Radio sound issues

Question

I have a 2003 acura mdx. Radio worked but CD player n tape player did not work only radio. I went to a junkyard where I found the same vehicle and pulled the radio plugged it in just as the other radio was plugged in and got all the alarm reset codes and the radio plays but u got to turn the sound to max volume to hear the radio or CD or tape player. Same factory system just different radio? What could be the ssue