole. If the result is not that satisfactory, with the sound still being stuffy, we then make some gains in the middle and high frequency to improve the loudness and brightness. For certain harsh sounds, attenuation needs to be implemented within the high frequencies. For some sounds that lack detail, they require to be supplemented with the compression effects for some dynamic processing. For sounds that fail to deliver the expected satisfactory performance, they need to be rearranged, such as raising or lowering the overall pitch. For sounds that are comfortable to be heard on the headphone but appears too crowded on the phone, some unimportant chords need to be deleted to make the percussion section simpler. On the other hand, sometimes the main melody sounds too thin, so superposition of different timbres from different tracks might also be required. Besides, these timbres must be characterized with different acoustic images and mixed with different equalizations in different registers, in which case the sound would be fuller and three-dimensional. Before optimization: After optimization: The new product is equipped with super linear dual speakers so there is a qualitative leap in the sound quality and volume compared with previous ordinary speakers. We have done a more detailed treatment based on the characteristics of the two speakers. For example, lower frequencies may not be good at the top speaker, so that part should be moved slightly towards the right sound image, which helps preserve the bass effect as well as avoid the overload for the top speaker. Likewise, for sounds that are not prominent enough for the stereo, widening the sound field by distancing the sound images would also help to improve the prominence. Here we introduce the debugging for the default SMS sound "free". As for its production process, I have composed a post about it on our Chinese blog, you can check it here (in Chinese). This sound has a unique style, but the actual effect on a mobile phone speaker is not that good. In the new product, we changed the tone and adjusted the pitch. The result is good, but the ringtone changes a lot compared to the original. After trying various methods, there still wasn’t an actual improvement. I started conducting an experiment with a lot of sounds. Finally, I tried to superimpose the sounds by adding a timbre rich in high frequency to the original one. Through proportionally mixing the two sounds, equalizing and adjusting reverberation, I managed to find a closer tone which is featured with a harsh sound head producing a sense of tension. After repeatedly adjusting the range and balance, in the end we have struck an appropriate equalizing by making moderations to the sound images based on their tonal characteristics. Voila, the new Free! Free ringtone - old version Free ringtone - new version For previous generations of products, quite a few of our users complained about that the cell phone vibration motor not being good enough. Now, the phone is equipped with both the dual speakers and horizontal linear motor, which brings great improvement in the visual, auditory and even haptic experiences. Generally speaking, the vibration of the mobile phone motor is prefabricated with a fixed rhythm, which means that the vibration rhythm is constant regardless of the rhythm of the ringtone. This time, we developed a dynamic vibration mode, allowing the motor to automatically follow the rhythm of the music. But the insufficient precision gives rise to various situations: skipped vibration where vibration does not happen as expected; false vibration where unintended vibration happens; monotonous vibration intensity where there are no variations or changes in the vibration. To this end, we have specially created a unique vibration rhythm for each ringtone and made more subtle optimizations according to the rhythm and strength of different sounds. In order to achieve the best results, we conduct repeated debugging with our suppliers, in an effort to make the vibration more user-friendly. The supplier couldn't help commenting: "You really carry it through so carefully. We have never done anything like this before!" As above, looking forward to your feedback on user experience. Never Settle.