Originally Posted by cannga
You took the words right out of my mouth as usual. I was about to post the figures but you have a quicker trigger finger.
To best of my knowledge, ultra low bass versus upper bass is a design trade-off
. This is why whenever I see a subwoofer with ultra low bass capability, the first place I look is in the upper bass. How much did designer sacrifice upper bass.
That's the objective number, but subjectively how would the trade-off sound differently? Only Jeff knows, and he ain't talking so far.
I think it's a really interesting question. I have my own general theory, which I believe makes some sense. But, even with my generalization, a lot would depend on room size and the crossovers someone is using. I think if someone is using crossovers no higher than ~80Hz, that subwoofers which produce more low-bass SPL might be especially valuable. That would particularly be the case if the room size were ~2500^3 or more. Smaller rooms might reinforce the frequencies below about 30Hz enough that it would make less difference to have strong low-bass. And, of course, a lot would still depend on pure preference for low-bass versus mid-bass.
My thinking has always been that if you want to hear frequencies below 30Hz, in equilibrium with mid-bass frequencies, you need subwoofers that accentuate those very low-frequencies. That is because, if you boost your subwoofer loudly enough to get strong low-bass sounds and tactile sensations, you will also be boosting the mid-bass frequencies at the same time. And, they were easier to hear in the first place.
So, the more discrepancy there is between the mid-bass and the low-bass, in the subwoofer's fundamental frequency response, the harder it will be to get the ULF we may want. (Unless we can do a true house curve with something such as a miniDSP--boosting the low bass at the expense of the mid-bass. The LFA isn't really a trade-off between low-bass and mid-bass, although it can certainly also help in that regard.)
This is why I have personally leaned toward subwoofers which emphasize low-bass frequencies more than mid-bass frequencies. But, I check all of the boxes for that interest. I have a large room; I am on concrete (which doesn't provide much tactile ULF); I use 80Hz or lower crossovers; and my room actually enhances mid-bass frequencies. I can see someone in a small room, with a lot of room gain and higher crossovers, preferring the exact opposite of what I want. That person might do much better with a subwoofer which deliberately emphasizes mid-bass frequencies more than low-bass ones. Some ported subs do that, and that is also why sealed subs can be so effective in small rooms.
I do think it is one of those YMMV questions.