I actually plan to do something similar and I think that you need to check "play stereo mix to optical out" under Advanced Features tab on the SB control panel.  I am not sure if you should have windows sound settings to output through SPDIF or speakers.  I think if you have it set to 5.1 speakers and have have play stereo mix to optical out checked in the control panel then it should work.  I am still waiting for my DAC/amp to be delivered so I can't confirm if this works, but give it a try if you haven't.

Firstly, I just wanted to say that this thread has been very helpful in a lot of ways and thank you for all the information! 
 
Recently I decided to upgrade my gaming sound experience and purchased a pair of Audio Technica ATH-AD700X with a Soundblaster Z.  I must say that this alone made a huge difference coming from integrated motherboard audio.  My primary use for this setup is strictly for gaming with headphones, which I do prefer the SBX features for this purpose.  I was so pleased with this that I started wondering if trading up my current Soundblaster Z for a ZxR would make a further improvement since the AD700X's have such a low impedance and the ZXR has the option to adjust this apparently.  In your experience, would the extra $100+ really be worth it with my AD700X's?  After reading a lot of pages in this forum I noticed that people have mentioned the impedance mismatch with my style of headphones and I am just curious if the ZxR would negate this difference and be a better pairing with the AD700X's? 
 
Any information is appreciated! 

The ZXR would only benefit you if you had headphone's that needed a stronger amp then what is on the Z,as well if you had a 5.1 setup that was good enough to take advance of the performance of the ZXR.  Also if you just using headphone's like the AD700x then the ZXR wouldn't be worth it, not even for the swappable op-amps, that 100 dollars can be used for something else instead. Then if you had headphones that would benefit from the ZXR stronger headphone amp then there would be better ways to do that, Same with wanting more audio performance.

haejuk said:

  I actually plan to do something similar and I think that you need to check "play stereo mix to optical out" under Advanced Features tab on the SB control panel.  I am not sure if you should have windows sound settings to output through SPDIF or speakers.  I think if you have it set to 5.1 speakers and have have play stereo mix to optical out checked in the control panel then it should work.  I am still waiting for my DAC/amp to be delivered so I can't confirm if this works, but give it a try if you haven't.

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Thanks, SBX Pro Studio seems to work now after I have followed your advice.

Just a small question.
 
I noticed in some screenshots that there's an option to choose low or high gain on the control panel. However, I use the Omni and I don't seem to have them. Is it because it's only for the PCI cards (Z, Zx, Zxr)? or am I updating my software/firmware incorrectly?

rxshadow said:

  Just a small question.
 
I noticed in some screenshots that there's an option to choose low or high gain on the control panel. However, I use the Omni and I don't seem to have them. Is it because it's only for the PCI cards (Z, Zx, Zxr)? or am I updating my software/firmware incorrectly?

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The option to change the headphone amp to low or high gain is only on the ZXR, as the ZXR uses a different headphone amp then whats in the omni and the Z/ZX. The headphone amp chip that is in the omni and Z cards is dynamic and supply it based on the amount of volume you use.

Thank you genclaymore.  That's pretty much what I was leaning towards.  In the off chance I decide to take that route with the ZxR, would you have any recommendations for headphones that pair well with it?  I'm not even sure if I really will go down that road as the Z with the AD700X's were already a vast improvement for me.  Again, this is primarily for gaming so really I'm still weighing if it's worth it in my situation to trade up my current setup for the ZxR and a different set of headphones.
 
On another note.  I have been tweaking SBX and the equalizer settings in an attempt to get a little more/cleaner bass with my headphones.  Any recommendations for adjusting these to achieve this?  When adjusting the equalizer for more bass would it be better to uncheck the SBX Bass option and allow the equalizer to take full control, including the crossover frequency, or maybe have a little of both? 

genclaymore said:

 
The option to change the headphone amp to low or high gain is only on the ZXR, as the ZXR uses a different headphone amp then whats in the omni and the Z/ZX. The headphone amp chip that is in the omni and Z cards is dynamic and supply it based on the amount of volume you use.

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Gotcha. Thanks!

