5.1 sound from HTS3538/12 via SPDIF

Hi all,
I have 47PFL4007/12 TV and HTS3538/12 home theatre system. And I am planning to buy a mediaplayer (HMP5000) but have a concern. Since yesterday I tried digital optical connection between Dark mania media player and my HTS but there were only RAW and stereo options via SPDIF. And the sound was too bassy even I changed all relevant settings(Subwoofer Volume, bass settings etc.) to bottom. I need to know whether there is multichannel(5.1) option in SPDIF of HMP500. Another question how can I decrease bass and increase treble in addition to bass/treble settings. May I use a potentiometer to set subwoofer volume externally?
Thank you for your answers in advance.
Regards,

Windows 7 110 1190br idt audio driver drivers download - 110 ... 1 x front panel audio header 12. ... High Definition Audio 2/4/5.1/7.1-channel Support for S/PDIF In/Out Support .... from your Home Theater System via a simple HDMI connection. ... Philips HTS3538/55 Home Theater Firmware 34

Thank you Alex001
I upgraded to V34 but could not understand other driver "Windows 7 110 1190br idt audio driver drivers download - 110 ... 1 x front panel audio header 12.."
Can you please give more detail, Where can I download from and How I can upload to my HTS?
By the way I am not able to get sound from the speakers tough I upload the final firmware again and reset the HTS.. Even I get no sound while setting speaker volumes..Do you have any idea about the reason? I have sound from tv speakers when I play something in HTS..But 5.1 is silent. I will ask technical service
Thank you.