Someone just audition my 10R and he mentioned Velo has more impact than Klipsch Sub12 (which he just auditioned). My hall also open to dining about 20' x 40'. So you must audition if you have the chance and see which one you like more.

Room Dimensions - 13' 10" W x 21' 7" L x 8' 6" H

System:

Projector - Panasonic - PT-AE3000U
Projection Screen - CARADA Criterion Series 128 Inch Diagonal - 2.35 to 1
Preamp/processor - Integra DHC-9.9
Amplifier - Wyred 4 Sound
Channel layout:
500w - Front R/L/C
250w - Rear R/L/RS/LS
Tactile Transducers - 2 original ButtKickers
Processor for tactile transducers - Parasound C2 predecessor to DHC-9.9
TT amplifier - Crown K2
Blu-Ray player Denon DVD-3800BDCI
Speakers: Klipsch
Fronts - RF-83
Center - RC-64
Surrounds RS-64
Subwoofers - Dual Seaton Sound SubMersives, Dual Velodyne DD-18's, HSU ULS-15 QuadDrive System
Room Correction - Equalizer - SVS AS-EQ1
Traps - GIK Tri-Traps in all four corners from floor to ceiling, 242 panel arrays on side walls, RealTraps Diffusor rear entrance door

Things are getting too technical for noobie like me. LOL.
FR graph is useful and another way of interpreting figures.
I more interested to see waterfall graph to see controlled of a good sub.
I could only judge them by ear. 

no need sub25 very powerful but hard to check price 
if i take SVS PB13-Ultra wont making boom boom high output like boom very louder
htkaki i did pm u u did see picture look ported 

performance wise??

added to cart.. huhu

3. One shortcoming about the Polk is the lack of an LFE input: you only get RCA and speaker line inputs meaning that there is no way you can bypass the internal crossover of the sub. Considering the market it's aiming for, this shouldn't be too big of a problem for most people, but owners with good receivers might be a bit vexed by this. Also, do not hookup the sub through the speaker line: it'll lose a fair amount of sound quality from forcing the bass through small gauge wires. Hook it up through the RCA if at all possible and you will be greatly rewarded.