So, I just bought a 8-speaker sound system. I usually game/listen to music on headphones or tabletop mic's, but my on-board sound is dying, so I figured this would be the time to try out a soundcard for the first time.
The Xonar will offer you proper 7.1 audio while the Soundblaster Z is limited to 5.1 channels but has a better AMP for when you use headphones, both have 116dB SNR. I have a Soundblast Z myself and let me tell you, it sounds good but Creative's driver support is absolutely hideous.
I understand Asus is slightly better in the driver department but there's also a couple of modded drivers for the Soundblaster Z that help people having problems with the official drivers.
It boils down to what you prefer in terms of features.
My budget is $50-$70, willing to go lower if I can get away with it . It's mainly to replace my on-board sound, which is dying right now, but I want to see if it will make a difference with my 8-speaker setup that I'm about to try
The Xonar will offer you proper 7.1 audio while the Soundblaster Z is limited to 5.1 channels but has a better AMP for when you use headphones, both have 116dB SNR. I have a Soundblast Z myself and let me tell you, it sounds good but Creative's driver support is absolutely hideous.
I understand Asus is slightly better in the driver department but there's also a couple of modded drivers for the Soundblaster Z that help people having problems with the official drivers.
It boils down to what you prefer in terms of features.
If your 8 channel set up is good quality, I would give the Xonar a try, no headphones surround emulation will beat the real thing, I have a good 5.1 setup and these days I use headphones only for online gaming, no more. I have nothing bad to say about the Soundblaster Z in terms of sound quality, quite the contrary. Nevertheless, I did have to fiddle with a lot of different drivers and swapping slots on the mobo until I managed to get it stable.
There's a thread here in which you will be able to see potential problems you will be facing:
Between the ASUS Xonar DX and the Creative Soundblaster Z, I'd almost always recommend the Z unless you can find the DX for about $50. It's still a VERY solid option, but it IS getting on in years now. The amp the Z has also makes it a more attractive option.