RCF SUB 708-AS MK3

Active 18" Subwoofer with Bass Motion Control!

The SUB 708-AS mk3 is a mobile, powerful 18-inch active subwoofer designed for live sound applications. It features a high-quality transducer and a powerful Class-D amplifier delivering sound pressure levels up to 133 dB with impressive headroom.

As the perfect complement to 8- or 10-inch speakers, it provides premium sound across all use cases. On the rear panel, volume, crossover frequency (switchable), and polarity can be adjusted. The robust, durable wooden enclosure with scratch-resistant polyurea coating is easy to carry and stable to set up. Thanks to its versatility and high output power, the SUB 708-AS mk3 is ideal for small to medium venues and mobile operation.

Legendary Subwoofers

RCF subwoofers are the first choice for many sound engineers because they deliver very high sound pressure levels even at the lowest frequencies, are active yet more compact than competing products, and offer long-term reliability with an output power impressive for their size. Your audience can look forward to a moving and captivating DJ or live music experience.

Power That Moves

RCF transducers are continuously optimized – as are the amplifiers. With 1400 W peak power, the Class-D amplifier achieves impressive sound pressure levels with ultra-fast attack and natural transient response while generating very little heat. The subwoofers are so energy-efficient they require no fan for cooling. The amplifier is mounted in the rear enclosure area on a fixed heat exchanger without moving parts. The stereo signal input path with crossover is optimized for low distortion and includes a modern limiter for added safety, preserving the tonal characteristics of the input signal at all levels. RCF amplifiers comply with maximum safety standards (EN62368-1) and are powered by a highly efficient yet ultra-lightweight switching power supply.

Bass Motion Control

To achieve extended bass reproduction and more power, the RCF development team replaced the standard high-pass filter with a groundbreaking technology: BMC (Bass Motion Control), an innovative feature that controls woofer excursion. The BMC-equipped enclosure handles even the lowest audible frequencies without compromising woofer stability – delivering a linear, extended bass range and balanced sound.

BMC is an algorithm that comprehensively analyzes the woofer’s dynamic behavior and restricts only excessive excursions based on this specific data. This allows complete freedom in signal reproduction by the transducer. Conventional high-pass filters aim to prevent woofer damage but also affect phase behavior. Thanks to the new BMC algorithm, this problem is now a thing of the past.

Workhorse for Touring

The subwoofer suits a wide range of live sound applications. The rugged multiplex enclosure is lightweight for easy transport and stacking. All models feature ergonomic, rubberized handles for simple installation and quick teardown. The M20 threaded flange on top allows combining the enclosure with many top units. The durable polyurea coating, powder-coated front grille, and robust enclosure withstand the rigors of frequent use and transport. The separate amplifier enclosure ensures efficient and reliable operation. Acoustic foam lining inside the front grille forms an additional barrier against dust and moisture. Since the subwoofer has front bass reflex ports, it can also be positioned in niches or recesses.