Monolith by Monoprice 16″ THX Ultra-Certified Subwoofer – 170lbs of Bass!

Monoprice announced their Monolith 13″ and Monolith 16″ THX Ultra-Certified Subwoofer in August, with the 13″ available at that time. This past week, Monoprice has finally released the 16″ version. The subwoofer features a high excursion, 16″ driver, and a four-port design, and mates it to a 2000W (3800W peak) class D amplifier. Monoprice designed this beast to bring the boom, dropping down 14hz in its vented mode! Designed for larger spaces (3000+ cubic feet), priced at $2299, the Monoprice 16″ THX Ultra-Certified Subwoofer is $600 cheaper than its main competitor, the SVS PB 16-Ultra. It is a beast that will require you to either own a handcart or have access to a couple of friends!

Monoprice 16” Ultra THX Subwoofer Specs

Woofer16″ cone
Cone Material2 layer long fiber pulp/glass fiber cone
Voice Coil100mm with high temperature aluminum wire and black anodized aluminum bobbin
SurroundFEA optimized NBR (nitrile budadiene rubber)
MotorFEA optimized, 2 aluminum shorting rings, undercut T‑pole focused field
MagnetCeramic Y35, 2 pcs total 300 oz.
Xmax28mm (one‑way)
Xmech90mm (peak‑to‑peak)
EnclosureSealed or vented HDF cabinet with horizontal and vertical bracing
FinishBlack Ash
Amplifier2000 watts RMS (>3800 watts peak)
Harmonic Distortion<1% 20~100 Hz (90dB @ 1m)
Variable Level Control+15/‑20dB
REF Level(100mV @ 40Hz): 89dB @ 1m
CrossoverInline/Bypass variable 40~160 Hz
Variable Phase0~180°
InputsRCA (2), XLR
Signal Turn OnSelectable always-on/auto
Auto Turn Off30 minutes
Dimensions25.6″ x 22.0″ x 28.1″ (650 x 560 x 715 mm)
Weight171.6 lbs. (77.8 kg)
Frequency Response (‑6dB)Sealed1 port2 ports3 ports4 ports
     Extended EQN/A17~200 Hz14~200 Hz14~200 Hz16~200 Hz
     THX EQ20~200 Hz17~200 Hz24~200 Hz14~200 Hz16~200 Hz

Back Plate

The Monoprice 16″ THX Ultra-Certified Subwoofer has a 2000W (3800w peak) plate amplifier. It is outfitted with standard gain, phase, and crossover adjustment knobs. It also features both RCA and XLR inputs and a single XLR output for daisy-chaining subwoofers. An always-on/auto-on switch rounds out the available controls. Because of this, it is a pretty versatile setup that lets you connect to pretty much anything on the market.

The backplate of the Monolith by Monoprice 16″ THX Ultra-Certified subwoofer has lots of connection options


So like its little brother, the Monoprice 16″ THX-Certified Ultra Subwoofer features High-Density fiberboard (HDF) construction. Not only is it heavier than MDF, but it also allows for a more rigid frame. This extra weight and rigidity mean that no matter how hard it hits, the only thing rattling will be your teeth, walls, and probably your neighbor’s walls! Weighing in at 176lbs and measuring 26″ x 22″ x 28″ is not a subwoofer you can place yourself. Bring a dolly, or bribe the delivery person to help you bring it into your space.

The fit and finish of the Monoprice 16″ THX-Certified Ultra Subwoofer are superb. It features nicely rounded corners and comes in a painted matte black finish. I wish more speaker companies would offer matte colour options, but I may be in the minority. The four ports are set into the base of the speaker cleanly. There is no hint of a joint anywhere. For me, Aesthetics play a huge part in choosing a speaker. I don’t care how good a speaker performs; if it looks gaudy, I am passing.

Monoprice 16” Ultra THX Subwoofer Performance

The Monoprice 16″ THX Ultra-Certified Subwoofer is a beast. A high excursion 16″ woofer, backed by a 2000w (3800w peak) power supply, means that this thing will hit like a sledgehammer! Monoprice has carefully mated its drivers to the correct power supply to ensure they can get the most out of their driver and enclosure design but maintain accurate bass throughout. So while 2000w may seem like overkill in a home theater setting, in a large room (3000+ cubic feet), this subwoofer needs the power to match the dynamics of movies.

The Monoprice 16″ THX Ultra-Certified subwoofer comes with two preset DSP modes and is not user-configurable. In THX EQ sealed mode, the subwoofer hits 20hz, and in 3 port vented mode, it hits 14hz. In Extended EQ mode, the Monoprice 16″ Ultra THX Subwoofer can hit 17hz in its vented one port mode and dips down to 14hz in three port vented mode. We do like that Monoprice has opted for both THX and THX Ultra certification. Because of this certification, you can rest assured that it will perform to exacting standards. The subwoofer also ships with port plugs, meaning you can dial this sub in to perform best in your space.

Our Take

The Monoprice 16″ THX Ultra-Certified Subwoofer is a lot of subwoofer for its price tag. No, it is not cheap. But at $2299, it’s $600 cheaper than its main rival, the SVS PB 16-Ultra. The SVS can reach a bit lower, has a parametric EQ, has a smartphone app that allows you to control its functions, and has a smaller footprint. But, $600 is a lot of money to leave on the table for marginally better performance and a smartphone app. You’ll have to decide if the extra functionality, convenience, and EQ are worth it.

It’s not hard to recommend the Monoprice 16″ THX Ultra-Certified Subwoofer. If you have the space, the strength, and the funds, it’s a solid performing subwoofer with a reasonable price tag. For more information, visit

2 Comments on Monolith by Monoprice 16″ THX Ultra-Certified Subwoofer – 170lbs of Bass!

  1. Scotty

    I have 2 of this in my house and I can tell you first hand, you should not order 2 of these. ONE is all you will need to destroy anything that’s not bolted down. This thing is a beast, how could you say that the SVS ultra16 has better performance? No way, I’ve listen to both and Monolith is louder, faster and just sounds better than the SVS. Both are great subs, but if you are debating between the 2, Monolith 16 is a sure bet….No gimmicks, apps, or fancy advertising, Its extremely linear and if you have any problems with bass response, Its your room not the sub. Spend the extra money on room treatments or a miniDSP, and thank me later. 🙂

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