For S/510, every aspect of the previous generation’s inner workings was examined without regard to its critical and customer-driven success. REL turned a fresh eye to power requirements, driver improvements, and specialty filters, upgrading each-to extract all the extra performance possible. All this alongside the cabinet refinements necessary for those upgrades to emerge cleanly. This latest S range is a triumphant development that has exceeded every expectation of REL's design team.

The requirements were for far stronger deep bass output between 20-35 Hz, vastly improved theater dynamics, and an even more open and spacious sound field that benefits both music and film. REL turned to their NextGen3 amplifier, tuned to 500 watts with substantial reserves of power, added a light film of carbon fiber to the rear of the driver to handle the extra power, and developed two new sets of custom filters to extract the utmost in brute force and spaciousness. Finally, REL imbued S/510 with the ability to be stacked in 4- or 6-unit line arrays, just like their reference models.

S/510 required upgrades to its ContinuousCast™ Alloy Cone to allow it to survive its massive power upgrades. To permit its thin, aluminum cone to survive 500 watts and incredibly long stroke, REL added an ultra-lightweight backing of pure carbon fiber strategically placed over portions of the rear surface of the cone. This produces two benefits; it strengthens and stiffens the cone and also eliminates reversion, wherein the back wave inside the cabinet is now prevented from interfering with the main launch of bass into the room. The result is more accurate and far louder deep bass.

S/510's uniquely tuned passive radiators use special suspensions, now with an additional 8mm of linear travel, to produce performance unlike conventional subwoofers. REL's new SuperProgressive™ passive radiator produces extremely long travel allowing for very loud output while retaining the variable stiffness of its suspension. This allows it to act like a sealed box compact 12” design at low volumes and a high output 14” design at its limit.

At 500 watts the NextGen3 amplifier is borrowed from REL's former flagship model and produces huge reservoirs of power and current. The 20%+ increase in power (the previous version was 400 watts) is needed to deliver the high output levels needed for modern theater, as well as to produce the extremely deep bass in a high-end 2-channel system. This increase in power is necessitated by REL's development on the musical front of an all-new circuit termed PerfectFilter™ that balances both frequency extremes.

PerfectFilter performs two seemingly disparate qualities; extending the strong, even response of the extreme low end of bass frequencies while simultaneously opening up air and delicacy in the middle and high frequencies of one’s system. Additionally, REL applied customized PureTheatre™ filters to allow S/510 to keep up with modern theater effects without breaking a sweat.