Rel vs the world


So whenever you look for subwoofer recommendations for 2 channel hifi, one name keeps dominating the conversation.. rel. And the flagship no 25 is seen as the ultimate subwoofer by many. My question is, has anyone compared well made but more affordable subwoofers (JTR, PSA, Rhythmik) to rel subwoofers (especially no 25) and go equally good or better results with the more affordable subwoofers?
Also thoughts on effects of cone material on sound in subwoofers? I am very interested in the choice of using carbon fiber cones on speakers like Alon in Magicos and Michael Borresen in his speakers. When I saw this in the rel no 25 I wondered if that was one of the reasons people were impressed with its performance. I found this article that Tom from PSA sent me pretty interesting.
"Myth: Cone Material Affects the "Timbre" of Subwoofers

At low frequencies, in the bass region below 125Hz, the cone material has no effect on the sound. If it did it would only be because of peripheral side effects such as a large change in the moving mass of the driver, or a cone who's strength and stiffness is deficient for the application allowing a lot of flex and distortion. A subwoofers cone or diaphragm should be stiff enough to not flex appreciably even when under heavy air loads. Any sufficiently stiff subwoofer cone would have resonances or breakup modes which are well beyond the bass range and should be inaudible with a typical low pass filter applied. If we have 3 identical sub drivers with different cone materials, one with an aluminum cone, one with a carbon fiber cone and another with a pressed paper cone and all are adequately stiff and the total moving mass of the driver is within a few percent of each other they will be indistinguishable from each other in a blind listening test.

The main take away here is that subwoofer cone material choice is primarily a consideration of strength/stiffness/durability/cosmetics/cost and weight. Sound is not one of those considerations.
"https://data-bass.com/#/articles/5cbf5e7357f7140004d6d0ec?_k=o4xuea


smodtactical
I went from “I’m not running subs no matter what” to buying 2 Rythmiks. I’m a Rythmik fan. Bought 2 for less than 1 t9.
I can't even tell they are in the room until I listen with them turned off.

This has been my experience, as well.  The bass is just there.  It doesn't stand out.  You don't notice the subs.  You just have good bass, which you notice immediately if you shut them off.

I can't really compare my RELs to other brands, though.  I do own an SVS cylinder sub I use for movies, and it is great for that.  I've never tried it for music, so I can't say.  I used to have a Def Tech SuperCube sub, which got killed by lightning and replaced with the SVS, but again, I never really used it for music much, and it's long gone, so I certainly can't compare it.

What I can say is that whatever REL is doing with their high-level circuit, it works as advertised.  Follow the setup procedure they recommend as closely as you reasonably can in your room, and the subs (T9i's, in my case) do what REL says they'll do.  That's a really nice thing to get in a product.
I had several (2 subs) REL subs, Martin Logan Gothic,  Balancedforce 210, Velodyne DD10”, and evening Miller & Kreiel. I went with the JL Audio Fathom 113’s and didn’t look back. I’ve sampled the REL No.25. I’m running the Wilson Audio Maxx 2 which in theory don’t need a sub or two for that matter. With the Wilson Audio Watch Dog Crossover, it works wonderfully with the JL Fathom 113’s. You can’t go wrong with the REL No. 25, Martin Logan Balancedforce 210 or 212 or the JL Audio Fathom 112 or 113 in my opinion I’m in Audiophile Heaven. 
I've owned the Stadium 3 and S/3 and now a SVS SB3000.  I like how SVS uses an app to dial it in, plus it goes subsonic, which is nice.  I like the sealed box my system.  I would like to know which @Audiorusty thinks has the most chest thumping slam.   
After I discovered Rythmik and got two of these (with Danny’s drivers), my RELs got sold quickly...The REL hype train crashed hard!

http://www.rythmikaudio.com/F12G.html

I also have 2 of Danny’s DIY open baffle dipoles to help my maggies in a 2nd room.

Danny Richie is a gift to mankind!
And America makes the best subs...It sure isn’t England! (Patriotic Brits are gonna hate me today lol).