The REL Acoustics T/9x is the flagship of REL’s Serie T/x range, sitting below the Serie S and Reference lines in the company’s hierarchy. Despite its position as the entry-level range’s top model, the T/9x is a genuinely capable subwoofer designed by REL’s head designer John Hunter to deliver fast, articulate bass for both stereo hi-fi and home cinema systems.
Driver Design
The T/9x uses a dual-driver arrangement with a front-firing 10-inch active driver and a down-firing 10-inch passive radiator. The active driver features an extremely long-throw suspension, developed over months of tuning to increase dynamics, handle more power, and extend deeper into the bass. On every inward stroke of the active cone, it pressurises the cabinet and drives the passive radiator beneath, which fills out the lowest frequencies along the floor plane. This configuration allows the T/9x to reach down to 27Hz at the −6dB point.
Amplification
Power comes from a 300W Class A/B amplifier built around large transformers designed for high current output. REL favours Class A/B topology in this application because of its current delivery characteristics — while voltage gets a driver moving, current is what stops it and keeps it under control. The high-current power supply ensures tight start-stop behaviour, contributing to the speed and precision that REL subwoofers are known for.
Connectivity
The T/9x provides REL’s signature high-level input via a Neutrik Speakon connector, which takes a speaker-level signal directly from the amplifier’s output terminals. This is REL’s preferred connection method for stereo hi-fi use, as it allows the subwoofer to inherit the tonal character of the main amplifier. Low-level stereo RCA inputs are also provided, along with a dedicated LFE input for home cinema integration. For cable-free installation, the T/9x is compatible with the optional REL Arrow wireless transmitter.
Controls & Setup
Rear-panel controls include a variable crossover (low-pass filter), continuously variable gain, and a 0/180-degree phase switch. These allow precise integration with the main speakers regardless of room placement. The compact cabinet — approximately 340 × 370 × 393mm and 18.7kg — sits on aluminium feet and is finished in High Gloss White.
