Now as for the OP’s comment. All I can say is I feel ya, but unfortunately
@shadyJ and others covered it well. Every time some new uber sub comes out I want to test it, but the idea of heaving a giant subwoofer around is not exciting.
I’ve thought a lot about this, what it would take to build a compact high-output subwoofer. There is no free lunch and such a product would be stupid expensive, but higher output and more compact subwoofers are feasible. As I noted earlier, linear drive based drivers would allow a lot more excursion and so the cone could be a smaller diameter. Imagine if a subwoofer driver worked a bit more like a piston on an engine or air pump. You wouldn’t want a slug of steel on the end of a connecting rod, but imagine a disc that silently moves more than 6” in and out at a rapid pace!
More realistically, using technology like Rockford Fosgate and others have developed to make very highe excursion and high BL drivers allows you to build smaller high output drivers. Stick a bunch of those in a small sealed box and add a ton of amplifier power and EQ and you get a lot of output. Add passive radiators and you might be able to score some efficiency down low too.
Enclosures don’t need to be heavy or dense to work well. They actually operate as a pressure vessel below the wall resonant frequency which means all that matters is stiffness to contain the sound. Low frequencies are this best contained by making a light stuff enclosure. That is why a sphere is best and a cylinder is next best. Unfortunately people think these are ugly and a bit expensive to reproduce. Sonotube is ok, it’s actually not ideal. Imagine a carbon fiber sandwhich material made into a tube, that would actually be lighter and stiffer.
@shadyJ has pointed out that such a high output and light subwoofer would probably launch itself around the room. My solution was to bolt it to the floor. Maximum tactile transmission. If you don’t want that, you could mount it to spring isolators. I think this is a great idea, not sure anyone else agrees. It would also be horrifically expensive.
I had a friend who wanted to go into the subwoofer business have me design it out and come up with a material list, parts vendors, and full pricing. Just to build the thing was around $20,000 in small quantities. Even if you are a JTR that becomes a $30,000 subwoofer to sell, and I question how reliable it would be. It would require a dedicated 240 line and use an expensive and exotic driver.
