This track's low-frequency response peak is at about 37 Hz. It also has a few more low-frequency peaks, located at 45 Hz, 50 Hz, 55 Hz, and 64 Hz. These add quite a bit of extra low-frequency energy.
This track's low-frequency response peak is at about 41 Hz. The next peak is much lower in level and occurs at around 75 Hz.
I didn't actually look at the frequency analyser for those two. However, in my set-up, I can switch the sub in and out to compare with and without while a track is playing.
It should be noted that I have some room correction going on as well:
This will still be in place when I bypass the sub, which won't be correct. Ideally, I would need to re-measure and create a separate room correction profile for the speakers without the sub being active. This would likely increase the bass, without the sub, whereas the with-sub correction is cutting some peaks in the low end, which may not exist when just the speakers are playing.
Regardless of all that nonsense, sometimes I play a track that seems to have quite deep bass, but if I look at the analyser, there often isn't that much happening below around 40 - 50Hz:
Even less when you move away from electronic music, despite having a strong bass line:
The KH 150 looks to have a very capable mid/bass driver, so I imagine you could push it quite hard:
https://musicandmiscellany.com/2023/01/03/secrets-of-the-neumann-kh150/
The point of all my ramblings is, that I already had a subwoofer, so I optimised my set-up with it in place. However, I imagine that you could better optimise the response without using one, either with EQ, or speaker placement, or a combination, and it may be that the differences are smaller, such that the sub wouldn't be missed.