This is an interesting analogy with regards to subs, but I think its only half right. Once a sub get to a very good qualitative level, then multiples using these mid-level subs can quickly exceed the performance of a higher end sub, especially in qualitative indicators. By far, the chief metric that determines sound quality in bass is frequency response. Two subs can get a much flatter response in room than a single sub. So, qualitatively speaking, you could get a better fundamental sound from two PB-1000s than you could with a single SB16-Ultra. Qualitatively speaking, the Ultra would still have an advantage of deeper extension, but the more neutral response of dual subs would be a far more audible advantage. The SB16 would still have an advantage in dynamic range, but that can be made up for by just adding more PB-1000s, which could also further flatten out the response which further increases their sound quality advantage. A properly set-up quad PB-1000 system is going to sound much better than a single SB16-Ultra system yet costs the same.