Cornwall IV and subwoofers

I have a pair of Klipsch corner horns, just the bass section.  The go to about 40 Hz and at 106 dB/1w are effective for most listening.  I would not add a sub, but built one anyway. 

I call the Klipsch "subs" because that seems to be the vernacular. 

I do have a sub-sub, which is a 14' transmission line with 4 15s.  Three of those.  TLs are narrow band but efficient.  I can't measure the SPL but it should be flat to 4 Hz and judging from vertical floor movement, about 5.2 Richter.  Good for rocket launches, end of world movies and such.  Maybe some music. 

Plenty of good stuff to digest here. Thanks again to all respondents.

Bill

SVS Micro 3000

good job. Easy to adjust. Solid 500W playing two directions. No more MUDDY bass because you can use the BEST gauge:YOUR ears, which differ from mine! Lol

Hi Bill, Excellent idea. Since the Cornwall's woofer goes up into the midrange using a sub will noticeably decrease distortion. Good subwoofer systems do both HiFi and theater well. The ideal subwoofer system for Cornwalls would require two 12 or preferably 15" sealed subwoofers and a dedicated two way crossover set to 80 to 100 Hz with a slope no less than 28 dB/oct. I would use a digital crossover with room control and delay capability. So, there is no need for fancy electronics in the sub. The best way to do this would be to go to Parts Express and get this, https://www.parts-express.com/Dayton-Audio-15-Reference-Series-HO-Subwoofer-and-Cabinet-P-300-7093?quantity=1

You will need two of them. They are super easy to build and the driver is better than what you get in most commercial subwoofers. The money you save can be spent on the crossover. I would also upgrade the plate amp to this,  https://www.parts-express.com/Dayton-Audio-SPA1000-1000W-Subwoofer-Plate-Amplifier-300-809?quantity=1