Sub to complement KEF LS50s: SVS vs. Rythmik

Great thread! I’m new to this hobby, and this is my first audiogon post. I just connected a sub to my KEF Q150s this week. It was a game changer. But I find myself saying "game changer" every time I add a new component. I keep thinking I’ll hit the point of diminishing returns for my money, but that hasn’t happened yet.

My question to any/all of you is, how do you connect more than one sub to your system? I connected mine via the speaker level input--speaker cable from the integrated to the sub, then from the sub to the mains. Paul at PS Audio says the speaker level/high level input best because it preserves the sound characteristics of the power amp, which also allows the sub to blend better with the mains. My thinking is that 2-4 subs may require connecting via the line level input, no? If this is the case, would you say that the trade-off for using the line level is more than made up for by the quantity of subs? Also, should my second sub be the same brand/model as the first? Or does quantity of subs outweigh brand consistency too? Thanks

@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.