I definitely care about price. I want to i
I did not state my question very well. I'm not concerned about price except in the fact that 2 10 inch speakers are going to cost more than 1 15 inch speaker of the same design.
A lot of people seem to be answering the question of which manufacturer makes the best lightest cabs.
I'm actually interested in which single cab of any given manufacturer (be it Peavey, Barefaced, Fender) Theoretically *should* move the most air without getting too big to be a pain to move without a cart or something.
I agree there's a lot of subjectivity here. The answer seems to be proportional to how young and spry the owner is. I guess it's a stupid question.
But there seems to be a consensus that between 32 and 35" is the ergonomic sweet spot for a proper bass scale length for an average adult human. In my mind there ought to be an ideal ergonomic shape of box for a human to move around. Obviously lighter is better and modern technology affords us to carry bigger boxes alone than we could before. But size itself gets to be cumbersome at some point. What configuration of speakers fit that box best?
Well, this may also seem to answer the question "which light cabinet is the best?" as well as your actually question, "where is the sweet spot between full blown power/air moved and smallest possible size?"
Since "cost" isn't a parameter in the balancing, I'd argue that the Barefaced BB2 is the sweet spot for a single cabinet than can do the most with the least effort of moving.
There are more powerful cabinets; such as the Barefaced Big Twin, or any number of others; but this BB2 single 12 cab can handle 800 W all day long, so it's plenty powerful;it moves the air of a typical 2x12. There are smaller cabinets; even within the Barefaced line-up, the Super Compact is only 23 pounds, and the One10 is just 15 pounds. The Aguilar's I have been using (SL-112) are 25 pounds. The Big Baby is 26 or 29 pounds depending on grill type. But, The One10 will handle 250, but not the big power of a BB2.
BB2 is an easy one-hand carry at 26-29 pounds, and is quite powerful and moves a lot of air. There are cabs that are lighter/more easy to transport, and there are cabs that can produce more total volume (by having 2 to 4 speakers on the cab). But, I doubt that there is a sweeter spot in ease-of-load vs power/sound than the Big Baby 2. The problem is that they are not cheap, if if you throw that into the calculus then maybe you get a different answer. As far as I know, you are not including that parameter.
EDIT: the "sweet spot" for cabinets will change with technology; the "sweet spot" of bass scale length, as you refer to, remains relatively unchanged becasue humans and human hands remain farily constant, unlike audio and psychoacoustic technology. Maybe some amazing new kind of bass might change that.
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