I've also been told (perhaps erroneously) that a sealed design is preferable.
While people do say many things, many formed by their experiences that may or may not be definitive, I'd take care not to deal in any absolutes. At times, people's opinions are formed by experiences with compromised designs that may have other flaws. At other times, their opinions are based on theoretical advantages that may not be audible - and I'm as guilty of that as another person might be.
Different designs do have their advantages and disadvantages, but the audibility or effect of these advantages is dubious at best when set up properly in a person's room. Some complain about the time delay that a port introduces to the mix - yet those same people might be using a vented main, a crossover, another crossover, and a room. A sealed sub can have its own set of issues that largely go ignored - in fact sometimes people enjoy the coloration that a sealed enclosure is capable of adding.
The number one rule is to never believe anything anyone else says because you'll just as soon find another person who doesn't have the same experience. You'll find people who supposedly say they can instantly hear the effects of preamps, cables, cd players, DACs, 2nd order harmonics, and sub vents, and you'll find people who, try as they might, only hear the music reproduction by the speakers and their interaction with the room, within the amp's limits.
End of the day, both of the above parties tend to be one thing - hobbyists like you and I, and likewise they've not done the controlled testing to make definitive statements, although we can learn from either party, we need to take everything with a grain of salt. Without controls in place, there's too many variables at play.
For example, let's take the concept "if your mains have vents, shove some foam in there to make them better; isn't sealed great"?
Except a few problems i can instantly name with that:
- you probably went from a specific vent ::tuning:: to an overdamped sealed ::tuning:: - and most of us agree that overdamped tunings sound different from underdamped or adequately damped.
- your frequency response changed wildly
- there may have been a room issue your vent was merely revealing, that the sealed is not exciting.
- you were told sealed sounds better, so you're listening with the intent of hearing sealed sound better
- the driver may have been unloading below the vent tuning at high SPLs, and that's no longer happening.
- the vented speaker, may actually have been a poor design with internal standing waves that were leaking through the vent
At the end of the day, there are people who are quick to reject controlled all the perceptual research (IE Toole states people couldn't hear a difference between vents and sealed when properly set up). It can be wrong, because there's a human element involved in such research, but it can't be so wrong as to suggest that the differences if they do in fact exist within the thresholds of human audibility, are instantly recognizable.
My opinion? A single sealed 12 is rarely "preferable" in my opinion.
For starters, a single sub solution is never going to do a quality music setup justice without heavy EQ for a single listening spot. It's the nature of a sub's integration with the room. So we need to establish the need for two subs minimum, preferably three or four.
A sealed 12 will also prefer a :lot: of cone motion to reproduce the deep stuff (you mentioned that you'd like full range performance that's versatile between rooms). That's only going to lead to distortion and you'll quickly find the sub hitting its limits too.
If you go with a vented sub, you do reduce the cone's motion down to its vent tuning (at the cost of increased motion below that tuning of course, which needs to be electrically rectified) so that you can optimize the driver motion. Else you really need OVERBUILT drivers, which in turn raise cost and probably need more expensive amplication.
Definitely weigh, not reject, a lot of options, and remember that the room is on orders of magnitude the most likely culprit for reduced fidelity, if the sub is a decent one. My suggestion would be to give a pair of SVS PB12+ a strong look, costly as they might be. Whatever you get, give two or three STRONG consideration.
