Where is the most popular secret to teach you to r

Teach you to identify the secret of cheap MP3 where

the noble MP3 of the past has finally stepped down from the altar. With the increasing number of OEM products and imported goods of unknown origin, MP3 seems to have moved from the era of "huge profits" to the era of "inferior quality" So today, xiaom will talk to friends about what should be paid attention to when buying Mp3:

first, the key to determining the sound quality

for MP3 Walkman, the decoding chip is the most critical part, and even directly determines the final sound quality performance. As a lossy compressed MP3 format, excellent decoding quality can make up for the loss of audio signal to a great extent. On the contrary, the low-end decoding chip will further lose the encoded information of MP3

at present, most MP3 chips in the market mainly include saa7750/saa7751 of Philips, stmp3410/3412 of siemens

, tcc730/tcc731 of techips, S3C2410 of Samsung, etc. In terms of cost, the gap between these decoding chips is very large, and the resulting effect difference is also very obvious.

generally speaking, the medium and high-end MP3 with more than 800 yuan adopts the chips of Philips or telematics, while the middle-end products mostly use the decoding chips of sigma and Samsung, and a few low-end products use the decoding chips of STM or Sunplus. From the naming method, we can see, Some manufacturers' chips adopt the form of dual chips, while some manufacturers have just used single chips. The advantage of dual chips lies in the separation of decoding chips and control chips, which can bring more excellent decoding effect; Although a single chip loses sound quality, it can simplify the structure and make it easier to manufacture Mini products

most low-end MP3 players use low-grade chips, so the overall sound quality performance is certainly not very good. It is not possible to change a pair of high-end headphones to solve the problem. In addition, the decoding chip also determines whether mp3 can support wma

VQF RA MP3 Pro wav and other formats. A few low-end products use the technology of previous years, and such products can't even support the high encoding rate MP3 decoding of 320kbps

second, auxiliary chip

if the decoding chip is the soul of MP3, other auxiliary chips are needed to make an MP3 really work. Among them, D/a conversion chip and power amplifier chip also play an important role in the overall structure of MP3 player

the D/a conversion chip is like the first barrier after the decoding chip. An excellent D/a conversion chip should be able to realize 16bit conversion, and integrated with a digital filter, so that the output value is the quality of the product. The sound is more pure, while the ww8725ed D/a conversion chip used for many cheap MP3 players is far from reaching this standard

in addition to the D/a conversion chip, we can also see the power amplification chip in the MP3 Walkman, which is mainly used to amplify the signal output to the headphone interface. An excellent Headphone Power amplifier should achieve accurate amplification, and use the acoustic principle to eliminate the noise as much as possible. However, the amplifier indicators of some cheap MP3 players are seriously low, resulting in large volume output, but obvious distortion. There are many chips in MP3, including power supply chips, LCD control chips, etc.

, cheap MP3 players have shrunk to varying degrees in all aspects, resulting in poor overall quality performance

third, the performance of stability: flash memory chips

are no more than MP3 players from waste plastic recycling plants. The signal process in the playback process does not involve mechanical movement at all, so generally speaking, as long as there is no problem with flash memory and memory card, there will never be skipping and other phenomena during playback under normal circumstances. However, there may be defects in the built-in flash memory chips in MP3 nowadays. From the overall cost analysis, flash searchtype=1'

target= among low-end products, the alligator department will regularly verify them every year_ Blank flash

the proportion of ROM flash chips is even higher than MP3 decoding chips. Sometimes a few manufacturers naturally choose inferior products to further control costs

many users find that their MP3 cannot recognize the audio file after being deleted and written to the file many times. At this time, they have to reformat it. A long time will naturally affect the reading and writing speed of MP3, and there may be skipping sound when playing

green, ecological, health and safety have become the lifeline and super binding conditions for the development of the plastic processing industry.

IV. details

low end MP3 players generally do not use lithium-ion batteries, but use No. 5 or No. 7 batteries. Due to the poor performance of the control circuit and the energy-saving design of each chip, some cheap MP3 players can only play for less than 2 hours when using ordinary batteries, This is naturally unacceptable. The short power supply time is only one aspect, and the huge heat output is also frightening. At this time, the stability can be imagined