Full range or subwoofer with bookshelfs for best bass at low to moderate volume?


I have an older subwoofer with bookshelf speakers and the subwoofer is dying. I listen mostly at low to moderate volume and am in the middle of changing over my system as my Pioneer Elite VSX 49 TXI receiver was degrading, also due to age. My question is whether a subwoofer with bookshelf speakers or full range speakers produce more bass at low to moderate volume? 

Current system:
Moon Audio 250i integrated amp
Angstrom signature 3 speakers ( 6.5", Seas drivers, 86 DB, 6 Ohm)
Paradigm subwoofer (needs to be replaced)
Denon 2910 used as transport
Looking for an analog sounding dac at this time

mtloriginal
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@mtloriginal,

Where is you general location? I have had very good success on the used market from my local c-list with good deals, reliability, and quality of subwoofers(Revel B15, SVS SB13 Plus, Paradigm Servo 15a).

Bill

@mtloriginal
This is a nice SVS sub that has been replaced with a newer mode (SB2000) . The price was $679.00 before it was discontinued. It is a bargain at this price ($399)!
https://www.amazon.com/SVS-SB12-NSD-400-watt-Controlled-Subwoofer/dp/B009F8Y7SO
Willland, thanks for the offer. The subs you listed are older and I am not looking for anything over 3 years old. 
Bob_reynolds and yogiboy, I was surprised and happy to see the good reviews on the SVS subs, hard to find a decent sounding sub under the $1000 list price. I really wanted something other than black, but may consider black at a later date.
Thanks for the replies.

mtloriginal