Will a subwoofer add depth and clarity to my system, or just bass?

jazz99,

     Woops, forgot about room correction.  You can run bass room correction optimized to your listening seat as part of step#6 above.  It should just further fine tune bass response at your listening seat but will have little to no affect of improving bass response elsewhere in the room.


Tim

Hello jazz99,

     For your situation, I'd suggest the SVS SB1000 (12"driver in a sealed box) would be the better choice than the SVS PB1000 (10" driver in a ported box) although either would provide a dramatic improvement over not using any sub with your Focal Aria 906 speakers..  They're both priced at $499 and are powered by the same 300 watt class D amp.  
     The PB1000 is slightly larger and generally considered better for movies and the SB is slightly smaller and considered better for music. 
     Your Focal bookshelf speakers on stands are only reproducing bass down to about 55Hz.  The human audible hearing range is 20Hz to 20,000Hz, with 20Hz being the lowest audible frequency and 20,000Hz being the highest audible frequency.  
     Your current system is reproducing none of the frequencies on your music between 20Hz and 55Hz.  Adding either SVS sub to your system will fill in this gap and you'll be amazed at what you were missing.  I believe the SB1000 sub will reproduce bass frequencies in this missing  frequency range more accurately and integrate more seamlessly with the sound frequencies reproduced by your Focals than the PB1000 sub can.
    For best bass response in your system and room, it's also very important to properly and precisely position the sub in relation to your listening seat.  Here's my suggestion of how to do this:


1. Disconnect your Focal speakers and place them and their stands temporarily outside your room.  You can mark the positions of the stands on the floor (colored tape works well) or just optimize their positioning as a final step in this procedure.
2.Hook up the sub and place it at your listening position.
3. Play some music with good and repetitive deep bass.
4. starting at the right front corner of your room, walk counter-clockwise around the perimeter of your room and determine the exact spot where the bass sounds best to you.  This is a critical step, so take your time and walk the perimeter multiple times if needed to find the precise spot that the bass sounds best to you (natural and detailed without being over-emphasized or attenuated).

5. Reposition the sub to the exact spot the bass sounded best.

6. Sit on your listening position seat and replay the music with good and repetitive bass.  Verify the bass now sounds just as good here as it did at your identified spot.  If it does, your sub is optimally positioned within your room.  If it doesn't, you'll need to repeat this procedure from step#2.

7. Reconnect your Focal spkrs and place them on the stands at the marked positions or reposition them again in relation to your listening seat for optimum tonal response and imaging.  I'd recommend running your Focals full range and connecting them to your amp as usual rather than connecting them to the SVS sub.  There's also no harm in trying both methods and using whatever method you prefer.

8. Set the desired low frequency cutoff frequency on the SVS sub.  This is an important step with the goal being the smooth and continuous blending of the sound from the sub and your Focals.  This will probably require some experimenting with the ideal cutoff frequency likely being somewhere close to 55Hz.  

     I believe an ideal cutoff frequency setting could be determined mathematically if we had all the relevant data but you're likely to arrive at a setting that's very close just doing it by ear and what sounds most seamless to you.  Try to avoid creating any holes in the combination's frequency response.

     My opinion is that, when you have everything positioned and configured properly, anyone listening to your system from your listening seat will just assume you have the best sounding pair of bookshelf speakers they've ever heard.  
      Lastly, I want you to realize that this system will sound great from your listening seat but there is a compromise that cannot be avoided when only a single sub is used; the bass response will not be optimized at multiple other specific spots in your room.  Less discriminating listeners will probably not even pick up on this unless they're sitting at a spot in the room where a bass mode exists.
     Bass modes are specific spots in any given room where the bass will sound exaggerated, attenuated or even absent.  I can explain bass room acoustics in more detail but I'd like to avoid turning this post into an even longer book.
     There are bass systems that eliminate the vast majority of bass modes existing in a given room which results in very good bass response throughout the entire room but they're more expensive and require more subs. I use one of these systems, called a distributed bass array system, but I think it's too expensive ($3K) for your budget, more elaborate (4 SVS SB1000 sized subs with a separate 1K watt amp) than is practical for a small room like yours and not necessary if you're content with optimized bass response at a single listening position.  

Hope this helped a bit,
Tim 

millercarbon:
"More pure gold. I’ve copied the whole post just to pose a pop quiz and see if anyone can answer: what one single letter best differentiates Duke’s highly informative post from all the rest?

Hint: to understand the answer is to understand the problem."

Hello millercarbon,

     I completely agree with you that audiokinesis keeps delivering audio gold by sharing his vast audio knowledge and experience with his thread posts.  I always learn a lot from his posts. 
     Now, your pop quiz question has me stumped:
     What one single letter best differentiates Duke’s highly informative post from all the rest? 

     I really have no idea but I'll take a stab just for fun.  

     Is it 'G'? 
As in g, I didn't know that.

Tim

Duke,

Excellent explanation and it all makes perfect sense to me.
I was thinking, however, that I may understand better than some reading it since I’ve experienced the transformation of perceived bass response in my room by using a DBA (distributed bass array) system.
I think the practical consequences of designing a DBA system based on utilizing the principles you explained does not really become fully understood until an individual actually hears the transformation themselves.
I remember James Romeyn describing the bass response I should expect in my room from his Audio Kinesis DEBRA DBA system and thinking it all sounded too good to be true.

In fact, I recall being skeptical right up to the point I pressed play after setup was completed in my room. It didn’t take me long to know James was telling me the truth. My honest opinion is that the transformation of the bass response in my room to state of the art was nothing short of miraculous, especially considering it was affordable ($3K) and done without any mics, room correction, room treatments or other special equipment.
I know you’re too much of a gentleman to use a thread post as a sales promo for your own products so I’m taking the opportunity to do it for you and Jim as a very satisfied customer. Besides, no one ever accused me of being a gentleman.
I can state with certainty that the DBA system works extremely well whether it’s an Audio Kinesis Swarm or Debra complete system or a 4 sub custom configuration with subs of your choice.
My main point being that I could write a book on how well it performs and convince no one but it only requires a short audition to prove to anyone. To mangle an old expression, a listen is worth a thousand words.

Tim