From: info@turneraudio.com.au   
      
   "patrick-turner"    
   Phil mentioned...    
      
   - show quoted text -   
   >    
   > ** The AR9 was first sold in 1978 and used two 12 inch woofers, same ones    
   > used in the AR11 released in 1977.    
   ** AR constantly refer to the above woofers as being 12 inch.    
   But they are closer to 11 inch, in reality.    
   I remember now there was something odd about the woofers in a friend's    
   AR11s.    
   The impedance curve of the AR11 was so wild I drew it out and kept a copy -    
   here is a listing:    
      
   DC       =    4.2 ohms    
   10Hz    =    5 ohms    
   32Hz    =  30 ohms    
   100Hz  =    4 ohms    
   500Hz  =   10 ohms    
   1kHz     =   4 ohms    
   2kHz     =   2.5 ohms    
   5kHz     =   2 ohms    
   10kHz   =   2 ohms    
   12kHz   =   2 ohms    
   20kHz   =   3 ohms    
   50kHz   =   8 ohms    
      
   BTW:    
   The low figures above 2kHz are because the 4ohm dome mid and 4ohm dome    
   tweeter are operating in parallel.    
   The owner was originally using twin wire he got from Tandy / Radio Shack (    
   14x0.14 stuff ) -  so each run was about 1.5 ohms resistance, plus about 2.5    
   ohms of inductance at 15kHz.    
   So I made him up some leads using "Tocord" ( aka Mogami cable)  with near    
   zero inductance and about 0.2 ohms resistance.    
   His mouth dropped open when he heard the difference.    
   ..  Phil    
      
   Before completely re-forming the pair of AR9 I was given to fix, I did    
   manage to get one working as it may have worked when new by swapping out    
   working mid/HF drivers so that enough working drivers were in the same box.    
   I found the acoustic response response using the middle position of mid-HF    
   level switches was anything but flat and extremely poor by my standards. I    
   don't recall any HF dips to 2 ohms as you state exists above 2kHz,    
      
      
      
   ** Please, read my post more carefully - it's the  *AR1 *  that has absurdly    
   low impedance above 2 kHz.    
      
   But your post said AR11, see above, re-quoted.   
      
      
   > IMHO, it is very easy to make a better pair of speakers than the AR9.    
      
      
      
   ** The various AR speakers I have seen and tested were riddled with unholy    
   compromises and evil Yankee dodges  - plus built as cheaply as possible.    
      
   Their Aussie built models were even worse, with plastic veneer  -  yuck.    
      
   But still better than Bose by a mile.    
      
   I'd certainly agree with you on that.   
      
   Ah, the un-glorious 1970s, full of Krapp from all directions. Hardly anyone   
   knew what hi-fi was about, and hardly anyone attended concerts with   
   unamplified music to calibrate their ears. Mostly ppl experienced music when   
   boozed up, smoking and talking    
   with ppl mostly liking highly processed pop music.    
      
   I cringe when I listen to some old records I have.   
      
   But now I much prefer the Brandenburg Orchestra. I think my mind grew to   
   become bored with the peurile efforts of dysfunctional pop stars full of   
   cocaine, and it now demands each bar of music be different to the others, and   
   to be the product of    
   cleverness, not stupidity.    
      
   See  http://brandenburg.com.au/site/2013-sydney-season/   
      
   Patrick Turner.    
      
      
      
   ...  Phil    
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)