I am relatively new to all this, but that hasn't stopped me from thinking. My wife of 30 years just sighs and finds a book to read when I tell her I have been thinking again.
My observation is that over the last 20 years, driver size for subwoofers has increased considerably. 12 inches used to be a big driver, and today it is a starter. But over the same time, enclosure size seems static or even shrinking. As I understand the first law of thermodynamics, matter can be neither created or destroyed, so where is all that air coming from? My suspicion is nowhere, and that more power is being used to compensate.
So I decided to make a subwoofer that had the recommended or required space. And I decided to go big with it. The WAF factor in my house is pretty lax because the home theater is in the basement, which is my space. But I still wanted to avoid creating a monstrosity. Science generally says that round or curved objects are perceived to be smaller that square or rectangular objects of the same volume. So I decided to round. And to really test the idea, I decided to go with 2 24-inch SI-24 Mk II. In a ported enclosure, they require 16-20 cubic feet each, so 2 in an opposed system are 32-40.
In a box that would be a 2x4 footprint 5 feet tall. Even in my house, that is going to raise some eyebrows. But a 3 foot wide column six feet high is just a large decorative feature, especially if it is covered with a nice finished veneer. Putting two drivers in it is going to require one at the top and one at the bottom. Sonotubes are made of cardboard, and No matter how think it is, I still am not a fan of putting a 115 pound subwoofer on top of it. I also am just morally opposed to the idea of a cardboard subwoofer in the first place.
An easy alternative exists. Curved plywood is a readily available commodity, and it is easy to get half circles in most typical diameters. I can create my 3x6 tube of 5/8 inch plywood for under $500. That is still a lot of money compared to a sonotube, but worth the cost as I see it.
My questions for the group are whether this makes sense and if anyone else has gone down this path? The HS-24 are rated at 2000 watts, and a SP1-4000-HT amplifier from speakerpower.net could cost $999 and provide 2000W channels. Makes for an expensive sub, but seemingly an impressive one.
My primary purpose here is to experiment and learn, not to make the best subwoofer I can. I can easily reuse the parts for that later. Any thoughts would be welcome.