No. 25 commemorates the quarter century of REL building the finest sub bass systems, while pointing to the future and the next 25 years as it employs their most advanced design, engineering and craftsmanship.
No. 25 combines the power of an ultra-reliable 1,000 watt amplifier, with a lightweight and perfectly balanced carbon fibre 15” driver. All this is controlled by REL’s legendary filter sets and proprietary crossovers with 2 separate parametric equalizers permitting remarkably flat in-room response, while maintaining the speed and resolution for which modern RELs have become known.
REL want their customers to enjoy all this performance without being limited to only a few room locations, so they built-in LongBow™ wireless receivers into every No. 25. This design utilizes zero compression, resulting in stunning dynamics and bass extension without being tethered to a cable, while delivering sound quality comparable to competitor’s hardwired designs. It’s just another example of how REL strive to offer complete and thoughtful solutions.
No. 25 marks a new standard in cabinet execution, both for its physical beauty and the manner in which it manages the critical backwave propagating from the rear surface of the massive 15″ carbon fibre piston at its heart. The shape of No. 25 is designed to disturb and cancel much of the incredible force created by the inward stroke as No. 25 reloads for your music or film’s next set of demands. It is necessary to keep this backwave as silent as possible, while allowing the driver to “breathe” without compressing dynamics. The curvilinear cabinet walls deflect, diffuse and dissipate these waves into smaller cross plane waves. Minimising rear waves that eventually emerge as comb filtering — noise that cancels the primary bass — is what creates clear, purposeful bass that strides into a room with tremendous energy and clarity.
Comprised of 30mm thick (about 1 1/8″) Australian MDF, transected by hardwood spars that break up common mode resonances within the top surface of the cabinet and down its sidewalls, the bracing is not unlike the spars in a ship’s hull. Some may view this as excessive, but these are the lengths REL’s design team goes to to deliver the finest subwoofer extant, fully fitting of the title No. 25.
It takes huge power to invest the No. 25 with the shattering dynamics of which it is capable. The rugged beast of a 1,000 watt NextGen3 amplifier that powers No. 25 has already proven itself in the field in one of REL’s previous designs, making them comfortable with not only its startling sonic performance but also its reliability.
However, No. 25 is no mere exercise in excess, but rather a thorough exposition in the art of rendering sub bass, totally, completely and with great deftness in tonality, expression and dynamics. It is this ability to not merely play loud, but to bring to life the contrast between loud and soft passages that makes REL owners so passionate about their designs.
Closed box, front-firing driver
ACTIVE DRIVER SIZE & MATERIAL
15 in., 380mm long-throw, carbon fibre cone with inverted carbon fibre dust cap
PASSIVE RADIATOR SIZE & MATERIAL
LOW FREQUENCY EXTENTION
-6dB at 14 Hz
High Level Neutrik Speakon, Low Level stereo RCA, LFE RCA, LFE XLR, SMA for wireless antenna
High Level, LFE RCA, LFE XLR Daisy Chain Outputs
1,000 watts (RMS) Ultra High-Current Power Supply
NextGen3 Class D
Longbow (Optional), Zero Compression, Individual discrete D/A and A/D Encoders
FULLY ELECTRONIC SET SAFE
MAINS INPUT VOLTAGE
220-240 volts, 110-120 volts for certain markets
7 Amp semi delay 230 volts operation, 15 Amp semi delay 115 volts operation
W X H X D
29 x 21.3 x 30 in. (736.5 x 540 x 762 mm)
168 lbs. (76 kg)
Piano Black Lacquer, 12 coats