SVS and REL will provide dramatically different presentations.
If both manufactures offer no cost audition satisfaction return policies your selection would be determined within minutes using the familiarity of your system within your own home.
REL are sub-bass speakers. They begin to roll off much earlier and are down a substantial -6dB clouding the manufacturers rated low frequency response. Offering only two position phase, volume and detent crossover control. In an online brochure the manufacturer claims any further control to be "cheap parlor tricks." Apparently the manufacturer determines their product matching by speaker cost. Accordingly, changing speakers may require a sub-bass speaker change. Check out their list.
SVS entire economical line of subwoofers have a far lower measurable low frequency response. The SVS smart phone controlled application parameters also offers the flexibility to more closely match most any speakers low frequency presentation and your personal taste. Along with three adjustable EQ presets should provide synergy with most any future speaker upgrade.
Distributed Bass Array or Swarm would be another economical consideration. The four driver array all but guarantees the elimination of typical rooms bass modes. By eliminating the timing issues related to single or double front wall or near speaker locations the sensation of the arrays total room lock is an extremely gratifying subwoofer trait making it a serious consideration. Also compatible with most speakers. Good luck with your search.
avatar: Gene Czerwinski
