Might be worth getting REW, a UMIK-1 calibrated USB microphone, and doing a frequency sweep of your room.
That it took me *so* long to take this step and was a huge mistake. For $100 and a bit of mental effort (REW is free), you can see exactly what the frequency response of your speakers looks like. It is very possible that you are not hearing all of the bass the 2.7s are producing due to standing bass wave patterns in your room.
I spent so much time trying to get more bass out of my Coincident PREs with different amplifiers and the whole time it was just my room (and speaker/listening positioning) causing a 12db dropout at 40hz. There are no downsides to taking the time to do this in your room. If you're playing in the price range at which you're looking, it's a necessity. I was so stupid for not listening to the advice of others who said the same.
P.S. I had 2.4s and also wanted more bass... eventually added a Smartsub, but still wasn't totally satisfied. I suspect it was due to the above issue. I switched to high efficiency Coincident Super Eclipse IIIs. 28Hz vs. 35hz bottoms vs the Thiels, but a lot more bass in my room. Probably because of the side facing woofers changing the standing wave pattern...