I have a couple of questions about subs, that I haven't been able to find answers to.
1. With all things being equal, what is the difference between a sealed and vented design?
This question comes to mind especially when looking at the Rythmik line of subs. They have vented and ported designs with the same 15" driver and amp. Many have claimed that sealed designs are better for music and more detailed. On the other hand, vented designs are said to have "group delay", where the bass signal has a slight delay, when it is played, which slightly muddy's things up. But, maybe a positive side effect (for say, explosions in a movie scene) is that the vented design may be perceived as louder at the same volume level, because of this slight delay. So if two subs are basically equal in frequency response, up until the subs hit their limit, will these things be apparent? Has there been any blind (double or single) testing done to show that "group delay" is actually something noticeable during different pieces of music or movie passages? Are there any other differences between sealed and vented subs, that show up in the listening experience.
2. What factor contributes to impact in a movie scene?
What I mean is that if you have two different subs level matched, playing within their limits in the room, with very similar flat frequency response curves (from say 20Hz to 80Hz), is one sub going to have more of an impact (thump you in the chest bass in action movies) than the other? Does a larger driver (or sum or areas of drivers, if there are two drivers) play a factor in this? Or, does sealed vs. vented design play a factor? Does the volume of the box, play a factor? Or does the amount of RMS wattage that of the amp play a factor? Or, is there anything else that plays a factor?
Quite frankly, in my experience, this design difference between the two types and what some perceive as being preferential for movies or music or visa versa, I believe is highly overblown. In my case, I have both types in my system(FOUR total) and either works for any type of sound coming through it equally well. With a multiple sub arrangement especially, as long as they are relatively close in power capabilities and frequency range along with being phased and balanced properly, it won't really matter what type of sub it might be. Room interaction will have a much greater affect on what you are hearing and getting it right than the design characteristics.