This is a post to describe how to setup a Sound Blaster Audigy Fx V2 to use a subwoofer that only has one RCA input for the LFE signal, using a Windows 10 PC. I am posting this in hopes to help others, but I may, or may not, respond to requests or comments asking for help, depending on time. This is only a guide for those stumped by lack of info from the mfg. on this sound card. I appreciate updates pointing out any errors.
This information is not readily available online or in the official instructions, so I decided to document it for others. To start with, here is a picture of the sound card ports, we are going to be using the C/SUB port.
Once you have the sound card installed in the PCI-e slot, install the Creative App software from the website https://support.creative.com/Products/ProductDetails.aspx?catID=1&catName=Sound%20Blaster&subCatID=1137&prodID=23784&prodName=Sound%20Blaster%20Audigy%20Fx%20V2
Reboot the computer and open the software, and download and install the latest driver for your operating system. Then reboot the PC again.
Now we will need a cable to go from the sound card to the subwoofer. This is a major point where the mfg. does not give guidance. We need a regular 1/8 (3.5mm) stereo plug to RCA splitter cable, like this: not a mono cable. The plug that goes into the sound card must have the Tip, Ring, and Sleeve…not just Tip, and Sleeve.
These are common splitter cables easily available online or at most local big box stores. I prefer Hosa cables, like this one: https://www.amazon.com/gp/product/B000068O33
Plug the cable into the sound card using the C/SUB port, and then plug the RED end of the RCA into the subwoofer RCA jack. They do not tell you this, but the subwoofer sound comes from the red jack, and the center channel comes from the other jack, which is normally white, but sometimes black or grey.
Then, go into your Windows settings for the sound card, type Sound Settings in the Window search. Make sure the correct sound card is selected for output device, then click on Sound Control Panel.
Click the Sound Blaster Audigy card, then click configure:
Click 5.1 Surround, then Next
Make sure only the Subwoofer is checked, then click next
Make sure full range speakers is clear, no check boxes on this page, if you select full range speakers, it will prevent bass signal from being sent to the subwoofer…. click next, then click Finish
Now, open the Creative App software: Click Playback, then click the 3 dots next to Speakers (Line Out). Your setup should show the 2 speakers, with a subwoofer:
Now, make sure Full Range Speakers is not checked, Choose 2.1 Surround configuration, unless you are using 4.1, or 5.1 surround. Make sure to check Bass redirection, and Subwoofer Gain, all as shown here:
Also set the crossover somewhere between 40-80Hz, you can play with that later. I suggest 50-60Hz.
Click Done, and now you need to adjust the levels on your subwoofer. If your sub has a crossover knob, turn that all the way up, because the sound card is handling the crossover….and set your volume level. Your system should be working now. Close the speaker configuration page, and now test the sub by clicking the subwoofer icon.