The bass of PX 100 is much better than that of PX200. I used PX 100. When I first bought it, I thought for a long time whether it was 100 or 200. Then I went to the store to audition before I got PX 100. It's hot now, so I'll use CX400.

MP3 recommended iaudio, made in Korea. His sound effect is really not covered. His BBE is the only one in the world with its own patent. Very good, especially classical music. Very shocking, and it is the first i7, classic. Moreover, IAD Studio officially recommended Senhai's headphones as standard, which really improved a lot compared with the original headphones.

The sound quality of ipod is just like boiled water, insipid and tasteless.

Sony can only play with its own headphones.

Kenwood and BEOSOUND2 cranes, but they are too expensive.

The sound quality of PS: CD and HD is still better than that of MP3, but now it has declined because of its large size, inconvenient carrying and inconvenient song updating.

The above answers are provided by LzCules' personal experience. I hope others will not copy and respect the fruits of others' labor. Thank you.