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

Dear @folkfreak  : """   improving both the full frequency range and the ability of the system to resolve subtle room cues will do much more to improve bass quality than adding any subwoofer..."""

with passive speakers in a room/system your statement can't be true if we are talking of " true full frequency range " quality performance levels.

Every thing the same maybe we can be " near " to a room/system with subs but can't even it and of course that outperformed is out of question.

The Harman white papers is science and your statement is something different with a different foundation.

Full bass range first main target is evenly low bas dispersion at seat position. The only way that you really can understand it against what you listen through your room/system is to try there the subs " superior " alternative .
First hand experiences on that critical bass issue is a must to have.

As I said we can be near or we can have very good quality performance through our room/system but.........the integration of subs is a little step ahead and in a high-end those tiny/little steps forward means something for the better.

Some day you should try or should not  ! !  ? ? .

Regards and enjoy the MUSIC NOT DISTORTIONS,
R

raul I'm having a hard time understanding you, just the language barrier.
You can get perfect bass response at the listening position but it requires digital room control to do it. Getting reasonably smooth response through 
out the room requires a savvy approach to acoustic detail. But, even under the best circumstance you can not get perfect bass response unless you make your room an open amphitheater, a bit hard to heat. 

No such thing as perfect bass response...varies by venue!  So, that being the case, one can relax and get 1 or 2 subs for their system and play around until your happy with the sound.  Doesn’t need to be over engineered or killed with angst!  Have fun, grab a brew and enjoy the tunes.

Dear @mijostyn : """ But, even under the best circumstance you can not get perfect bass response...."""

absolutely rigth, we never can get " perfect " bass under no-circumstance.

Our target must be try to approach that " perfect " bass range, is the best we can do it.

The low bass quality performance at my home is very good ( not near " perfect ". ) and is very good only between a limited space/distance around the seat position, not over the whole room. I’m lucky enough that the low bass response in my place does not have a negative effect with my analog rig that is seated in between the speakers/subs. ( at least I’m unaware of it. ) that’s a position totally out of my sweet spot.

I had opportunity to listen to great home audio systems where only a few ones uses subs and as with my own system the best system overall performers are the ones with subs but one system for the owner priorities.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

dave_b:" No such thing as perfect bass response...varies by venue!  So, that being the case, one can relax and get 1 or 2 subs for their system and play around until your happy with the sound.  Doesn’t need to be over engineered or killed with angst!  Have fun, grab a brew and enjoy the tunes."

Hello dave_b,

     I completely agree that there's no such thing as perfect bass response, especially in such a compromised space as a domestic room. I now consider the number of subs and their configurations more as available method options that can be measured, both subjectively and objectively, and ranked in their relative effectiveness in typical rooms.
     I'm one who took your advice about four decades ago and got a decent passive sub with a 12" driver, and an Adcom GFA545 class AB amp to power it, in an attempt to attain better bass response, extension and impact in my room from an early system that lacked all 3.
    It was around 1980 and I was trying to attain better bass response not only for music but also for my first home theater attempt and incorporating Dolby 5.1 surround sound audio into my system.
     This is how and when my experience using a single sub in my system began. As I recall, it was exciting and fun to experiment with sub positions and settings for the first time.  I was able to attain very good bass response at a single listening position for ht. For music, the bass was more prevalent and had more impact at my listening seat but clearly did not integrate well with the fast and smooth midrange/treble response of my planar-magnetic panel main speakers; I consistently perceived the bass as a bit lagging and disconnected.
     Years later, I bought a self-amplified Klipsch sub with a 10" driver from a friend and experimented with using 2 subs running in both mono and stereo configurations. I had difficulty distinguishing a significant benefit with both subs along my front wall in a stereo configuration as compared to mono configuration. But I did notice the bass seemed faster, smoother and better integrated with my main speakers from my listening seat after I used the 'sub crawl' method to sequentially position each sub.
      I finally concluded the bass sounded best to in my room with both running in mono, one along my front 16' wall about 4' away from the right corner and the other about mid-point along my left 23' wall.
     I was convinced about a decade later by James Romeyn, and extensive related research on the subject, to purchase and home audition for a 4-week in-home trial period the Audio Kinesis Debra 4-sub distributed bass array system all powered by an included 1,000 watt class AB mono amp.
      As some of you know I've already stated about 2 gazillion times and climbing, the Debra system has provided the best bass response in my room and system that I've ever experienced.
     The bass is extremely natural, seemingly effortless, amazingly detailed and integrates seamlessly with my fast Magnepan 2.7QR panels. It's capable of accurately reproducing whatever type of bass the content calls for; rhythmic, solid, taut bass with natural leading edges and decays on music as well as sudden, dynamic bass with dramatic impact on ht and music.
    I was originally contemplating just buying 2 high quality traditional self-amplified subs that were larger. But I rationalized that the Debra would be about the same price ($2,800) as 2 expensive subs and, based on several very positive pro reviews and the impressive published scientific results of how well the dba concept works, that I shouldn't pass up the chance to try it out at no cost except time and determine for myself how well this solution actually works.
    Well, the results far exceeded my expectations. I now consider my system's bass as state of the art and honestly can't think of a single bass performance quality that needs improvement. Oh yeah, and this sota bass response is perceived throughout my entire 23x16x8 foot room including all 6 varied seating positions.
       I now consider the bass quality of systems using 1, 2-3 and 4 subs as good, better, best. Why waste time messing around with 1-3 subs and having some 'fun' when you could just buy an A K 4-sub dba, or build your own custom dba and have a blast? You'll have the rest of your life to relax and enjoy it since you certainly won't, IMHO, be searching for a better bass system.

Tim