
       
       The NaO U-frame woofer system is an excellent compliment for any smaller 
speaker or speaker with challenged low frequency response. At the right the 
NaO U-frame woofer is shown with the Quad 63 ELS speaker. In such an 
application not only does the woofer provide deep, articulate bass response 
but also unloads the main speaker from low frequency duty resulting in 
improved midrange clarity and definition. The NaO U-frame woofer system is 
also an ideal companion to the Magnepan MMG speaker system.  
The NaO U-frame woofer system consists of an active, stereo 
crossover/equalization unit which provides the necessary transition between 
the main speaker and the woofer, and also provides the necessary 
equalization to extend the woofer's response to 25 Hz. The system is built 
around the Peerless 10" XXLS 830843 woofer. This woofer 25 Hz fs and Qts 
sufficiently close to 0.5 (Qts = 0.44) make it suitable for very straightforward 
equalization following the approach discussed in the section on Gradient 
Woofer Equalization, for Qts of 0.5 or greater with acceptable fs. For this 
application the 4th order high pass response was chosen insuring protection 
from over excursion due to excessive equalization below fs when other 
equalization approaches are implemented. This, combined with a quasi 4th 
order Linkwitz/Riley crossover between the main speaker and the woofer 
provide a seamless transition.
The NaO U-frame woofer system is sold as a DIY project in several formats: 
plans plus the require printed circuit boards (PCBs); plans with assembled and 
tested PCBs; or plans with completely assembled active crossover. The PCBs 
used are the same as those used in the Mini active crossover. The 
construction of the U-frame is left to the builder being the most cost effective 
approach. The plans include complete U-frame construction details including 
the required damping.
       
      
      
          PLEASE NOTE: These pages are now for historical purposes. Music and Design is no longer offering these products for sale.
	  
	  
      
      The NaOTM   U-frame Woofer system
By Music and DesignTM....
(Discontinued)