Wait a minute...
@KEW You like ported subs now? I thought you only liked sealed subs?
I'm still of the same essential opinion, but I believe my understanding of the "why" has evolved.
Here are my thoughts on the matter:
1) I think a
simple sealed sub has a better starting FR for music in a typical room. My belief is, after room gain, you get close to a flat FR that only requires modest EQ. More importantly, you do not run much chance of bass being too strong which can totally ruin the overall SQ. This is, IMHO, the least expensive way to get good bass for music in a typical room. I see your sealed Rythmiks as a fantastic sub in your bedroom system with the Ventos!
2) I think a sealed sub
w/DSP which has been EQ'ed to be flat in an anechoic chamber can be as bad as a ported sub. This is based on my experience with dual JL Audio e112's and a SVS SB-12plus (although it had a PEQ which could be used to tame the low bass). In principal, I don't like the idea of adding DSP then having to EQ it the opposite direction to get flat response in room.
3) Simple
ported subs are much easier tuned to obtain anechoic flat FR. We learned to look for a flat anechoic FR for speakers because at most frequencies room gain is not an issue. However, we know room gain dramatically effects low frequencies in most rooms. Accordingly, I question the wisdom of seeking flat anechoic FR. The lowest level SVS ported subs are good examples of subs that I would absolutely avoid, because they do not offer means to tune the sub to your room. The Dayton SUB1200 is an exception to this rule as they did not use the port to try to get the deepest response they could. It rolls off more close to a typical sealed sub.
Note: While I question the wisdom of using anechoic flat FR as a measure of how good the FR of a sub is, I do acknowledge for a repeatable measure that will yield similar result measured at different facilities, the anechoic chamber and measurement methods to imitate it are useful.
4) I believe ported subs such as the Outlaw X13 and Hsu models (between two port plugs and EQ options) offer a wide enough array of tuning options to be tuned well in room. I want to test this theory out soon, but looking at the anechoic frequency options ShadyJ revealed in his review of the X13, it does not look difficult to mimic the FR of the PSA SX-15se which is the only sub that I have experienced that is listed in databass (my Rythmik E15HP's being the other option that I find easy to integrate in-room for music.
I haven't looked into the abilities of the SVS DSP systems, but suspect they have this covered as well!
5) I feel that for HT, lots of very deep bass can be fun, so can understand that attraction to ported sub style bass. And also if you want "the club sound" or dubstep it is appropriate, but not for more traditional (and especially acoustic) music. I am 98% music, 2% movies.
6) I wonder if an additional attraction of "near field" subs is by moving them into the center of the room you are typically significantly reducing room gain effects.
7) Josh Ricci has stated that the measured characteristic of subs which we most commonly regard as "tight and musical" is most closely tied to having a FR which puts more emphasis on higher frequencies and less on low frequencies. That info seems consistent with my experience and thoughts on room gain.
In conclusion, for music, a simple sealed sub seems a less expensive path to a good in-room FR. Generally the cost of the extra cabinet (including shipping costs) exceed the cost of the extra wattage of a sealed sub. For HT, I can appreciate more deep bass and the giddy feeling when things that "shouldn't" start shaking. With my sealed subs, I run them ~6dB hotter (using the Denon input dependent setup feature) for DVD's than CD's.
