Separate subs for music and HT/surround

http://jtrspeakers.com/captivator-4000ulf.html
Buy one of these and crossover at 40. 😎

@Clearthink i could probably place the level inbetween...... gonna give that a try, hmmmm -8db and call it quits

The Velodyne HGS-15s are now behind the KEF Ref 1s, an HGS-10 aside each Ref 1.  The HGS-10s are connected to one of the SMS-1s, the HGS-15s to the other.  With the SMS-1s daisy-chained I can turn one off if I want only the HGS 10s or HGS-15s.  I've been listening with just the HGS-10s active and I like it for music.  Makes me wonder about replacing the HGS-15s with another pair of HGS-10s.

The Sanus rack makes equipment very accessible and is a joy to use.  Should have done that years ago.

db   

 Hello DB,

     It seems like you positioned your subs symmetrically in your room to make your system as visually appealing as possible.  However, I strongly suspect this positioning fails to optimize the audio bass response performance quality attainable in your room utilizing your four high quality subs. 
      I believe you'll obtain significantly improved bass performance, primarily noticed as improved seamless integration with your KEF main speakers, improved bass impact, dynamics, smoothness and naturalness, by positioning all four subs along the perimeter of your room in a distributed bass array configuration.  
     This is accomplished by sequentially utilizing the 'crawl method' beginning the search for the ideal positioning of the first sub at the front right corner of your room and proceeding counter-clockwise around the perimeter of your room.  
     Just continue positioning each sub optimally and sequentially until all four are located.  It's really up to you to decide whether you prefer to locate the larger 15" subs first, last or alternate between a 15" and 10" sub.  No matter the distribution pattern you choose, the ultimate audible result will be excellent bass response quality throughout your entire room.

     The bass results will be similarly smooth, natural and well integrated with your main speakers whether you deploy your current pair of 15" and 10" subs or if you deploy four 10" subs.  Including the larger pair of 15" subs will provide overall bass response that extends a bit deeper, has a bit greater impact and slightly better dynamics.

Tim

   I was unable to get two of my subs in the perfect crawl tested locations but they were close. The Auto EQ did take up the slack in my room.
   I ran my Earthquake, the DD-18 and two DD-12 Plus mastered from one of the 12s. I was able to closely match the equalization of the 18 to the others with the calibration mic at the listening position, individually running Auto EQ followed by a few minor Manual EQ adjustments on the Velodyne's. 
   Your listening space may not need all four units. What sounds good to you is key. There are no absolutes.