Both depend on what you like and what you use. If you pay attention to appearance and exercise regularly, you can choose SA28 and D29, but if you just listen to pop music, SA28 performs well.
As far as a single chip is concerned, Osun chip will be much better for oppo d29, but note that the latest sound effect of SA28 with Philips is called "flying sound", which is the same as that of the original Philips LIFE VIBES, but it is several times stronger than the previous generation. Let's just say that sigmate 37 10 can't catch up with Philips PNX 102 chip in chip level. However, after the sound effect of "flying sound" is used, it can directly compete with PNX1KLOC-0/using LIFE VIBES in terms of sound quality (without noise floor), but even so, the selling point of this MP3 is not cost-effective compared with ordinary MP3. In fact, it is mainly aimed at the best sound quality and price combination of sports and fashion MP3 (SA28 has sports armbands, belts and protective covers, and 3-piece accessories, so you have to buy 3 pieces yourself (around 35 yuan). His sound quality is the strongest among all MP3 players using sigmate 37 10 chips. MP3 players using sigmate 37 10 chips are generally 2G 199, such as X9 V7 VX898+, and 2G is about 330 yuan. Look at this picture. We know it doesn't invest much in sound quality. In addition, it should be noted that its chip sigmate 37 10 belongs to the middle and low frequency chip, and its music style is very suitable for pop music, but the performance of rock and treble is not very good.
Oppo d29, look at the shape and you will know that it is not a sports MP3, but a fashion model at most. It doesn't have too many music style restrictions, and it is more flexible to use Osun chips. In addition, OPPO's own DBEE sound effects and supported lossless formats are universal in music performance. If the overall sound quality is definitely worse than SA28, first of all, DBEE is mainly aimed at bass. At this point, the sound effect of "flying sound" can't be better than it in bass, so it is called real sound effect because it strengthens the analytical power, not the degree of some parts. Compared with others, "flying sound" strengthens the sense of space and the loss of high frequency, while DBEE strengthens the potential of bass such as drums. The two on the chip are also the strengths of OPPO. Needless to say, Ousheng was originally positioned in the middle end, and the title of the chip with the highest cost performance could not be worse than sigmate 37 10. In addition, D29 supports lossless format music. If D29 uses lossless playback music, it can offset the compensation part of "flying sound". OPPOPAD has dual voiceless and noise-reducing design, with signal-to-noise ratio >; 93dB, while the signal-to-noise ratio of SA28 is only >: 85DB (calculated according to the standard deviation at home and abroad). The sound quality of a product largely depends on the signal-to-noise ratio, which proves that the sound quality of D29 is better than that of SA28.