Rockford Fosgate p3d4-15 Subwoofer Review


When you purchase a 15-inch subwoofer, you’re looking for power. When you want your neighbors to file noise complaints, this is the subwoofer to choose. In this Rockford Fosgate p3d4-15 review, we’ll cover the technology that makes this subwoofer so effective – and so large!

I’ve spent hours devouring technical specs for this subwoofer. I’ve applied research about this model to my own real-life experiences with car audio. For over a decade, I’ve been dedicated to building the perfect car audio system. And I’m here to tell you that this 15-inch subwoofer is the real deal. 

You’ll be able to feel and hear the difference with this subwoofer immediately. Don’t settle for a sub that barely moves the dice on your rear-view mirror. Choose the raw power and deep punch of the Rockford Fosgate p3d4-15.

Highly Recomended
A 15-inch subwoofer with explosive bass and some impressive safety technologies
  • Anodized Aluminum Coil Former
  • VAST Surround Technology allows your cone to move up to 25% more in any direction.
  • Stitched Tinsel Leads distribute load evenly to reduce potential damage.

Rockford Fosgate p3d4-15 – Raw Power in a Huge Package

If you know anything about car audio, you’ve probably heard of Rockford Fosgate products. A recent return from devastating quality concerns has given rise to promising high-performance subs, amplifiers, and speakers. Simply put, Rockford Fosgate came back from the dead to deliver a stunning, industry-leading standard. 

The p3d4-15 model is part of the ‘Punch’ series of subwoofers, and the P3 models are the best of the best. P3 models include overheating protections, including superior venting and other features. It’s almost impossible to get these subwoofers to overheat, though you certainly wouldn’t want to try. 

The 15-inch version of this powerful model packs an even greater punch, including extremely punchy bass. It’s a huge subwoofer, but it’s delivering huge, raw power at every turn. Just makes sure you’re using a large enough box!

What I Liked

  • CEA-2031 Compliant. Most subwoofers on the market today will be tested and compared in the same way. If they are CEA-2031 compliant, you can rest assured that they follow standard testing procedures. This means you can compare them against other CEA-2031 compliant speakers and subwoofers for all performance and specification metrics. Just make sure you pair this subwoofer with compliant speakers.
  • FlexFit Basket. The FlexFit basket design uses a slot-mounted frame. This can help you mount the cone exactly the way you want, helping you tune its performance to an amazing degree. If you’ve ever wished your subwoofer was a little less rigid, this might be the one for you. 
  • Aluminum Cone Design. The aluminum cone is somewhat of a sticking point for some people. They argue that the sound comes out ‘tinny’ or overly metallic. Thankfully, a subwoofer usually has low enough bass to avoid hearing this sound quality. The aluminum cone on the Rockford Fosgate p3d4-15 subwoofer allows for heat control, better sound quality, and long-lasting durability.
  • Durability. Every aspect of the p3d4-15 subwoofer is built to last. From the cooling design to the aluminum cone, FlexFit basket, and extremely durable wiring and connections. If you’re kind to your subwoofer, it will last a long time for you.
  • Extremely Hard Punches. Have you ever wanted your bass to hit so hard your teeth rattle? Look no further. The Rockford Fosgate p3d4-15 hit those lows with a raw power you haven’t experienced before. We’re talking noise complaints, rattled windows, and car-shaking beats.
  • Power Handling. The p3d4-15 can handle an amazing amount of power. With 600W RMS and 1200W Peak, this subwoofer can punch those lows consistently without damaging the subwoofer. It’s built to handle constant abuse, as long as you’ve got the power to handle it.
  • Heat Sink Technology. Along with the aluminum cone design, the voice coil formers help to vent heat away from areas where it may be harmful to your other components. The result is a relatively cool voice coil no matter how long you’ve been jamming.

