MTX square subwoofers are the evolution of square subwoofers.  ThunderSquare85 series subwoofers are designed to deliver exceptional SPL to enthusiasts that are looking to get maximum bass out of their system.  ThunderSquare85 subwoofers feature a patented surround design that increases the amount of cone surface diameter and that allows for exceptional excursion which results in unbeatable volume displacement (boom, for those of you not familiar with volume displacement), almost 25% more than the leading competitor.  TS85 subwoofers feature an anodized aluminum dustcap and cast aluminum basket that increase efficiency and reduce resonance maximizing dB's and sound quality.