Best Passive Radiators for Subwoofer [REVIEW]

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The passive radiators for the sub can extract additional power and resonance from a smaller audio system. The term “passive” refers to the fact that they are not electrically powered. Instead, they are powered by the air pressure caused by the smaller speaker cones, which get all of the electrical energy from the AC source or battery.

The Earthquake Sound SLAPS-M12 is the winner of this round-up of the best passive radiator for the sub as it allows you to make quick adjustments with easy tuning, add extra enclosure volume or amp power, add up to 6dB of bass to subs, and add additional mass to make the lower levels listenable. However, the other passive radiators for sub reviewed below all have their own unique selling proposition (USP), which has helped them to make the list.

1-Ohm Subs We Recommend

Our Pick

Earthquake Sound SLAPS-M12 12-inch Passive Radiator

Size: 12-inch
Tuned to: 25.5Hz

Earthquake Sound SLAPS-M12 is a tunable, 12-inch passive radiator for sub. It is ideal for quick adjustments with easy tuning and can help to terminate wind noise, remove voice leakage, and eliminate offsetting of the voice coil. With this passive radiator, you can add extra enclosure volume or amp power.

You can add up to 6dB of bass using this passive radiator to the line of high-output subs of Earthquake. Moreover, this passive radiator is designed to complement almost every Earthquake sub. Furthermore, thanks to user-adjustable settings, it can be tailored to any vehicle stipulation or musical preference.

The SLAPS-M has an evenly spaced loaded suspension, which means that the force moving the diaphragm outside is similar to the force moving the diaphragm inside, ensuring that the speaker voice coil is ideally aligned while in motion.

When tuned to low frequencies such as 25.5 HZ, traditional port tuned enclosures necessitate ridiculously long ports that seep voices. The SLAPS-M does not need additional volume. Instead, it adds additional mass to make the lower levels listenable. All of these features of the Earthquake Sound SLAPS-M12 make it our top pick amongst all the passive radiators for a sub that is reviewed here.

Runner Up

Kicker 47KBRW12 Tuned Passive Radiator

Size: 12-inch
Tuned to: 34 Hz

Ports necessitate larger enclosures to function properly and can occasionally generate unwanted noise. Kicker’s 47KBRW12 12″ passive radiator, when paired with a suitable 12″ subwoofer, delivers the zing of a ported box in a tiny enclosure that is sealed and that can be accommodated in more places in your car.

It is important to note that this passive radiator will not generate sound on its own. It must be used in conjunction with a subwoofer in an enclosure. Kicker suggests using a sub with a box volume of 0.7 cubic feet, such as the Kicker CompRT subwoofer. This passive radiator for a sub is tuned to 34 Hz for the best results.

The Kicker 47KBRW12 comes with four adhesive-backed screw covers and a one-year warranty to cover you in case the passive radiator starts to malfunction or does not work as advertised. For all of these reasons, the Kicker 47KBRW12 finishes as runner-up to Earthquake Sound SLAPS-M12.

Value for the Money

Dayton Audio DS215-PR 8″

Size: 8-inch
Tuned to: 23.3 Hz

The Dayton DS215-PR 8″ passive radiators are intended to be used in tandem with active speakers with an Xmax movement of less than or equivalent to 9mm and thickness of less than or equivalent to 9mm. They will improve bass response by eliminating the requirement for bass reflex loads.

The passives complement the Shielded DVC line of subs esthetically and functionally, with a medium-roll rubber surround and durable coated paper cone for smooth outing and long life. The applications for these passives are limitless, ranging from floor-standing two-way speakers to small active/passive subsystems.

For lower tuning frequencies such as 23.3 Hz, adding mass is made simple by the M5 threaded hole of this passive radiator. Overall, the Dayton DS215-PR 8″ is a good passive radiator for the majority of sub designs, and owing to its features and the price it comes for, we consider the DS215-PR to be the best “value for money” passive radiator available today.

Dual option

Earthquake Sound Pump Horn-Loaded

Size: 12-inch
Tuned to: 25.5Hz

The Earthquake PUMP-12 combines two horn-loaded 12-inch passive radiators into a single unit. The PUMP-12 allows you to add up to 6dB of bass without any requirement for extra input power. The PUMP-12 passive radiator has a wide range of uses and applications.

The Earthquake PUMP-12 can be accommodated into a sealed enclosure and is suitable for people who need a high output from their subs when space is limited. Finally, the Earthquake PUMP-12 is compatible with subs of all types.

Small size option

AIYIMA 4-Inch Passive Radiator Replacement Kit

Size: 4-inch
Tuned to: Around 70Hz

The passive radiator structure of the AIYIMA allows for deeper bass in a narrower enclosure than traditional enclosure designs. It also enhances the adjustments of deep bass frequencies.

These are excellent passive radiators; they are a little stiff and don’t have a lot of excursions, but they sound fantastic. Their frequencies are tuned to around 70Hz. When the speaker is turned on, it will vibrate up and down. It will generate airflow, and this airflow will push the bass diaphragm, resulting in low frequency.

This radiator allows enhancing speaker bass to its full range and features a bass vibrating membrane. Moreover, it has a hole diameter of 4.65MM, which makes it simple to add mass to lower tuning frequency, just like with DS215-PR.

Overall, this passive radiator for subs or speakers has a good build quality and its compact design makes it perfect for small enclosures.

Last update on 2022-12-01 / Affiliate links / *Image Disclaimer: We use images/data from Amazon Product Advertising API solely on products that link to Amazon. On products with the "Price at Crutchfield" button, we use images/data from Crutchfield.com as per the partnership deal.

Hey, there mobile audio lovers! My name is Vincent Talbot, founder and chief editor at 99carstereo.com. Ask any mobile audio fanatic, installer, or company rep what makes a good car speaker, sub or amp, or, better yet, why he or she prefers a certain brand over another, and be prepared to endure a litany of opinions, viewpoints, and passion-fueled perspectives. To be honest, mobile audio shopping can be a daunting task without a guide, so I’ve assembled what I feel are the best products to consider to make things easier for you. More about me.

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