So, about a week ago I received the Creative Titanium HD and Schiit Magni to pair with my X1's. I'm still enjoying my X1's although through several days of anal listening I noticed that the right channel was about 4% points louder than the left channel on my pair. What that means is if windows volume is at 100% then the right channel needs to be at 96% for equal loudness in both channels. Kind of annoying but at the moment Amazon Italy does not have any X1's in stock, so I can't return them for a replacement, and Philips themselves also do not have any replacements in stock so I can't get a replacement yet either. At least I have a 12 month warranty and when Philips gets another pair in stock I will exchange them. Still, it's not as bad as it sounds because when listening to music in stereo, as we all normally do, then I can't really notice unless I'm listening for it.
Creative X-fi Titanium HD
Anyway, the first thing I will get over with is the Titanium HD sound card. The Asus Xonar Essence ST easily sounds better for music and movies. The X1's are quite transparent and respond to better equipment and while the Titanium HD apparently has pretty decent internal components, the extra attention to detail that goes into the creation of an Essence ST is noticed with these headphones. Music is just clearer and crisper on the Essence ST, even when you are running the Titanium HD in ASIO mode with the Foobar ASIO plugin. The Essence ST and WASAPI just does it better and has a more airy sound stage somehow than the Titanium HD. Additionally, I prefer movies on the Essence ST because of Dolby Headphone. CMSS-3D and THX True Studio Pro do not sound very good at all on the Titanium HD when watching films. It's just too artificial for my taste. Dolby Headphone with the X1's is like being in the movie theatre itself.
Gaming wise, the Titanium HD defeats the Essence ST pretty convincingly in terms of sound positioning and noise effects. As a result, the Titanium HD is quite a bit more immersive because of how convincing the virtual surround is. However, the sound quality when enabling CMSS-3D is much more noticeably degraded than when using Dolby Headphone DH-1. The CMSS-3D function brightens up the X1's and any other headphone to very unnatural levels, but the enhanced mids and highs is what helps you hear things like footsteps, bullets and other sound effects which will help you be more competitive when gaming. Dolby Headphone DH-1 on the other hand does not alter the sound signature too much but does muddy up the sound a bit. The same footsteps, bullets, etc. that you can hear so clearly on the Titanium HD are muffled and veiled on the Essence ST, and Dolby Headphone DH-2 and DH-3 add so much reverb and extra bass that you might as well just forget about using those two settings for gaming because everything is a muddled mess.
The Titanium HD also has a much better sound stage with the CMSS-3D function and sound very airy and open in comparison to Dolby Headphone. Accuracy is also very good too. You can hear very convincingly exactly where a sound is coming from in the virtual 360 degree field. With Dolby Headphone you can hear relatively accurately but pinpointing the exact location of the sound is not so easy. This all probably has to do with a lot of things such as the algorithms used in CMSS-3D and Dolby Headphone and the fact that the Titanium HD supports EAX 5.0, OpenAl and other forms of hardware acceleration, whereas the Essence ST is mostly software with broken EAX 2.0.
Feature-wise the Titanium HD wins by a landslide. The creative software lets you tweak almost anything compared to the relatively basic layout of the ASUS software, and it even supports bit-perfect playback for music which is a big plus as I have both 16-bit 44.1khz files and 24-bit 96khz files. I really enjoy the extra functionality of Creative's software and all of the features which the Titanium HD supports on the hardware end. BUT, one thing which is really annoying is that if anything is plugged into the Titanium HD's headphone jack, you cannot switch to the plugged in speakers which are using the line out. With the Essence ST you just opened the Xonar control panel and selected your output source and the card made a clicking noise and all was good to go. The fact that at the moment I have to physically unplug my headphones every single time I want to use my speakers is really annoying. And since the Schiit Magni only has a headphone out I can't connect the speakers to it either and switch from there (which you can do on the O2 and other desktop amps).
In conclusion, I wish that there was an all-in-one sound card out there that had the Titanium HD's hardware and software features, but also had the higher quality components of the Essence ST and support for Dolby Headphone for movies. Oh, and one that allowed you to switch between headphones and speakers without plugging and unplugging all of the time!
Schiit Magni
Let me start off by saying that the Schiit Magni looks very nice and works just fine with a 220v to 120v converter here in the UK for all of those people following the Schiit Magni threads and asking this question every other post. It's also extremely powerful. I can't really run the windows volume at 100% and run the X1's through the Magni because the sound gets too loud before 10 o'clock (This reference is assuming that your zero-volume position on the Magni is at 7 o'clock and your max-volume position is at 5 o'clock). I run the Windows volume at between 60% and 70% and then turn the Magni up to between 11 o'clock and 12 o'clock. The Magni also lets through a bit of sound at zero-volume when you have the windows volume maxed out (like a loud whisper). And unfortunately, the Magni has very bad channel imbalance from zero-volume to about halfway between 8 o'clock and 9 o'clock. It starts centered at zero-volume and then all of the sound moves to the right channel, and then slowly comes back to the centre when you are halfway between 8 o'clock and 9 o'clock. From that point onwards the Magni has even channel balance all the way to max-volume from my testing. Finally, the Magni gets about as warm as any modern cell phone after you have been multitasking on it for several minutes.
As for sound quality and what it did to my X1's there are two things. First, the sound cleared up quite a bit when running through the Magni. As others have stated, the sound is very clean. The X1 bass was also noticeably tighter and quicker (which I liked a lot). The recessed mids were brought forward a touch and the highs went from good to very good. Vocals sound much better through the Magni now than they did prior to the amp and I'm very glad for that. Second, the Magni does reduce the sound stage in music but not by a whole lot. It's more in your head but the instruments still retain the depth they had before the amp so at least the airiness is still there, but it feels closer than without the amp on the X1's.
EDIT - I think this is because the opamp's used on the Titanium HD and Essence ST have a different sound signature than the Magni amp itself. So when you are just plugged directly into the headphone out you get a different sound.
In gaming and movies the amp didn't affect the virtual surround technologies of CMSS-3D or Dolby Headphone at all. Positioning remained very good, the sound stage for CMSS-3D and Dolby Headphone also seemed the same as without the amp, and the sound was a bit clearer.
The question is, will I keep the Magni? Hmm...well I don't mind the sound signature and thought that it really made the X1's sound like a much more expensive headphone. Yet, I think it may be a bit too powerful for the 30 ohm X1's if you want to run Windows volume at 100%. The amp felt like a much better match for my Beyerdynamic DT 880 250 Ohm headphones in terms of power delivery (sound signature was too bright though on top of an already decently bright headphone). Moreover, if I do end up keeping the Titanium HD I think I would want an amp that also has line-out support along with headphone out support so that I can switch my source manually on the amp, rather than having to unplug the headphone cable all of the time (stupid Creative engineers).
Brief Conclusion
In short, the Titanium HD has a lot going for it due to the gaming capabilities and tweakability of Creative's software. It falls short in the music department compared to the Essence ST and I prefer Dolby Headphone for watching movies. The Schiit Magni has a very nice and clean sound signature that emphasizes mids and highs a bit which really pairs well with the relatively warm sounding X1's. Yet, the Magni is very powerful and might be a bit too powerful for the 30 ohm X1's and would probably be happier powering headphones which have an impedance over 100 ohms.
I think I might end up keeping the Titanium HD but will probably switch out the Magni for something else. Does anyone have any alternative recommendations of a low impedance amp which sounds similar to the Magni and O2 and has both a headphone out and line out? I'm willing to pay up to 3x the price of the Magni which is about $300.