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
In-home trial until you can come to your own conclusion. Both companies you've mentioned will work with you on making sure you're getting what you want even if it isn't their product. I just sent back to SVS their SB-2000 in favor of an Hsu ULS-15 MK2 which was better in nearly every way minus size, but that size includes a 15" driver rather than a 12" that just plain moves more air. It was also producing much more defined, musical bass whereas the SVS seemed better for HT use. I would caution you on getting a sub with passive drivers (T7i/9i). Quality is not the goal in this design, the goal is get more out of a smaller enclosure. Happy hunting! 

http://www.hsuresearch.com/products/uls-15mk2.html 
Here is an Interesting  product that I am looking into.
 MiniDSP 2x4
  info From Audioholics Youtube
https://www.youtube.com/watch?v=Mq05vAAnryY
It looks very cool and affordable for whatever brand of subwoofesr you may end up with.
On Amazon
$108.00  and the Mic shows $106.00.
miniDSP 2x4 description from Amazon
  • Flexible Digital Signal processor (24bit/48k)
  • 1 x miniDSP 2x4 Plug-in Software License included
  • The miniDSP 2x4 is a high fidelity/high performance A/D D/A converter, crossover, parametric/graphic equalizer and analog inputs /outputs
  • USB self powered or DC power supply (not provided)

Also parts express shows a MIC that would work  for $88.00.Lets you manage multiple subs and tweak in all kinds of ways.
I recently purchased the new bowers and Wilkins DB3D sub. it is one of the most musical sub I have ever heard. It is fast and iron fisted tight.( 2 opposed 8” woofer with a 1K amp. It is absolutely seamless with my speakers. I know it wont get much love here as it is expensive. There are endless software adjustments with this sub. I believe its almost impossible not to get seamless integration with any speaker. 
I'm not yet ready to buy used equipment. I don't know enough. I'm going to buy new so I can return the item if I make a buying mistake.