What is the forums opinion of SVS subs?

YouTuber Nemo Propaganda does a good job of doing explaining the differences between the two brands. Might want to check him out. I too had a hard time with REL’s specs as on paper they don’t seem impressive. It’s hard to explain, you kind of have to hear one. They produce bass and have extension but it’s like there is no sub in the room. Just more low end articulation that seems part of the mains. The two brands are just different philosophies. No right or wrong, it comes down to one’s preference.

And

Rel prefers to run off the speaker-level output and doesn’t offer integration software but by nature is easier to integrate without it.

To me ^these statements^ translates to use a REL or two in a 2 channel system, and either add a n SVS or use a couple of them for HT.

it is hard to beat speaker level inputs and Analogue SIgnal Processing (ASP) for the two channel.
If one has a DSP then that means that they know what to do, but it is more work for the rest of us to overcome… (IMO).

Without disclosing specific models Nemo uses a questionable analogy of the personalities of two different women and another using two different German automobiles to describe basic differences with four subwoofers, REL, Rythmik and SVS and JL Audio. He also places something on appearances.

Three of these subwoofers is equipped with differing methods of equalization, two add room optimization all are vital in producing variable presentations. With the exception of REL they all meet or exceed their claimed low frequency response.

Better to give Nemo his twenty thousand leagues under whatever and begin with mrteeves’ philosophical differences.

All REL’s are sub bass speakers. Rythmik has optional frequency cut and boost and JL Audio F series has an internal frequency generator and a calibrated microphone to automatically (only) adjust the frequency response. All are set-it and forget-it subs.

The SVS uses a smartphone (remote control) based application that allows you to see what your hearing while making crossover, phase, frequency, Q and volume adjustments to your liking. And the ability add those settings and two others to memory presets. If you want the SVS to sound like a REL it’s up to you.

Best of all you can change the volume by remote control as well as the presets all from the listening position. Velodyne offered far more detail version of this almost two decades ago in their DD and DD Plus lines.

mrteeves, "No right or wrong, it comes down to one preference." All the best with your search.

In my personal experience, if spending less than $3-4K per sub, SVS takes the cake. I have two SVS SB-4000 in my room, which is 18x23 with sloped ceiling up to 18’, and the room is open to another room towards one back side. It’s a lot of space and these guys are fast and deep. I tried two SB-3000s and they were slower and not enough for the room, but still great considering their price against a pair of Rel T9i I demoed a week prior. The SB-3000 blow those away. 
 

I did also try a REL 212 SE and it is faster than the SB-4000s, but I couldn’t live without the smartphone integration capabilities of the SVS. Phasing is especially important to me, and REL doesn’t offer that until you get up to their reference series which run $4K+. At some point I will likely upgrade to something in that line. 

I own the SVS SB2000 Pro. It sits upon my homemade bungee trapeze which isolates the sub from floor. While waiting for delivery,  I didn't have much hope, To my surprise, the blending with my Klipsch Lasalas is wonderful. I had all but given up on ever getting a sub to play nice with the big floor standers. Previous subs include Velodyne, Polk, Sunfire and other brands. See? I really tried. Honestly I purchased it expecting to return it as a failed attempt or try again by getting up SVS's product line to a bigger better unit. (Crutchfield returns policy is easy)  Once set up, the sub did what every sub should- It simply disappeared and allowed the music to become the focus! Five Stars

I use a SVS PB2000 pro sub with my JBLL100 Classic speakers and the single sub really made my system go from pretty good to incredible.  Like others have said, their software to integrate the sub is excellent and easy to use.  You can make adjustments on the fly too. I was going to add another of the same sub but the system sounds so good with one, that I don’t want to spoil the magic.