Subwoofer for Kef LS50 Wireless II?

As far as REL is concerned, I have to agree with @missioncoonery. Using High Level Speakon connector with an after market cable is substantially better than using low level. I have tried this with several amps and speaker combinations. At least in my systems, high level is noticeably better.

@audiocanada -- I recently sold my KEF Wireless speakers (first version), and truth be told I was never satisfied with the subwoofer integration (REL T9i). I tried all kinds of configurations. My suggestion is that if you cannot benefit from the high level connection option on REL, save your money and look at other options from SVS or HSU, etc. IMO, REL’s special sauce is their high level/speakon connectors, otherwise they’re not any better than a myriad of other subs in the market.

Fiezta75....Ive heard HSU products,a couple different ones loaded with 15s ported and ports stuffed..maybe ok for home theater( boom boom) but only a fool would compare the new line of Rels/ S and above to that.I dare you to go listen to the #25  and not come away with a different tune. 

thanks for the responses
I've used the recommended settings on the SVS app as directed by their support team after advising the of the speaker pairing, I've also done the same thing with KEF support
from there I've adjusted to taste and performed the sub crawl
I'm afraid my room is currently not suited well at the moment for audio, open concept and hardwood floor, factors which will be addressed at a later date
ultimately the tonality of this sub is not doing it for me, I'm not hearing nuances or texture, more of a one note thumper, and a tad too much audible distortion when you push it on a track like Bass I love you, the unit has performed very well on movies
i think i will in fact skip REL due to the inability to connect via high level and start going up the chain further starting with a JL Audio dominion and then possibly a Rythmik Audio F12 G
budget permitting I would like to end this with a pair of JL's 10' fathoms

audiocanada, clearly your not overwhelmed by the SVS application. I hope your within the SVS audition period and able to return the unit.
Unfortunately, subwoofer digital processing is not equally designed.

Aside from my Velodyne Plus' my only other first hand experience with your short list was with JL Audio's v1 A.R.O. which auto equalized the loudest peak with no manual EQ adjustment. Their D.A.R.O. v2 is a multi band auto equalizer. Their CR-1 has a great deal more manual control.

There are third party products such as DIRAC which seem to have the flexibility your room may need. I hope you made note of your rooms loud bass modes and its nulls as you usually only need to do this once.

The AudioKinesis Swarm subwoofer system is another alternative that many have found very satisfactory.
Your in the mob now, don't give up. 

    

OP,  Auralex Subdude platform under the sub will help to get the bass under control away from one note and more articulate.  Especially if you are not at foundation level and room has suspended plywood floors.