Lower Crossover, Critical to Hi-Fi Reproduction

    It is not practical to ask a 1“ dome tweeter to drive from 20KHz down to 800Hz, no such product on the market today; even it does, the FMD must be very high due to its moving diaphragm is too small.  On the other hand, a woofer also has great difficulty to properly respond from 40Hz up to the 4KHz range. These limitations derive not only from a cone mass which is too heavy, but also the necessity to factor in cone break-up distortion.  Based on Fc=Cc/2pa, a 5” driver is supposed to carry frequencies no higher than 1600Hz; and this Fc shall further be cut-down by larger sized woofers.

         It should be noted that based on acoustic speed in 2100ft/sec, typical of paper cone drivers, other cone material such as aluminum or Kevlar having higher conducting speeds, a higher Fc may be expected to be achieved; however, utilizing a highly conductive cone does not help to resolve FMD concerns, and the FMD pollution becomes even more severe for wider bandwidth as well.  

    As M&D essentail requirement, in order to keep the 800Hz-4KHz mid-range band’s integrity which must be covered by only one driver; the audio crossover point often chosen today by most 2-way speaker manufacturers (typically in between 2KHz to 3.5KHz), is simply too high for true Hi-Fi reproduction! 

        Changing from a 2-way to a 3-way system is the most convenient solution to resolve FMD concerns.  However in this case it is not appropriate for small bookshelf speakers, whether reviewed from no matter from a Hi-Fi or an economic point-of-view.  

         “Simplicity is the best” has always been our motto. We may be able to solve the crossover network problems by Computer Aided Design (CAD) but there is no way to “perfectly match” two drivers due to different cone shapes, diaphragm materials, transit response, dispersion characteristics, and spacing interference, plus the complicated interactions when all these factors are put together.  3-way systems often cause even more problems than they solve, not to mention the unnecessary costs in system complexity.

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