I don't really understand what is meant by pressurizing the room. Can anyone please explain this physical process and its benefits?
I do, however, understand many of the terms and concepts involved related to achieving very good bass response in a given room.
A 20Hz deep bass tone sound wave is 56.5 ft. long. Since few people listen to music in a room that has a dimension that is that large, it means the 56.5 ft. sound wave of 20 Hz is emitted into the room and, once it hits a room boundary (floor, wall, ceiling) or other solid object in the room, it will reflect or bounce off these surfaces (at predictable angles) and it then continues on its new trajectory until it encounters another solid surface and reflects again. This process continues until the long sound wave runs out of energy.
How one perceives this long 20Hz sound wave depends on exactly where your head/ears are positioned within the room and whether the direct sound wave from the sub arrives at your ears first or if a reflection of the direct sound wave arrives first. To further complicate matters, the most likely scenario is that your ears will be detecting the direct sound waves and reflected (indirect) sound waves within milliseconds of each other which alters the bass frequency and detail perceived.
Also, as longer bass sound waves continue to bounce off of room boundaries they inevitably collide with one another. These collisions cause what are called 'room modes', which result in exaggerated, attenuated or even negated perceived bass at specific locations in the room. The more bass modes in a room, the poorer the perceived bass and vice versa.
Through their research and experiments the acoustical engineers mentioned on one of my previous posts on this thread, doctors Geddes and O'Toole, discovered that bass room modes decrease in direct proportion to the number of subs in a given room. The more subs in a given room, the fewer bass modes present.
Of course, they realized that there's a practical limit to the number of subs that individuals' significant others will find acceptable in a home environment.
Interestingly, however, they found that when 4 subs are deployed in a given room and located following a specific sequential procedure (which I can detail in another post), that the vast majority of the bass room modes are eliminated or considerably lessened in their affect. This is the basis for the AK Swarm bass system and the reason it consists of 4 subs.
Without any doubt, the Swarm bass system by a wide margin provides the best bass response in my room/system that I've ever used, much better than any of the numerous single and dual sub configurations I've ever used.
The improvements I notice are an effortless quality to the bass in which it will go as deep, dynamic and powerful as the source content calls for while also being very articulate and detailed in the bass that allows for clear recognition of the instruments being played and small variations of pitch and tempo. I believe both these qualities are unique to, and possible with, the Swarm due to its use of relatively smaller 10" sub woofer drivers and the fact there are 4 and not just 1 or 2 in the room.
I doubt it's a coincidence that none of my previous 1 and 2 sub bass configurations could match this high level of bass performance of the Swarm.
Tim