I also feel the bass is missing some Oomph. I only have two speakers, the X5 and Harbeth 40.1. The 40.1 has significantly more oomph. It has a 11.8” woofer, so, comparable to the 12” in X5. What I don’t understand is that, I got more oomph driving the 40.1 with a 75W amp. The X5 has a 250W Hypex Fusion NCore plate amp and I tune it all the way up. I only listen to Jazz, so, for the bass, I am referring to the double bass and drums. But I have to be clear, the bass for the X5 is good, much better than other speakers I previously owned. I use a Luxkit A3300 preamp where I can tune the bass. If I tune the bass up by 1 click, I got something similar to the 40.1, so, i just wish to have a bit more oomph, not a lot. I am curious, is that we can adjust the amp? I expect more bass with a 250w for one 12” driver. I think the current max setting should be around 70%, so, there is more room to increase the bass.