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4 Thunderous Powered Car Subwoofers Under $300

An SUV with a subwoofer in the open trunk, and speakers on the opened passenger's side door.

If you’re looking to add a little more bass (no treble) to your car’s sound system, a good subwoofer is the way to do it. These combos can add some thunder without pounding your wallet.

What to Look for in a Powered Subwoofer System

Twenty years ago, if you wanted powerful bass for your car audio, you had to spend north of $1,000 to get a decent system. Thankfully, times have changed. You can get a great-sounding powered subwoofer package for less than $300! While you might not win any audio competitions with them, these inexpensive systems are an easy bolt-on to enhance the rumble of a factory car stereo or custom aftermarket sound system.

Here are some important factors to consider when you purchase a powered subwoofer for your vehicle:

  • Enclosure size and form factor: It’s easy to get an inexpensive, decent-sounding system. It’s not as easy to find one that sounds great and fits well in your vehicle.
  • Power: Subwoofer and amplifier power is best measured by Root Mean Squared (RMS) watts. RMS watts is the continuous power handling level into a given speaker resistance with a Total Harmonic Distortion (THD) of 1 percent or less. So, you’re looking for how much power the subwoofer/amp can handle continuously without sounding like garbage.
  • Frequency response: In most cases, larger woofers generate more volume and lower frequencies (deeper sound). But don’t get trapped by the bigger-is-better concept—that’s not always the case. There are some great 10-inch, eight-inch, and (surprisingly) six-inch subwoofers out there that generate a low, tight rumble.
  • Signal input options: Most powered subs support a line-level input from a subwoofer pre-output on a stereo head unit. But most factory stereos don’t provide subwoofer pre-outputs. Some subwoofers also support high-level inputs, which allow you to tap into the front or rear speaker wires directly to get the audio signal. The good news is this “tap” doesn’t actually have to drive the subwoofer; it just provides the sound stream to the subwoofer. It doesn’t affect the volume or quality of sound for the source speaker channel.

The key to adding good bass is to match the right size, power, and frequency response to the cabin volume of your vehicle. Larger interior spaces require more power, but also typically have more space for a larger system. A smaller interior often doesn’t require as much speaker size or power to achieve good bass. In a smaller car, you can get away with less power, and a smaller speaker size and installation footprint.

Best Overall: Rockville RWS12CA Slim 1200 Watt 12-inch Subwoofer

The Rockville RWS12CA subwoofer and remote.

The Rockville RWS12CA combines a slim subwoofer box with a built-in monoblock amplifier and a 12-inch, shallow mount subwoofer. This system measures 24 inches (length) x 15 inches (height) x 4.37 inches (top depth) x 6.65 inches (bottom depth). It pushes 300 watts (RMS) and 1,200 watts (peak). The RWS12CA delivers powerful, cabin-filling bass in a form factor that’s easy to install, at a price point you won’t believe. The enclosure will fit under most rear crew-cab seats in a full-size truck. You could also easily stow it in the trunk of a car or the rear hauling space of an SUV.

The RWS12CA plays nice, with an aftermarket head unit that provides a line-level sound source and remote turn-on signal. You can also tap into high-level speaker lines to add it to a factory system. With an Auto Start Music Sense, the amplifier detects when the high-level speaker source provides a signal and turns on the amp power. A configurable low-pass crossover, +12 dB bass boost, and remote bass control are also included.

If you already have sub-wiring in place, you can knock $10 off the combo price. Otherwise, the Rockville RWS12CA + Wire Kit is the better value.

Best Overall

SEYOO Headphone for Men,Sky-Blue

The quality of the Rockville RWS12CA's deep, cabin-filling bass is matched by the configuration options of the amp. This, combined with the slim enclosure for installation flexibility, makes this our pick for Best Overall.

