How to program the bluetooth chip in my xb43

I had an SONY SRS-XB43 that won't power on and I traced the fault to the bluetooth IC MT2811 which I couldn't find a replacement for so I took same IC out of an XB23 and put it in the XB43 and it now powers on but the sound is not so good and it still identifies as an XB23. Please I need to know if anyone knows how to reprogram these speakers and if possible the firmware for the XB43 to be loaded in the MT2811