Originally Posted by acribb
Honestly, how often do sub 16 hz frequencies occur in movies and music? Isn't it true that most low frequency output in movies and music occurs in the 16hz and above range?
Does the ultra low frequency extension we are discussing here really have true merit?
For what it's worth the couches and everything vibrate quite a lot on this suspended second floor. I honestly feel there is more tactile feedback than Adam's dual Cap 2400 ULF I demoed, but his subs are setup on concrete slab in a large open concept space. They are about 90% the tactile feel of Charles' 3x sealed SI 24" drivers which is around the same sized room as mine, but with a concrete slab.
And also, I have no issues at all packing these guys up and sending them back using the Shoulder Dolly I bought and another able body.
I'm just wondering if it's really warranted.
I think that the questions you are asking are very difficult for someone else to answer for you. A lot depends on your own perceptions and preferences. There is certainly some movie content below 16Hz (little, to none at all, for music), although there is far more content above that frequency, but what do we perceive that is different as we go lower? And, how much difference will there be in the two subs?
In what some people call the critical octave for HT movies, of 36Hz to 18Hz, the PB16's will go head-to-head with the Cap 2400ULF's. I would personally extend that "critical" range down into the low to middle-teens, and the PB16's will still keep-up down to about 14Hz. After that, the Cap 2400's pull ahead, and they have quite an advantage at 10Hz.
But, what does that actually mean in a room? To start with, I think it depends a lot on the size of the room. In your 2300^3 room, you will be getting significant room gain (pressure vessel gain) starting around 25Hz or so. By the time you get into the low-teens, say around 12 or 13Hz, you might be getting +12 to +16dB of bass boost. That depends somewhat on the room construction. That's a lot of low to mid-teens bass for anybody.
In my opinion, however, the numbers still don't really tell us very much. That is because our ability to hear tonality in sound only extends down to about 18Hz. According to listening tests I have read, no one hears tonal quality below 16Hz. That means that a 14Hz sound and an 18Hz sound are going to sound exactly the same to most of us. The 14Hz sound will have to be louder for us to hear it, but if we can
hear it, it still won't sound any lower in frequency than the 18Hz sound does.
We simply lose the ability to hear tonal quality at frequencies below about 18Hz, or below 16Hz, even for the hearing-gifted. For many of us, it might even be at 20Hz or higher. To be clear, I'm not saying that we may not be able to hear
an 18Hz, or 16Hz, or 14Hz tone, if we used a tone generator, at high enough volume levels. But, all the tones from about 20Hz down would sound exactly the same to most of us.
What can we hear/feel with even lower frequencies than 16Hz then? If 10-14Hz sounds are acoustically
indistinguishable from 16-18Hz sounds, what sensations are
different? Well for one thing, we can feel differences in tactile sensations at very low-frequencies. We can probably feel strong thudding/rumbling sensations down into about the low to mid-teens, and below that we may feel more physical pressure against our bodies, and more of a wobbling/disorienting sensation. Some people may really like the latter sensations more, and some people may like the vibrational sensations more. But, they probably occur at different frequencies for most of us.
The suspended wood floor and the overall room construction are factors too. Most suspended wood floors, in smaller rooms, seem to resonate sympathetically at about 20Hz or just a little lower. I believe at a little below 20Hz is where you are likely to be feeling the most floor, couch, etc. vibration that you described. It isn't likely that producing even more volume at 10Hz would increase your floor vibrations, for instance, because that is probably below the resonant frequency of your suspended wood floor, or of the sheetrock walls in your room.
My personal take on this issue of the comparison between the two subs has two components. First, in a larger room (say over about 3,000^3 or 4000^3), where room gain won't be as much of a factor, or on a concrete floor, where the suspended wood floor won't resonate at about 20Hz or a little lower, I would recommend a pair of Cap 2400ULF's over a pair of PB16's. In fact, I have done that quite a bit, for quite a few people!
That is the first component: room size and room construction. The second component is personal preference and/or curiosity. I'm not talking about preference for aesthetics or features. Those things are entirely personal and go without saying. I'm talking about self-identification as a serious basshead who is chasing the lowest frequencies at the highest volumes he can (Chucky, are you there?
). Or, I'm talking about someone who really does want to experience the wobbling sensations I described earlier, or someone who is genuinely curious about the whole <12-14Hz thing. Again, you should already be getting a lot
of room gain at 10-12Hz.
If you fit any of those descriptions, or have other reasons I have left out, then I agree with others who have advised you to buy a single Cap 2400ULF to test head-to-head with one of your PB16's. You should be able to tell a lot from a test like that, and you can always try the dual PB16's, at some point of that comparison test, if you just want to reassure yourself that the two PB16's really are enough. I think that nearly everyone gets to a point, finally, where enough really is enough. Others may continue to drag race, with their subs, as an important part of their hobby.
Personally if I were really
curious, I wouldn't send the two PB16's back until I was sure that the Cap 2400ULF's were a better answer for me. But, I don't think I would hesitate to potentially incur a return shipping cost for a single Cap 2400ULF, if I really wanted to compare the two different subs in my room.