I think that my friend Ken is much too modest. His thoughts are never ignorant, in my opinion.
But, this subject interests me, so I decided to look at the Data-Bass results for the PB13, compared to the SB13. The 4000 Ultra and 16 Ultra models will have essentially identical results to the 13 Ultras below ~16Hz. At 12.5Hz, the SB13 and the PB13 (in 15Hz mode) have almost exactly the same max SPL. Then, between 12.5Hz and 10Hz, the PB13 rolls-off by about 5db more than the SB13 does. So, the only difference in low-frequency extension between these two subs is literally at ~10Hz.
There are two aspects to consider when evaluating how meaningful that 5db difference at 10Hz is. First, how much 10Hz content is there, and second how do we perceive 10Hz content? As for the first, about the only isolated 10Hz content I know of is the 10Hz sine wave in the intro to EOT
, and the PB4000's should knock that out of the park in a small room.
Based on everything I have read and experienced, we don't usually hear
frequencies below ~16Hz, except with headphones and isolated test tones. Instead, we hear some of the low-fundamentals of notes and their harmonics (overtones), and that is particularly the case with complex sounds rather than sine waves. Most of what we perceive below ~20Hz, and certainly below 16Hz, is probably tactile sensations, with some low-fundamentals and upper harmonics.
The consensus on most of the bass threads where I have seen this discussed, is that significant SPL into the mid to low teens is the most important goal. I have heard a number of people who have output into single digits say that having it is more a matter of bragging rights than it is of creating a substantive improvement in their HT experience. I am not offering that as a definitive statement, just noting it for what it's worth. This is a YMMV issue.
People who enjoy having sealed subwoofers, and who get sufficient bass sounds and sensations, are probably lucky in that their subs are typically much smaller than the equivalent ported versions. But, people who crave more max output at low-frequencies, and more corresponding tactile response than sealed subs can produce, should not actually be giving up much if any low-bass, compared to their sealed counterparts, where the PB4000's and PB16's are concerned. And, they will get much
more bass down to 16Hz, and below, before simply equaling the sealed subs at ~12Hz.
Especially in a small room, where the very low-frequencies will be strongly amplified by room gain, if someone is daring enough to go with ported subs, I don't think that he will be missing out on anything at all, except perhaps some plaster from the walls.
Just kidding (I think) about that part.