[realcake]

I am looking into getting the Ultrasone PRO 900, and with it, I need to get a sound card or amp/dac. My only requirements are that the card doesn't bottleneck the frequency range of the PRO 900, 6Hz-42Khz, and that they are surround sound capable, since I like to game as well. I have looked at ASUS and CREATIVE's selection, but they all seem to go down to only 10Hz. I am not as familiar with any decent external AMP/DACs that offer surround sound, so if you know of any please let me know, along with any sound cards that meet my requirements. Thanks!

 

[PurpleAngel]

I'm not too knowledge about the Hz-Khz stuff, but I'm guessing the "6Hz-42Khz" is more of a marketing promotion, then something that can used (taken advantage of) in real life, but I'm just guessing.
Do you have a budget for the DAC/Amp or sound card?
What is the make and model of your computer's motherboard?
 
External DAC/amps do not come with any surround sound features.
External sound cards offer headphone surround sound, but an external DAC/amp will offer better audio quality.
A (low cost) internal sound card (PCI/PCI-E) combined with an external (optical) DAC/amp, is the best setup for gaming with good audio quality.

 

[realcake]

Ah, ok, I see, thanks.

 

[cel4145]

Below 20hz bass is bass that mostly you feel, so kind of unnecessary on headphones. The human range of hearing is generally described as 20hz to 20khz. So you don't really get benefit out of headphones going higher than 20khz. Moreover, that's why electronics (soundcards, amps, dacs) tend to be rated for that range.