Where are the subs?

Hello dbphd,

     I'm glad you're enjoying your system so much in a new room.  However, I believe your initial experiences in your new room are more a fortunate combination of factors than something you can rely on experiencing on a consistent basis with a larger sample size of source material.
      Your  Kef Ref 1 monitors, I'm assuming on speaker stands, are excellent speakers with exceptionally good bass extension for a monitor type speaker of about 40 Hz.   As you know, The Bach Toccatta and Fugue BMV565 has deep organ notes that likely require the full bass extension of the Kef's bass drivers at times.
     I would highly recommend utilizing your Velodyne HSG-10 subs and your xover in your system.  Not only because you'll be gaining the capacity of high quality bass reproduction of most of the bottom octave in any music (16-32 Hz) but also because you'll be relieving the Kefs of the burden of trying to reproduce bass frequencies at their woofers' physical limits of about 40 Hz.  
     There's also the added benefit of relieving your amp(s) from needing to supply the significant power the Kefs would demand when attempting to reproduce bass frequencies near their limits.  You'll notice the Kefs have an improved sound quality performance from the mid-bass through the midrange and treble with a greater sense of effortlessness when you add your subs and xover back into your system.
     You may also notice overall system performance improvements by raising the low-pass cutoff frequency a bit.  
   
     If you'd like state of the art bass response in your new room, utilizing 4 subs in a distributed bass array configuration would provide it.

Tim
  

The 14' X 19' room used for HT as well as music has a 100" projection screen, and two HGS-15s with SMS-1 bass manger that can make you feel pressure on your chest.  Unfortunately, both need repair, so the only functional subs in the room are two HGS-10s that are not connected.  I'll reconnect the HGS-10s, but really need to haul the HGS-15s to LA for repair.

It's great to get a pleasant and unexpected surprise once in awhile.The room is so important!I'd be interested to know your impressions with and without the subs. 

wait a few weeks before you try to put the subs back in...the room and set up are certainly crucial, but there is only so much deep bass those speakers can put out...

Hello dbphd,

That’s perfect! Get the 2 HGS-15s repaired and prepare to be amazed. If you’re using this room for ht and music, using all 4 positioned in a distributed bass array(DBA) will provide sota bass response for both.
This DBA concept works extremely well in virtually any room and with any pair of main speakers. I assure you that the results will stun you.
I use an Audio Kinesis Swarm 4-sub DBA system in my 23’ x 16’ foot room for both ht and music and it’s been a true revelation how well it works for both. Here’s an Absolute Sound review of the Swarm system that describes the performance improvements it provides very well:

https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

Since you would be using a custom DBA system with four self amplified subs with individual settings for volume, xover frequency and phase, the proper positioning and settings configurations of each sub would be a bit more complex and time consuming but well worth the effort.
You also have the option of just purchasing a complete AK Swarm 4-sub system for $2,800 if you don’t want to bother getting your 2 subs repaired. The system consists of four 4 ohm subs with a 10" aluminum long-throw woofer that are each 1’wide x1’deep by 28"tall and weigh 44 lbs. A 1K watt class AB sub amp/controller is also included that allows for setting the volume, xover frequency and phase of all four subs as a group.
These relatively small subs would be positioned around the perimeter of your room with the drivers facing and just a few inches away from the wall. Each sub has spikes and the speaker connections are on the bottom. This improves the WAF since they look like solid wood pedestals or end tables when viewed from inside the room. My room has a crawl space below so I cut a small hole underneath each sub and was able to have no speaker wires visible.
But either with a complete kit DBA or a custom setup, I know you’d be thrilled with the results.
If you’d like to learn more about the DBA concept, just google ’distributed bass array system’. Those written by Dr. Earl Geddes and Dr. Floyd Toole will provide the most scientific and detailed explanations of how and why the concept works so well.


Tim