If you were going to spend $100 more to improve the sound, I think it would be best to get an external amp as the output impedance on the headphone amps on all the Sound Blaster cards are very high.  The Sound Blaster Z has a 22 ohm output impedance which could be a bad match with lower impedance headphones, and the ZxR is better, but still high at 10 ohms.  Most people recommend that the output impedance of an amp should be about 1/8th of the impedance of your headphones.  It is actually more complicated than that and depends on changes in your headphone's impedance curve, but I don't want to get too deep into it.  You could get a decent external amp with a much lower output impedance for $100 or less I am sure.  I am currently using the AD700 (non-X) straight out of the SBZ and I am not disappointed at all.  It can get a little harsh at times, but I don't know if an external amp would solve that or not.

haejuk said:

  If you were going to spend $100 more to improve the sound, I think it would be best to get an external amp as the output impedance on the headphone amps on all the Sound Blaster cards are very high.  The Sound Blaster Z has a 22 ohm output impedance which could be a bad match with lower impedance headphones, and the ZxR is better, but still high at 10 ohms.  Most people recommend that the output impedance of an amp should be about 1/8th of the impedance of your headphones.  It is actually more complicated than that and depends on changes in your headphone's impedance curve, but I don't want to get too deep into it.  You could get a decent external amp with a much lower output impedance for $100 or less I am sure.  I am currently using the AD700 (non-X) straight out of the SBZ and I am not disappointed at all.  It can get a little harsh at times, but I don't know if an external amp would solve that or not.

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what's a good amp to go along with this? man this sound business is getting more and more expensive (what did I expect).
 
I'm probably getting a ZX (found a really good price)... was really tempted to go with the Omni (would I still need an amp?)
or would my Fidelio X1 not require an amp at all
 
(still unsure what to do with my Audinst HUD-MX1)

It does get more and more expensive, and as it gets more expensive you get smaller jumps in audio quality.  If you just want an amp on your desk for volume adjustment and a convenient place to plug in your headphones you could go with the Schiit Magni.  It seems to have a good reputation for its price and the specs look good as well.  I ordered one this week and am waiting for it to come in, so I can't 100% say this works great and is a huge sound improvement.  I am not too familiar with amps in this price range, but Fiio also makes good quality low price amps.
 
I haven't heard many good things about the ZX.  It is basically the same card as the Z, but you get that audio control module that some people reported ruins the sound.  I wouldn't tell you not to buy it straight out because I have no experience with it though.  Just what I have read (and that could be outdated).
 
Based on a quick look at the Fidelio X1's impedance graph at inner fidelity I think that an amp with very low output impedance would suit this best.  Apparently the stock cable also doesn't help as it has an unusually high resistance.

haejuk said:

  If you were going to spend $100 more to improve the sound, I think it would be best to get an external amp as the output impedance on the headphone amps on all the Sound Blaster cards are very high.  The Sound Blaster Z has a 22 ohm output impedance which could be a bad match with lower impedance headphones, and the ZxR is better, but still high at 10 ohms.  Most people recommend that the output impedance of an amp should be about 1/8th of the impedance of your headphones.  It is actually more complicated than that and depends on changes in your headphone's impedance curve, but I don't want to get too deep into it.  You could get a decent external amp with a much lower output impedance for $100 or less I am sure.  I am currently using the AD700 (non-X) straight out of the SBZ and I am not disappointed at all.  It can get a little harsh at times, but I don't know if an external amp would solve that or not.

Click to expand...

What are your thoughts on the Sennheiser HD 598 or 558's vs the AD700's when they are used primarily for gaming?  A friend of mine recommended the HD-558/598's over the AD700's, but I personally have never heard the Sennheiser's when they are used for gaming.  Would it be a worth while investment over my current AD-700X's at all?  They are similar in price, but I am just curious which headphone would have the best fidelity for gaming. 

I am afraid that I have never heard any of those headphones before.  If I had to choose, I would head over to Mad Lust Envy's thread about gaming headphones over in the Video Games section:
 
http://www.head-fi.org/t/534479/mad-lust-envys-headphone-gaming-guide-update-7-9-2014-ultrasone-hfi-15g-added
 
There are reviews on tons of headphones and how they perform for gaming there.  I see that the 598 is reviewed, but not the 558.  I am actually considering getting myself another headphone for gaming and plan to go through that thread to determine which one sounds best for me.  I am pretty sure that the author does most of his gaming on console, but as he is reviewing the headphones the information should translate well to PC gaming.

Don't get me wrong, I think the AD700X's I have are great for gaming, and with the rubber band mod they fit comfortably (I have a small head).  I just don't do any competitive gaming at all, mostly just single player, so I'm just asking around if the Sennheiser 558's would fit my needs better for a more immersive experience over the AD700X's.  Maybe other people would have an opinion on these two headphones simply for single player PC gaming as the primary purpose.....  

Yeah.  The thread I linked rates headphone on how it works competitively and how it works just for fun sererately.  I find the AD700 pretty fun just because of the soundstage, but I wouldn't mind having a can that people say is good for fun as well.