Vertically Stack Your REL Subwoofers for the Ultimate in Bass Performance: Hi Level Baseline Blue Line Array Connectors Are Compatible with Series S, HT/1508, and No. 25 Subs Looking to create a line array of REL subwoofers for the ultimate in low, midrange, and atmospheric bass – to say nothing of harmonic complement that will have you on the edge of your seat?

You'll need a pair of Hi Level Baseline Blue Line Array connectors. Compatible with REL Series S, HT/1508, and No. 25 subwoofers, they are your pathway for building a stack of RELs to augment your main speakers and deliver incredible musical and film experiences.

Read more about the benefits (and surprising accessibility) of REL line arrays below. If you haven't heard a line array, you might well think this is just about pure power and ludicrous mode output.

While you wouldn't be wrong about their potential for massive output (an 812 array produces 6,000 watts of continuous, not peak, power with some 700 square inches of main driver with another 700 square inches of passive radiators exhaling into the room), the real reason for owning a REL line array has more to do with all the amazingly tactile qualities the highest-end music and film sound systems strive to provide.

We're talking effortless soundstaging, speed, delicacy, slam, warmth, body, and holographic imaging as well as movie sound that rises to and fills the entire height of the screen. Line arrays aren't just about stacking subs to make more output.

Each subwoofer's output pattern – how sound emanates from each sub must be compatible with the vertical stacking feature or more harm than good can take place.

Each sub in a proper line array must be individually adjustable for every parameter – output volume, crossover setting and phase – in order to properly tune the line array. The attribute in REL's latest range of drivers that jumped out was near-reference levels of power combined with class-leading self-quieting.

The latter refers to a 10" or 12" driver's ability to output tremendous levels of sound, then immediately quiet without continuing to ring. It takes both of these characteristics to make a line array state of the art.