You can do some Googling if you want to understand the benefits of bi-amping or tri-amping audio signals. What I'll observe here is that you're right about this much:
 

ty_ger07
The design of the 2.1, 5.1, and 7.1 recording and playblack standards should ensure that what is output from the card is correct.

And in order for the NuAudio card to do what is correct, it needs to put all the content below a crossover frequency on the CSub channel. That's what it means to support a subwoofer. That's why audio receivers, professional audio equipment, and literally every other piece of (pro-)audio gear I've had supports the very basic notion of a crossover frequency. Otherwise, your subwoofer is doing virtually nothing useful, and all your other drivers that aren't intended to produce low-frequency content are being handed low-frequency content that they're not designed to produce and don't produce well at all.
 
You clearly don't understand the details of bi-amping/tri-amping audio or how a subwoofer is intended to work.

No one produces audio with low frequency ("subwoofer") audio on only one left or right, front or back audio channel. Everyone produces bass content as monotone which occupies the "center" channel. Therefore, there is no crossover needed, unless you feel that your speakers are not working properly, or you feel that the record producer knows less than you do.

Like I said, add filters if you insist. You can easily do it; no software needed. Plug into all of the audio outputs, perform whatever crossover you want, and then connect your speakers to that. But don't blame EVGA for failing to do some goofy audiophile niche thing. If EVGA wanted to chase the audiophile niche-thing rabbit hole, they would find no end.

No one who is respectable, produces stereophonic bass. Why? Because the human ear is not good at localizing low frequencies. It's monotone. It's on the center channel. It doesn't need to be directed from the left channel or the right channel to the center channel. It is already in the center channel.

The bass remaining on the individual left, right, front, and back channels is the bass content (likely mid-range content actually) that the record producer or artist wanted to be there. They had full control when they recorded it and released it. All the bass on the center channel is what they wanted. Not enough? Add an amplifier to your sub. Center channel bass frequency too high for your sub? Add a low-pass filter before your sub because the sub's manufacturer apparently forgot to.  And if your individual speakers can't handle the mid-range content due to some defect or design issue, add a high-pass filter to them.

When you make this request, you are making 2 statements:
1) My favorite artist and/or producer is dumber than me.
2) My speakers don't perform to my expectations, and I think it is my sound card's job to fix that.

Both seem a little absurd to me.

You're right that "No one produces audio with low frequency ("subwoofer") audio on only one left or right, front or back audio channel." You're also right in saying "No one who is respectable, produces stereophonic bass." But you're then completely wrong in where you go from there. The entire point of a subwoofer is to reproduce the low-level content. Every 5.1/7.1 computer audio card in existence supports a subwoofer by letting it share an output with the center channel, their combination typically referred to as "CSub" as I've been using.
 
Now let me explain tediously why you're dead wrong in your conclusions, since you seem uninterested in actually learning about bi-amped/tri-amped audio using a 5.1 setup as an example. Without a dedicated crossover at the driver level, all the low frequency content of the existing front right/left channels goes to the front right/left speakers. If there's any rear audio at all (depends on source, after all, and what other features your audio card allows), then its low frequency content goes to the rear right/left speakers. If there's any center audio at all (again depends on source and such), then it goes to the CSub channel.
 
That's it. And what audio does one find in the center channel of any 5.1/7.1 source? In most cases, nothing more than dialogue. And since dialogue doesn't really have stuff in the frequency range your subwoofer is designed to operate (typically <80 Hz.), the most you'll get is some plosive thumps. In short, as I have said before, your subwoofer is a largely useless lump without a proper crossover. If EVGA does the smart thing however, like literally EVERY other bit of (pro)sumer gear I've owned, then all the low-frequency content below the threshold would be properly separated from all the other channels and piped to the CSub channel where it belongs.
 
This is the whole point of bi-amped audio: using a separate amplifier for the low-end to free up all the other drivers to work more efficiently.

I'm with Phileosophos.  Had this feature on my Asus and it looks like Creative's software has this feature too.  

Bumping this because bass management is common (it's not niche) on sound cards but absent from the NuAudio 7.1. Got a laugh because I found when researching this for the NuAudio 7.1; I'm guessing some EVGA motherboards have the onboard Sound Blaster option. Even found tips for on a Realtek chipset. For such a nice card, it really needs some bass management options (ability to select full-range speakers, filter frequencies to sub channel).
 
I understand ignoring bass management for stereo use (NuAudio sounds awesome just playing music), but for surround sound content passing through analog outputs on a sound card, bass management is necessary because you can't assume that everyone is running 5-7+ large full-range speakers all around and you can't assume that the amplifier is performing bass management. A Logitech 5.1 computer speaker set might perform its own bass management for the sake of its tiny speakers, but those using 7.1 out are probably going through an AVR and my Denon and Onkyo AVRs don't perform bass management on the multichannel analog input (connected to sound card), so I assume that behavior might be common on AVRs with multichannel analog inputs; the AVR simply acts as an amplifier for the connected speakers at that point and depends on the source device (ex: DVD player, sound card) to perform bass management. For more information on why bass management is important, google 'home theater bass management', if there's still a lack of understanding or you just don't care, then maybe you're not the target demographic for a 7.1 sound card.
 
