Bass Traps

Couple of things.  One, taming a very live room by controlling mid and treble reflections makes the bass stand out more prominently, so this could just be mid/treble absorption.  Another thing that happens is that valleys are reduced... if you had set the bass level based on the "average" bass level then that just came up a great deal.

Usually we find the opposite is true though, usually some exaggerated room mode has so much output we have to reduce the subwoofer level, and then find when we've clipped those peaks we can now bring the sub level up and it sounds much more full and complete.

“Anyone know why I have more bass with the traps than without?”

You’re probably not getting more bass, you’re just getting better, cleaner bass. Without bass traps, low-frequency waves bounce around the room and interact with each other, often canceling out at certain points (called nulls). Bass traps absorb some of those reflections, which reduces cancellation, meaning you hear more of the bass that’s actually there. 

Bass traps help flatten peaks and nulls in the bass range. So while the biggest peaks may be reduced slightly, the valleys are raised giving the perception of more consistent and solid bass.  

Enjoy your new found musical bliss!

Get those traps into the corners. As others have pointed out, you have shifted the response of the room now. It would help you to run REW and dial in your room using the graphical results.

I made a run once with REW moving the traps inside the front speakers (out of the corners) and it was as if I had not trapped at all. Moving them back into the corners restored the improved room response.

wait are you doing this blind without measurements? @mjjw 

This video is timely - Acoustic Treatment: The Strategy for Small Studios

Yes it is for studios but the general comments are very much what you need to get familiar with. But for the love of all things good, get a calibrated mic. This should do - miniDSP UMIK-2 - USB Reference Measurement Microphone

Also, please talk to GIK. Room treatment is a science and should be treated so.

Acoustic Fields,

https://m.youtube.com/watch?v=QwgrJVLniLc