There is still a very healthy market of bass players who are dedicated 4 string players, have no interest in playing a five AND have no interest in de-tuning. That means that there is a large number of amp/cab buyers who have no need for any capability below 40 or 41 hz, ever. if a modern cabinet maker was able to offer a cabinet specifically to this market, would he be able to make significant design/construction decisions that would optimize the performance and efficiency of the cab in the 40hz and up range at the expense of substantially degraded performance below 40hz? would ignoring the range below 40hz offer any significant savings or performance increase? or is the difference between 40hz and say 30hz not significant in terms of cost or performance for cab designer/builders?