S/812

The S/812 is the largest single-driver model in REL's S-series and the one I'd specify for a serious 2-channel system or a music-first surround setup. 12" forward-firing driver, 1,000W Class D amplifier, sealed enclosure, REL's signature high-level Neutrik Speakon connection that integrates with the main amp's speaker outputs rather than from the AVR sub-out.

The high-level connection is the headline difference. Connecting a REL via Speakon means the sub sees the same signal — and the same character — as the main speakers, which is why RELs integrate with stereo systems in a way that home-theatre subs never quite manage. For music, the result is bass that extends rather than overlays the front pair. For film, you can run high-level and low-level simultaneously and gain the dynamics of an LFE-fed sub plus the integration of high-level.

Tonally these are tight and articulate — fast attack, controlled decay, low room interaction at sensible levels. Extension is honest to about 18Hz (not the marketing 16Hz but close), and they don't rely on port chuff or over-EQ to get there. The sealed enclosure means group delay is minimal, which is what makes them sound 'fast' in audiophile terms.

Build is overengineered: cryogenically treated drivers, militarised electronics, NextGen5 amplifier topology. They'll outlast most rooms.

The high-end single-driver REL to buy when you've outgrown the T or S/510 line.