In fact I am against having sound period on a high end motherboard. IMO it has about the same amount of business on a motherboard as Intigrated Video. the quality of the sound is always lacking (interference from other mobo components) and it is fairly cpu intensive. a $20 SBLive will outperform just about any intigrated audio.
just my 2c, take it for what its worth.
I have a DFI Lanparty board which I used the onboard sound module before I installed my SB Audigy card and it was pretty impressive sounding. I use Altec Lansing MX5021 speakers. I had to remove the module though to fit my huge zalman cooler on the board.
De Do Do Do, De Da Da Da, that's all I want to say to you ....
Yes they should . .and if not onboard then I want a live band or symphony outside the box so my friends can ask: Is it live or is it DFI ? . . . . just kidding . . . DFI sound modules (DFI LanParty Expert) are good . .but . . if you want / demand superior sound then sound cards are a must with all motherboards. The sound cards do sound . . and well . .they take the tasking away from the CPU. There is just so much "territory" on a motherbaord for all the chips / circuits. If you have a great dedicated sound circuit / chip then you eliminate something else that perhaps makes the motherboard an outstanding computer. Want a great stereo with a computer attached or a great comptuer with a sound module ? You can have a great computer with a great sound . .but you have to bring your own sound card . . an easy and not too painful solution.
I prefer onboard sound, even moreso now that slots are getting fewer.
Onboard sound has gotten so good today, that unless you are mixing and recording music professionally, you can not tell the difference.
I hook mine up to a Sony 110watt ch reciever with two Bose 201 bookshelf speakers. Sounds great.