Best Bang for the Buck: MTX Terminator Dual 12-inch Powered Subwoofer

MTX Terminator subwoofer and TNA251 monoblock amplifier.
MTX Audio

If you have plenty of available space—and a desire for real thunder without thumping your bank account—the MTX Terminator Dual 12-inch powered subwoofer box is the way to go. The two subwoofers in this system can handle 200 watts RMS each, for a total of 400 watts (RMS) and 800 watts (peak). It ships with an MTX TNA251 monoblock amplifier that’s specifically matched to the subs. The subs are mounted in a sealed, 5/8-inch-thick MDF box for tight bass response. However, you’re going to need plenty of room in the trunk or rear cargo area for this beast (it measures 14 inches x 29.625 inches x 13.5 inches).

The TNA251 amplifier is highly configurable and supports both high- and line-level inputs, high- and low-pass filter crossover systems, and remote bass control (not included).

There are certainly more powerful subwoofer systems out there, but power isn’t everything. This rig perfectly matches the sealed enclosure size, dual 12-inch subs, and amplifier to produce thunderous bass you won’t find elsewhere at this price.

Best Bang for the Buck

MTX Audio TNP212D2 Terminator Power Pack Subwoofer System - Set of 2,BLACK

The MTX Terminator Dual 12-inch Subwoofer package perfectly matches the enclosure, subwoofer, and amp specifications. It provides inexpensive, booming bass and earns our Best Bang for the Buck award.

Best Low-Profile Subwoofer: Rockville RW10CA 10-inch 800-watt Subwoofer

The Rockville RW10CA subwoofer.

The Rockville RW10CA will amaze you with the bass it generates from its 12.4-inch (length) x 13.4-inch (width) x 2.7-inch (height) box! This unit will fit behind most standard- or rear-cab truck seats, or even under many vehicle seats. Of course, with the included mounting brackets, you can lock in this sub just about anywhere in rear storage.

But the best part about the RW10CA is how Rockville was able to cram the 10-inch sub and amplifier into that tiny box and still generate so much bass! It pushes 200 watts RMS and 800 watts peak, so you won’t be disappointed with the sound this little box manufactures. It provides an 18-decibel bass boost and low-pass filter, and a remote bass control is included. The RW10CA supports both high- and line-level inputs and has automatic turn-on capabilities.

If you like the RW10CA but have an extra-small vehicle with limited mounting options, check out the Rockville RW8CA 8-inch 600-watt low-profile unit. Its 12.4-inch (length) x 11-inch (width) x 2.7-inch (height) box is 2.4 inches narrower than the RW10CA, so it will fit under even smaller car seats.

Best Low-Profile Subwoofer

Rockville RW10CA 10" 800 Watt Slim Low Profile Active Powered Car Subwoofer Sub, Black

With the RW10CA, Rockville crams a 10-inch subwoofer and amp into a tiny, 2.7-inch-deep box. Its small size, coupled with its surprisingly powerful bass, earns it our Best Low-Profile Subwoofer award.

Best Bass Tube: MTX RT8PT Powered Subwoofer

The MTX RT8PT Bass Tube.
MTX Audio

Bass tube-style subwoofer enclosures are great options for smaller cars that need a little extra low-end punch in a small, easily storable form factor. A bass tube packs well in the trunk or rear storage area, and they typically feature an eight- or six-inch subwoofer. Placement is important—they sound best when they point into a vehicle corner, so they can take full advantage of audio wave reflection.

The MTX RT8PT sports a 120-watt (RMS) onboard amplifier, and an eight-inch high-performance subwoofer in a vented, tube-style enclosure. The RT8PT cranks out far more bass than you’d expect, given its small size. It supports both high- and line-level inputs and provides a low-pass filter, so you can blend the bass output with existing speakers.

The MTX RT8PT enclosure also features a flat bottom and angled subwoofer design to provide stability and maximize sound reflection.

Best Bass Tube

MTX Audio RT8PT Universal Powered Subwoofer Enclosure

The MTX RT8PT bass tube provides industry-leading subwoofer and amp power in an attractive, functional enclosure to take our Best Bass Tube award.

Russ Houberg Russ Houberg
Russ is a 20+ year veteran of the Information Technology industry and has been that "techie" for a multitude of people and organizations over the years. He holds several professional certifications including Microsoft Certified SharePoint Master and Microsoft Certified Solutions Expert. As a published author, he enjoys freelance writing when he has the opportunity.   Read Full Bio »