1. Built-in flash memory: this should be the most attention to the majority of users of the parameters. In fact, it is like a computer's hard drive, determines the size of your MP3 capacity. From the early 16M, 32M to the present 64M, 128M, 256M, and has emerged 512M. In general, we often use the 128KBPS compression rate of MP3 each about 3-5M.
2. Expand the memory: the equivalent of their own to increase the capacity of the same computer. The difference is that this increase in flash memory according to the different MP3, MP3 you can have CF card, SM card, MMC card, SD card and other options. CF card is used in early MP3, and now because of the size and power consumption reasons, has been rarely used; SM card should be regarded as the most used on the MP3 expansion card; MMC card is the second generation of expansion cards, SD card is developed on the basis of the MMC card, so it is also backward compatible - that is, if your MP3 support SD card, then it can also generally support MMC card, but in turn MMC card plug Slot MP3 does not support SD card. In addition to the above list of several cards, SONY also push a memory stick expansion card, MP3 generally only used in SONY models, rarely see other products.
3. MP3 support format: sampling rate, the general support 44.1kHz, very few MP3 players support 48kHz MP3 files; bit rate, MP3 files can be used is generally 8 ~ 320kbps, but different MP3 players in this area to support the range is not VBR, dynamic coding, now out of the MP3 player most of the support VBR, the old machine in this area less, this is also a good support, MP3 because it can be better in the same sound quality Experience.
4. Support WMA: WMA is Microsoft to promote a format, it can be in the same sound quality than MP3 format files smaller, so this function is equal to disguise increase MP3 player capacity. Its compression rate is generally 5 ~ 192kbps. Here to note that the problem is that with Windows with the WMP own compression, there is a copyright protection option to be removed, otherwise the pressure out of the WMA can not play on MP3; there are general charges to download the WMA file, which have encryption , MP3 Because different sites using different encryption algorithm, so for now, there is no uniform and convenient way to crack. This point also need to pay attention, do not complain about old - how my MP3 obviously support WMA format, how can I not play.
5. Other file format: This is more mixed, such as ASF, WAV, in fact, from a practical point of view, the current play files MP3 and WMA is also easier to use, the other either not popular, or too large, no practical significance.
6. FM: FM radio function. This is an additional feature of MP3. MP3 From a practical point of view, now the MP3 is not very good to do this, it should be said that not as ordinary radio - receiving range, accuracy, and so there are gaps, can only be said to be a useful supplement. Of course, if you focus on this function, there are also doing good products. But in general, the proposal is only a reference for the purchase of MP3 - really want to listen to the radio, spend tens of dollars to buy a separate said in front of the ordinary radio, MP3 absolutely more money than to increase this function to be cost-effective. In the specific models, for FM, different products are broken down: whether you can save the selected channel, you can save the number of channels, MP3 stereo and ordinary channel can set their own or set by the machine.
7. Recording function: divided into external records and recorded. External recording, that is, direct recording of voice and other external voice; recorded is recorded FM function. Direct recording, using audio cable, recording CD, tape drive and so on. (But the use of MP3, WMA format recording, but because of the encoding or not Strong, so the effect is not good. Therefore, it is recommended that unless the recording of English textbooks and other content does not pay attention to sound quality, or will be disappointed. On the issue of recording accuracy, the same as the FM function, different models have refined options: whether to adjust the recording frequency of the recording, MP3 whether the external MIC, recording file format (ADPCM, MP3, WMA or Other manufacturers custom format), the recording file can upload and play (for the need to save the recording file and edit the users, this is significant).
8. Repeat function: from the current MP3 products, the basic should have the following functions: single cycle, multi-song cycle, fast forward, rewind, A-B repeat (any point repeat). There are also some advanced features, and now there are products in the above added a new feature: such as voice speed (some models can be adjusted between 50% -200%), according to set the number of seconds to read, the sound Synchronized text.
9. Mobile storage: divided into no drive and drive two. Most of the MP3 machine for copyright protection considerations, requiring the use of own management procedures to achieve MP3 and computer files between the upload and download. MP3 is now out of the general non-music format files are supported file management, that is, MP3 you can achieve the upload and download these files. And whether the need to install the driver, only affect the specific use of the environment - if it is a fixed computer, even if the drive does not matter; if it is often transferred between different computers, of course, recommended non-drive type, after all, eliminating the installation management program The trouble. (Here is not relative to the operating system after the WIN98)