The notion that a full range speaker manufacturer might make a “matching” sub to the main speakers is a flawed premise. Sub-bass may be the most demanding design brief in all of speaker design and the ability to do it well and reliably is beyond the abilities of almost all speaker manufacturers. The easiest way to tell if a subwoofer is a result of happenstance is to turn the sub around and look at the rear panel. Most possess low quality connectors that will oxidize and start humming in a few months or year, and usually use cheap black paint with white graphics. These are telling signs that the subwoofer was designed to produce a salable object for the lowest cost to the manufacturer. Moreover, these subwoofers usually feature drivers designed NOT to produce deep bass, a poor quality amplifier, and lack true filter capability or technology. While these subwoofers are a profit center for the manufacturer, they should be avoided at almost any cost. Stay with a specialist mark such as REL. All we want is the opportunity to show you why the .1 in 5.1 should be remarkable.