Shoutcast Stream Played on Android Phones : Low Quality -

i have mediaplayer service inside app . can play shoutcast streams. selling app different customers have different quality , formats of broadcast.

my own radio can played without problem has following properties:

server status:  stream requires registration in shoutcast directory. listeners allowed , stream act private until resolved. stream status:  stream @ 96 kbps 4 of 500 listeners listener peak:  26 average listen time:    27 minutes 2 seconds stream name:    **** fm content type:   audio/mpeg stream genre(s):    music 

however, today experienced interesting issue . 1 of customers said quality of sound coming main speaker bad. checked on phone , bad. interestingly , when plug in headset, quality turns out how should be. 1 more interesting thing stream played without problem on tablets' speakers.

the customer's shoutcast server has following properties:

server status:  stream , private stream status:  stream @ 96 kbps 0 of 300 listeners stream name:     content type:   audio/mpeg stream genre(s):    misc 

what source of problem ? there way solve it?