Serie R-528 is the flagship model for Serie R. As such, it is capable of driving even large rooms and large speakers with ease. R-528 combines a heavy die cast frame, air-dried hand thrown 12” paper cone, 4-layer voice coil and long travel suspension with a unique REL carbon-carbon superlight passive. This results in the driven surface area of a 17” driver. Driven by a powerful 500W next-generation Class D amplifier that is perfectly mated to the high power 12” driver, R-528 is a powerful, concussive device that plays exceptionally deep with high output.

Serie R-528 is exquisitely crafted, grounded by a thick billet backplane milled from 6mm T6063 aerospace grade aluminium. This backplane doubles as a heatsink, thereby eliminating an external heatsink resulting in a cleaner, more modern construct. Naturally a full REL connectivity suite is featured using high quality gold rca’s, Speak-on High Level Input and separate .1 inputs. R-528 provides independent volume for High level as well as .1 for perfect flexibility.

R-528 features a next generation Class D amp capable of great speed and high current while keeping power consumption low when not in use. At 550W, and high current delivery R-528’s amplifier is capable of keeping up with large-scale instruments such as pipe organs and the most demanding of home theater soundtracks.

One of REL’s secrets is embedded within our input and filter boards. These are so secret that even now, every unit is encased within an impregnable compound that ensures destruction of critical components if disturbed. These direct circuits allow all the speed and transparency of bass REL’s are famous for and R-528 crosses over as low as 25Hz, ensuring the ability to blend perfectly under even very sophisticated speakers.

R-528 features a die cast aluminium heavy frame that better controls unnecessary vibration resulting in greater purity of bass. The cone structure is air-dried, hand thrown paper—each takes one week to produce. A high power handling 4-layer voice coil ensures the ability to accommodate large output signals with ease. The carbon-carbon passive is a special design that adds very low mass but more than doubles the driven surface area, producing a unit that acts like a fast, lower mass 12” but has the output of a 17” driver.

Cabinet Design: While every review of Serie R notes their exquisite finish quality (Serie R features 9 layers of hand rubbed lacquer), less visible but more important to the sound quality is the instrument-grade bracing employed within. Every Serie R features laminated hardwood internal spars. R-528 uses a full height spar that runs top-to-bottom up the side panel, continues across the entire top in one unbroken run. Hemi-secting this across the top plane is an additional spar that continues down the entire height of each side panel. The effect is to split each large panel into much smaller panels with higher resonance points that are well damped. This technique is a huge contributor to the speed and clarity of Serie R.

REL Theater Reference: Note the High Level Connection that allows seamless blend of sub with main speakers. Note also the .1 input which can be used simultaneously with the high level connection to provide a unique Home theater experience that provides truly immersive bass due to the restoration of low bass in the soundtrack to the main speakers.