Monoprice has another hit on their hands, the Monolith 13 is an absolute gem. When I tested the sealed M15-S a few years ago I concluded “the Monoprice Monolith M15-S is a winner” and I have no intention of backing off that now, the company has struck gold again. I really like this subwoofer, it delivers the goods no matter what you throw at it. Monoprice is clearly on a roll, the team behind the Monolith line deserves a raise for a job well done (did I say that before?).

This subwoofer is a beast. A costly beast. But, a beast nonetheless.

Monolith by Monoprice's 13THX is huge, heavy, and lacks the convenience of app-controlled on-board automated EQ and curve-selection. But if you have more-than-generous space and budget, it's all the subwoofer you or anyone else will ever need.

I can't help but evaluate the Monolith 13" in light of the Monolith 15". They do have a lot in common. Similar build attributes, similar performance targets, and some aesthetic similarities. But the Monolith 13" kicks everything up a notch. It's a significantly better subwoofer for a few hundred dollars more. In my opinion, it scales well in improvements for the added cost. You get double the amplification, a beefier driver, and a nicer-looking subwoofer. It's like a deluxe version of the Monolith 15" in that it keeps the same basic design and size but improves every other aspect including performance.