XPost: alt.audio.pro.live-sound, rec.audio.pro   
   From: phil_a@tpg.com.au   
      
   "Peter Larsen"   
   >   
   > A sane way to design the 4 Ohm box would btw. be to stick with the same   
   > midrange and top components as in the 8 Ohm box.   
      
   ** Long as similar woofers and compression drivers are available in 4 and 8   
   ohms, that is the easiest way to do it.   
      
     ( Note that the 8 ohm version uses a 16 ohm compression driver. )   
      
      
   > But there sees to be no valid technical reason to make a 4 Ohm box for   
   > those that can't afford large amplifiers if it ends up in toy class   
   > efficiency so that they get more sound from the same amp by getting the 8   
   > Ohm version.   
      
   ** Obviously true.   
      
   Another way to convert any box from 8 to 4 ohms is to simply install a   
   matching transformer at the input,  ie an auto-transformer that gives a 41%   
   step up in voltage.   
      
   A toroidal cored type would make it quite small and inexpensive too.   
      
   BTW   
      
   The size of the magnet does not change with rated impedance -  4, 8 and 16   
   ohms versions have identical magnet structures.   
      
   Speakers have been made with impedances from 0.5 ohms ( eg Bose) up to   
   hundreds of ohms and the only thing that changes in the gauge of the wire   
   wound on the voice coil.   
      
      
   ....  Phil   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)