How do SVS subwoofers compare to REL?


I'm looking for subwoofers (one or two) that have a very "tight" natural sound and are not overly boomy. In the future I hope to pair them with some Magnepan speakers. Magnepans are known for having a natural sound, and I want to compliment that.

I've been told that the REL subwoofers (e.g.,T/9i or S/3 SHO, etc., are a good match for Magnepan speakers. However, SVS subwoofers have also been recommended to me.

I don't have any background in high-end audio, so I am interested in opinions of folks here. Are SVS subwoofers considered generally as good as REL in regard to the features I'm interested in? Is either clearly superior? (I had never heard of SVS before yesterday.)

Which subwoofer size (in REL or SVS) would be a good match for a pair of Magnepan 1.7i in an 18 foot x 15 foot room (ceiling about 10 feet) with carpet on floor?

I'm looking at these so far:

REL T/9i Subwoofer about $1300
REL Acoustics S/3 SHO Subwoofer (Super High Output) about $2100
SVS SB-4000 13.5" 1200W about $1600
Any other recommendations?

Total subwoofer budget is around $2600 max. ($2000 or less would be better.)

Also, I believe it is better to buy two smaller subwoofers, compared to one larger one, right? (I'm just not sure where I would put two. Placing one is easier in this room. And I plan to connect everything with speaker wires, not wireless.)

Thanks

lowoverdrive
I use a single REL T5i in a 12' x 20' room with Harbeth P3esr small monitor speakers.  The specifications indicate the Harbeths start to roll off at 75 hz.  Whatever the specs, the influence of the room will dominate the perception of bass.
I have somewhat limited options for monitor placement.  For optimal listening with my system in my room I pull out the speakers into the room and have more of a near-field listening experience.  Bass frequencies being much less directional (perceptually) allows me to move my sub around to get the most enjoyable results.  When I was setting this system up, I was on my hands and knees scooting the sub around until I liked what I heard.  It's not a symmetrical arrangement, but it allows the little T5i to adequately (at least for my taste) activate the room.  I may try DSP room correction some day, but I find that jiggling things around and listening works pretty good.  I would work with placement and room corrections before surrendering to the digital dark forces.
Keep in mind this works with my system in my room for my listening tastes.  I don't listen very loud, and I prefer smooth and buttery sound over bright and articulate.  My system sets up a somewhat miniaturized 
user experience, but it's all there – detail, clarity, soundstage, dynamics, and, most importantly, an intangible I'll just call musicality.
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One more thing- in talking with several so-called experts calling around before buying I was told by all that 10” or smaller is ideal for tight bass that is fast/quick and better suited for musical enjoyment.  You want the subs to keep up with your speakers in reproducing the music.  Larger subs go lower and match better for home theater use.  I have a larger room than yours and two REL T9/I subs did the trick beautifully.
Hi lowoverdrive,
You have gotten some great feedback.
I have always associated SVS with Home Theatre Setups.

I included a link on the REL site to check out their recommendation on Sub Pairing for what you currently have. I would follow their advice at least for now and save yourself some $$ until you are ready upgrade to the next model Magnepans? 

Whenever you are ready, and want to continue to save some $$$ on the upgrade - The B-1/ B-2 are some of the best models REL produced. They are extremely musical. No longer produced but can be found on Agon and other sites from time to time.

Have Fun.
https://rel.net/speaker-pairing