Yes, for music and movies, you can manage bass from the playback application (Foobar2000 has plugins for this, Media Player Classic variants probably have settings or plugins), but bass management for games requires support from the device drivers. Games don't often have movie-quality mixing, some seem to throw everything at the speakers and nothing at the sub, which makes you dependent on bass management to route those low frequencies to the sub to get the full effect. An AVR can certainly correct for that behavior, but based on my experience, that would require the sound card to have an HDMI interface on it. ¬_¬

Again, it is VERY easy to add a low pass or high pass filter before and/or after your audio receiver. I suggest that you do. Low pass and high pass filters are VERY VERY simple and cheap. You can even make one yourself. I was making my own low pass and high pass filters while I was only a 7th-grader.

Proper speakers have had their dynamic range characterized by their manufacturer and have the requisite low pass or high pass filters built in. If yours is missing, there is no reason why you should spend weeks or months complaining about it here instead of just fixing the problem yourself.

ty_ger07
Again, it is VERY easy to add a low pass or high pass filter before and/or after your audio receiver. I suggest that you do. Low pass and high pass filters are VERY VERY simple and cheap. You can even make one yourself. I was making my own low pass and high pass filters while I was only a 7th-grader.

Proper speakers have had their dynamic range characterized by their manufacturer and have the requisite low pass or high pass filters built in. If yours is missing, there is no reason why you should spend weeks or months complaining about it here instead of just fixing the problem yourself.

Based on what you keep repeating here, you've demonstrated that you don't understand the request in the initial post and you clearly don't understand bass management in the context of a surround sound home theater system. I'm sure many of us understand that speakers are built to cut frequencies they're not capable of handling, that's not what this is about. Do you even have a sound card?

Bumping is not allowed on this forum.
 
Based on what you've said, you've demonstrated that you don't understand that "bass management" is an act of using low pass and high pass filters, and have demonstrated that you don't realize that configuring your analog audio inputs and/or outputs is a trivial task.

Phileosophos
And what audio does one find in the center channel of any 5.1/7.1 source? In most cases, nothing more than dialogue. And since dialogue doesn't really have stuff in the frequency range your subwoofer is designed to operate (typically <80 Hz.), the most you'll get is some plosive thumps.

 
If it is dialog that you are after, add more than just a subwoofer to the center channel.  Wire in a subwoofer in line with a low pass filter (if it doesn't already have one incorporated) AND wire in a mid-range speaker in line with a high pass filter (if it doesn't already have one incorporated) in parallel with the subwoofer.

ty_ger07
Bumping is not allowed on this forum.
 
Based on what you said, you've demonstrated that you don't understand that "bass management" is an act of low pass and high pass filters, and that configuring your analog audio inputs and/or outputs is a trivial task.

Phileosophos
And what audio does one find in the center channel of any 5.1/7.1 source? In most cases, nothing more than dialogue. And since dialogue doesn't really have stuff in the frequency range your subwoofer is designed to operate (typically <80 Hz.), the most you'll get is some plosive thumps.

 
If it is dialog that you are after, add more than just a subwoofer to the center channel.  Wire in a subwoofer in line with a low pass filter (if it doesn't already have one incorporated) AND wire in a mid-range speaker in line with a high pass filter (if it doesn't already have one incorporated) in parallel.

You're avoiding the question: Do you have a sound card? Is this post relevant to you?

satsun

ty_ger07
Bumping is not allowed on this forum.
 
Based on what you said, you've demonstrated that you don't understand that "bass management" is an act of low pass and high pass filters, and that configuring your analog audio inputs and/or outputs is a trivial task.

Phileosophos
And what audio does one find in the center channel of any 5.1/7.1 source? In most cases, nothing more than dialogue. And since dialogue doesn't really have stuff in the frequency range your subwoofer is designed to operate (typically <80 Hz.), the most you'll get is some plosive thumps.

 
If it is dialog that you are after, add more than just a subwoofer to the center channel.  Wire in a subwoofer in line with a low pass filter (if it doesn't already have one incorporated) AND wire in a mid-range speaker in line with a high pass filter (if it doesn't already have one incorporated) in parallel.

You're avoiding the question: Do you have a sound card? Is this post relevant to you?

No, I don't.  There are a lot of things I choose not to have.  That has zero impact on my knowledge and understanding.  I read a lot and I experiment a lot.
 
What is your point?
 
 
 
 
Have you considered setting up YOUR audio equipment to work the way that YOU WANT it to work?  So, do it!