Shouldn't it be crisper/cleaner/more vibrant?

In my system I have the Klipsch La Scala (AK5) for the past 6 years. I did not feel like I needed more bass or extension on the lower end. As the final part of my audio room, a few months ago, added a pair of REL S 212s. I did this not for the speakers, but for the room itself.  Wow, really transformed my audio room and listening experience. The room has more depth, wider, deeper, & bigger sound stage on all tracts and whichever source was played. Even tracts with very little low end (female voices, piano, acoustic guitar) there is so much more nuance. Felt more like a live performance & I was seating in the sweet spot of the amphitheater... the whole room was transformed. To note – I did have a chance to listen to the newer AK6 version recently…I prefer mine, the AK5s…sometimes newer is not better.

I know no one ever wants to talk cables…. But just putting my 2 cents out there. If you’re interested in investing in new speaker cables. Two of my friends have been very happy with Audio Envy’s speaker cables. Been a while since I’ve changed mine out but I’m actually considering it after listening to both of their systems.

The problem is probably your room, speaker setup, or acoustics.

OP "a bit brighter and cleaner." than what? What did they replace?

@patrickalston Of course the bass comes from the recording BUT speakers need to have the capability to reproduce the deep bass! My Legacies dip down to 18hz -2dB. Most of the Klipsch speakers can't do anything like that especially their heritage line that use folded horns.