We are absolutely right. There has been a deliberate and unethical attempt to mislead.
This is what they actually say.
REQUIRED BACKBOX (SOLD SEPARATELY) | bx-12sq (optional) |
It is only optional if you make your own back box! In the fine print they admit is can not work properly without the back box. To you and I, experienced in these matters can see it obviously can't.
The switch is to change the impedance for different amps. My guess is that this connects the drivers either in series or parallel. There is really nothing else it could do.
Honestly the presentation of this subwoofer is a disgrace and actually unethical.
Years ago, I did a couple of experiments with compressive woofers like that. They were not successful and I abandoned that line of research. I suspect the approach is valid, but that there were no really suitable drivers.
These drivers are made for the purpose. The specifications are totally inadequate and loaded with marketer speak. An FR is quoted, but there are no roll off limits. The FR graph is clearly not measured and drawn by a marketer and NOT an engineer. So the specs are meaningless.
So I have no idea whether this is a valid design or not. It is presented in a way that could be total fakery, but I just can't tell. I know one thing they would not have got a cent of my cash, without better and backed up information. This is especially important for an unusual design approach like this