SURPRISE,  SURPRISE !!  If anyone takes the time to read the product information offered by REL on line, they will understand that REL'S approach to sub design goes way beyond just adding lower octave bass.

-More enjoayble sound stage

This is something that does not get mentioned often enough. Although, it is probably more related to classical music recorded in a concert hall, more than other types of music, at other venues, or a studio.

There is a lot of ambient information carried in low frequencies, that add imporatant spacial cues. A bigger, deeper, better defined sounstage is the result.

I finally bought my first sub. It's a REL T5x and I love it.

Finally Learned: Subs serve much larger role than adding more low bass

My GF commented on how the addition of the subs really helped out the tonal balance in the high end- how the system became more relaxed.

I've had two subs for about twenty years.  Relieving the main speaker othe main speakers of the bottom octaves has several bebefits.  Less excursion of the woofer, lowering distortion.  It also takes load off main speaker amp.  And of course better bass.  On a side note, I recently put springs under the subs.  This added detail, more body to the bass.  I also have much less booming bass in other areas of the house.