Q: Why when I connect my audio technica im70 earphone to my iphone the sound quality is same with my apple earphone ?

My experience with Apple's earbuds is that they are pretty good. If you are having a problem with the Audio Technica headphones, you will want to contact them for assistance.

Full disclosure: I wear hearing aids and so I have to listen to audio via headphones or earbuds with the volume jacked up.