Rendering issue (SOLVED)

I tried to render a Reaper file today, and I'm having what seems to be a fairly common problem - the WAV output is waaay too bass heavy and sounds nothing like the Reaper session. The null test works just fine, so I think Reaper is rendering in a way that other programs don't like. Can someone help me out? Runnin 64-bit on Windows 8.1

^^ 6. If your player plays through the onboard sound chip, they often come with "enhancements" (=effects) which may be turned on. Check the control software for your sound chip.

1. Yeah, I've read a bit on here about other Reaper users having similar issues, but those threads haven't solved my problem. 2. Too bass heavy compared to my working mix in Reaper. However, if I import the mix back into Reaper it sounds fine. I've checked, and there's no EQ engaged on Windows Media Player. I did a test upload to Soundcloud as well, and that had the same problem. 3. I rendered to WAV, imported that into the original Reaper session and inverted the phase. Canceled out perfectly. 4. 44.1kHz 24-bit WAV 5. I used Windows Media Player, the Music program on Windows 8 and Soundcloud. All had the same problem. Importing it into Reaper or Adobe Audition fixed the problem, but rendering it led to the same issue. 6. How would I check my soundcard settings? I think you might be right but I'm not sure how to do that. EDIT: I think number 6 was it. I found an option for my audio device to disable all sound effects and enhancements. Checked that and it sounds fine, so thank you! I will post in here again if there are more problems.