I'm aware that headphones / speakers are more important, thanks for pointing out. I have something that's supposed to be decent for once, Beyerdynamic MMX 330 Pro, a bit pricey for headphones without extras. While I detect difference between both onboard audio that I have (on ASUS M3N78) and dedicated sound card or combination of old/new headphones/sound card, I can't say it's a very big difference, more on the mild side. Clarity is still in favor of more expensive gear. I was comparing listening to some music tracks stored in high quality FLAC files.
Someone here mentions that old Audigy 2 sounds better than Rx, that the latter sounds weak.
https://old.reddit.com/r/SoundBlasterOfficial … a_disappointed/
There is a saying "Don't believe everything you read on the internet", but with sound, it's especially like everyone lives in their own world.
X-Fi MB3, yeah, it's the point that it works with any sound card. Although it looks like it can't deal with applications that support outputting multi-channel sound if real sound card only supports stereo (eg. laptops) unless there was an update that I'm not aware of. In that case, you can't choose more than stereo on X-Fi MB3 either. That software was retired, can't buy it anymore and even if you bought it, can't activate it by usual means anymore.