On Thursday, December 4, 2014 8:40:49 AM UTC-7, chuck wrote:   
   > On Thu, 4 Dec 2014 05:10:48 -0800 (PST), thekmanrocks@gmail.com wrote:   
   >>So given that, the question should be, are mfgs listing the   
   >>avg, max, or min impedance on the cabinet spec sticker?   
   >   
   >   
   > Since there is no standard,   
      
   Wrong, there has been in existence for several decades, a widely   
   accepted standard for measuring ans specifying impedance. IEC   
   60268-5:   
      16 Impedance and Derivative Characteristics   
      16.1 Rated impedance - characteristic to be specified   
         NOTE This is a rated condition in accordance with 3.2.1.   
         The lowest value of the modulus of the impedance in the   
         rated frequency range shall be not less than 50% of the   
         rated impedance. If the impedance at any frequency   
         outside this range (including d.c.) is less than this   
         value, this shall be stated in the specifications.   
      16.2 Impedance curve   
      16.2.1 Characteristics to be specified   
         The impedance curve shall be specified, with represen-   
         tation of the modulus of the impedance as a function of   
         frequency.   
      16.2.2 Method of measurement   
      16.2.2.1 The loudspeaker shall be brought under normal   
         measuring conditions in accordance with 3.2.2   
         conditions a), b), and d).   
      16.2.2.2 A constant voltage or current shall be supplied,   
         the former usually being preferred. The value of voltage   
         or current chosen for the measurement shall be sufficiently   
         small to ensure that the loudspeaker operates in a linear   
         region.   
         Note Measurement of impedance may be strongly influenced   
         by drive level. If the level is either too low or too   
         high, inaccurate results may be obtained. The data should   
         be examined for consistency at several drive levels in   
         order to establish the best conditions.   
      16.2.2.3 The modulus of impedance shall be measured at least   
         over the range of 20 Hz to 20 000 Hz.   
      16.2.2.4 The results shall be presented graphically as a   
         function of frequency. The value of the voltage or the   
         current shall be stated with the results.   
      
   > the manufacturers can list whatever impedance they want;   
      
   Well, more accurately: the manufacturers can choose to ignore   
   common, well established and agreed upon standards and can   
   thus make up any damned number they want. Unfortunately,   
   not a few do just that.   
      
   > within the range of impedances that the speaker   
   > has in its frequency range.  For example, some speakers rated at 4   
   > ohms dip below 2 ohms at certain frequencies.   
      
   And, if they so choose to follow the standard, they must state so.   
      
   Dick Pierce   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)