what do you mean by better sound? Do you want your headphone to sound more open like your speakers? If so that is not really sound quality difference rather judt general sound stage difference between headphone and speakers. If your headphones are too quiet, you need an amp, if your motherboard don't have a good dac you could get one to. Or as other suggested in the comment you could eq your cans wiht something like the Apollo equalizer.
what do you mean by better sound? Do you want your headphone to sound more open like your speakers? If so that is not really sound quality difference rather judt general sound stage difference between headphone and speakers. If your headphones are too quiet, you need an amp, if your motherboard don't have a good dac you could get one to. Or as other suggested in the comment you could eq your cans wiht something like the Apollo equalizer.