I almost dumped this thing. The question was, in part, how the answer got to   
   be in milli or micro, but I looked and saw that the variables entered were <1,   
   fractions of an inch. I guess that means that formula works in inches. OK, but   
   I just didn't think    
   of it fast enough. The answer was adjusted to the nearest convenient decimal   
   place.    
      
   Anyway, part of the reason I even asked is for speakers. Now let me tell you   
   something. You take a sealed cabinet and put a low impedance woofer in it, it   
   is going to suffer some low end loss which COULD be helped by a port or   
   passive radiator.    
   but the rolloff is twice as bad when it goes under the resonant frequency.   
   Could be 20dB/octave, who knows ?    
      
   With a sealed cabinet the rolloff is 3dB/octave. Or 6 depending on how you   
   look at it. But if you look to the bottom octave it is not buried 16dB down   
   like it is an a cabinet with a port or passive radiator, it actually has more   
   output down there.    
      
   As such it can be reasonably equalized electronically. Trying to overcome 20dB   
   is impossible, but say 9dB is not.    
      
   This does not have to happen in the amp. this EQ could be n the crossover.   
   They put 3 ohm woofers in some speakers and with the coil in series can barely   
   eek by with a 6 ohm rating. The impedance at 19KHz is like 2.5 ohms, but at   
   100Hz it is 40. They CAN    
   claim a higher impedance because of that.    
      
   But what is happening is that the woofer is getting a tilted response, some   
   maybe 15dB up in the lowest octave which will really bring it out in a sealed   
   system because the thing rolls off at a reasonable rate, not like 20dB/octave.   
   This works best with    
   solid state amps and the higher the damping factor the better.    
      
   So that bottom octave CAN be had with 8" woofers and at 110dB. What happens   
   with ported or passive radiator speakers is that they DO have greater output,   
   but form the port odr passive radiator it is out of phase. They try to tel you   
   it doesn't matter but    
   they are full of shit. YOU COME AND LISTEN, I can demonstrate, well I will be   
   able to soon.    
      
   Bottom line is fuck all this shit, I stick with the old designs. In my project   
   list are a pair of Boston Acoustics A-150 and Audio Research AR-93Q. I got a   
   pair of EPIs, I think 100C that have a great low end as do my Nova Six,   
   ELCHEAPO Radio Shack    
   speakers. And I prefer them to the biggest JBLs, Macs, almost anything in the   
   mid/hifi range. No ports. Less efficient. But better sound. the bass is tight,   
   it is almost surprising to some how well controlled the bass is yet still   
   responsive to the    
   lowest octave. Most ported speakers are like, m, , loose. You can control the   
   woofer electronically but you can't control the  air. With a sealed cabinet   
   for the woofer, you CAN control the air. there is nothing like it. I stand by   
   this until death,    
   speakers should not have holes in the cabinet. Period.    
      
   If you heard my system you would not argue. (not saying you are but...)   
      
   So they can keep their little one note bass box and the balsa wood "speakers"   
   and I will keep my three bucks that they are worth along with the three   
   hundred they get the idiots to pay for their fucking junk.    
      
   Anyone wants to argue, we make a date at a REAL stereo shop.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)