Sub to complement KEF LS50s: SVS vs. Rythmik

@mcreyn 
Point 3. Right?

@noble100 
Thanks for the help. My system currently costs less than a pair of KEF LS50s.

KEF Q150s - I paid $300
Monoprice Monolith Stands - I paid $75/pair
Peachtree Decco65 - $400 craiglist special
Google Chromecast Audio - $35
Sub - $20 craiglist special

I initially thought the sub would degrade from the definition in the Q150s, but it enhanced everything. Having some sub was better than having none. The casing of the sub says it is a Jensen JS1000-A. But looking at the driver underneath, I see the driver was swapped out for a Kenwood--possibly a car driver. Sorry for any heart palpitations this may have caused, but this is the reality of budget Fi. You'll be happy to know that I could hear the difference between Spotify and 16/44.1 once I placed the Q150s on stands. And know I can't go back! (Spotify and 16/44.1 sounded identical with the mains on a desk.)

I currently run speaker cable from the Decco65 to the speaker level input on the sub, then speaker cable to the Q150s. But I bet the Decco65 pre-out doubles as a sub out. Have to double check, though. Still, the Decco65 only puts out 65w, so allowing the sub to take over the probably helps free up power for the mains as you described, noble100. 

I have the crossover on the Jensen set to 50hz since that is the 3db falloff on the Q150. And I have the volume set appropriately on the sub to achieve a flat sound signature. 

The only way I would it would appear that I could daisy chain subs with the Jensen is through the speaker level input. 

As far as a sub upgrade, I have considered both the Rel 5Ti and SVS 1000. Rel seems to be of the high level input persuasion.

jdtalv, the SVS, and I've never even seen one. 

  Your going to need all the signal processing you can muster to begin a worthy crossover between the two unless you've considered an even more sophisticated method of manual multi band parametric variable phase, gain, and Q DSP, in which case most any box will do.

  Read as many DSP setup procedures as possible for a better understanding of how using a higher crossover point and adjusting the Q can attain a smoother transition that will more closely match your main speakers presentation in the crossover region.   

  My experience with integrating powerful subwoofers with small speakers has been quick and easy using a sub that seems to be out of production because of the manufacturers success in another field of endeavor. This same manufacture patented servo monitoring and control and found a better solution three generations ago. (calvint, you gave up too soon)

  This is in no way a substitute for proper positioning or the use of multiple subs which are delightfully explained here, elsewhere. Have fun with it.  

M-db

I owned 6 different subs from that manufacture, starting with their original 80s design. My  Rythmiks represent a step forward.  

mcreyn, 

As I said, I've never even seen one.  

Nice to hear of your satisfaction though.

My 2 cents from the 4 years of listening and enjoying experience with this magnificent speakers.

Buy a pair of competent subs that can go clean and flat as high as 100-120 Hz, because LS50’s response starts to weaken at these frequencues especially if you have them far from the back walls. If possible, cross them over at 100-120 to further relax them and improve the mids. Keep the subs close to the ls50 and you will enjoy. 
You can leave them full range as well just dial the sub volume adequatelly.
I enjoy them with a single b&w asw608 sub and the bass is adequate at the listwning position and very clean and articulate.