ff99cff2   
   From: digilyd@hotmail.com   
      
   ChrisCoaster wrote:   
      
   > The two key differences are:   
      
   > 1. All drivers(2 in the bookshelf and 3 for the floor-standing) would   
   > be in the same plane.  That is, the mid and hf elements would be set   
   > back so as to be "in lne" with the resting position of the woofer.   
   > This is not new, and many mfgs have done it for 20 years or more.   
      
   And lo and behold, it actually is a poorer design than having them all   
   integrated in the same flat surface because of the additional diffraction   
   edges and the strange multivariable baffle diffraction steps you end up   
   with.   
      
   > 2.(the big one!) - The woofer - and the midrange in the case of the   
   > floor-standing, would have a range of travel unprecedented for their   
   > size.   
      
   Dick said a lot of what can be said. However look at the "known good"   
   loudspeakers, those are in my experience characterized by minimizing the   
   excursion via a large effient area. This because it is easier to get a   
   suspension quasi linear within a small range than within a large range.   
      
   > I'm proposing a 6" woofer and 1"dome tweeter for the bookshelf, and a   
   > 7"woofer, 3"mid, and same 1"dome tweeter for the floor model.   
      
   Bass unit size in itself needs to be seen in the context of box size,   
   intended bandwidth and obtainable efficiency.   
      
   > I'm talking about both woofers having at least a 1" high-profile   
   > butyl- rubber surround that would allow visible movement even when   
   > driven mildly.   
      
   It is all about displacement volume.   
      
   > The midrange might also be visibly moved, especially   
   > on tracks with strong transient drums(think early-to-mid era Genesis   
   > or just about anything from LZ).   
      
   Depends on what you call midrange.   
      
   > Of course an area in which I have no expertise would have to be   
   > advanced - and that is dampening.  For a speaker like this the cones   
   > might end up ringing like a bell!   
      
   Your vision of a loudspeaker cone is too simple, rigid cones are generally   
   more of a problem than of a solution because of exactly that problem. You do   
   not get a good directional diagram without the cone decoupling its outer   
   area when reproducing high frequencies, whatever that is in the context of   
   its working range. If you insist on using loudspeaker units only in their   
   piston range you end up with a 10 way system, ie. with 9 crossover-points   
   you need to get "just rightø".   
      
   > My theory is that small rigid cones with high excursion move as much   
   > air as effectively as a huge cone with less excursion and perhaps not   
   > as structurally stiff.   
      
   Yes, that is a good "volume displacement" understanding, but a small cone   
   with little or hardly any excursion coupled via a horn has both advantages,   
   and then quite a few other problems.   
      
   It is always a matter of multiple tradeoff, and the art of the designer is   
   where to place them. The perfect loudspeaker has zero area, since area is   
   problematic, and zero excursion since excursion is problematic, but with   
   excursion and area both approaching zero the sound output does likewise.   
      
   > -CC   
      
     Kind regards   
      
     Peter Larsen   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)