What I Didn’t Like

  • The Price. Rockford Fosgate brings quality to the table, but it’s expensive. You get what you pay for – the punches from this subwoofer absolutely can’t be beaten. However, you’ll pay a hefty price for them, and you might have to save up to get a pair.
  • The Size. Of course, the p3d4-15 is a huge subwoofer. The 15-inch subwoofer is the largest that they offer. However, it seems much larger than other 15-inch subwoofers. The enclosure is going to have to be extremely large, which means these subwoofers aren’t going to fit behind or under seats at all.
  • The Denting Issue. The aluminum cone is great for sound quality and power. However, the aluminum cone is extremely easy to dent. You’ll have to be careful with this subwoofer, as tossing it around can cause dents that can affect sound quality.

Feature #1: Anodized Aluminum Voice Coil Former

A subwoofer’s voice coil helps your sub sound great, so you should treat it right. The Rockford Fosgate p3d4-15 features an aluminum coil former, which leads down from the aluminum cone design. 

We’ve talked a bit about how the aluminum cone helps lead heat away from the voice coils. The voice coil former takes that technology to the next level. These special coil formers include new spider venting, dust caps, and increased durability across the board. 

This special aluminum piece helps keep your voice coils cool even when the bass is pumping, quickly dispersing and venting the heat to keep it away from delicate wiring and components. If you like extended bass sessions, this heat-reducing technology can save your sub and protect your investment.

Feature #2: VAST Surround Technology

The VAST Surround Technology is a cornerstone of Rockford Fosgate’s newer subwoofer lines. You aren’t going to find it in subwoofers from any other brand. 

This technology changes the way that the aluminum cone attaches to the FlexFix basket. This means that the cone has more room to move. With any subwoofer, a larger area means better performance overall. 

VAST stands for Vertical Attach Surround Technique. In layman’s terms, this allows the cone to radiate up to 25% further. The result? Greater sound clarity, better overall performance, and of course, deeper bass. 

Feature #3: Stitched Tinsel Leads

The leads and wiring in your subwoofer are extremely important. When you’re wiring a subwoofer into your car’s audio system, it has the potential to ruin your car’s electrical system at large. You have to choose one that can stand up to the pressure. 

The Rockford Fosgate p3d4-15 includes stitched tinsel leads. These are strong, reinforced leads that help keep your subwoofer from stressing out. They distribute power and draw equally across the wires, helping to reduce subwoofer fatigue. Your subwoofer is much less likely to short due to these improved leads. 

The p3d4-15 packs so much power that these leads are essential. These reliable wires can extend the life of your high-powered subwoofer. 

Overheating Protection

While the overheating protection on the Rockford Fosgate p3d4-15 isn’t the main feature, it’s may change your entire outlook on this subwoofer. You might think that an aluminum cone may cause overheating. Usually, this is the case.

However, the p3d4-15 (and all P3 series subwoofers from Rockford Fosgate) have a technologically advanced heat sink cone that allows the heat to funnel away from the voice coils. Combined with advanced venting, the voice coil should never get warm. 

If the voice coil never overheats, your subwoofer will last longer. That’s a great design choice for a quality subwoofer.


Let’s look at the Rockford Fosgate p3d4-15 specs, so you know what to expect from this subwoofer.

Power600W RMS, 1200W Max
Speaker ConnectorDual 10 AWG Compression
Nominal ImpedanceDual 4-Ohm
Sound Pressure Level86 dB
Frequency Response22 – 250 Hz
Dimensions18 x 18 x 11.5”
Top Mount Depth7 11/16”
Cone MaterialAnodized Aluminum
Coil TypeDual Voice Coil
Displacement 0.107 cu. Ft.
Magnet Weight90 oz
Net Weight23.8 lbs

But what do these specs mean for you?


Subwoofers have two different power ratings, but both are important. The RMS watts power rating will tell you how much the subwoofer can handle continuously and regularly. The Max power rating, on the other hand, represents how much the subwoofer can handle in short, controlled bursts.

Always assume that the subwoofer will be operating at RMS watts – this is the best measure of its ability. 600 Watts RMS is very powerful for a subwoofer of this size.

Speaker Connector

This subwoofer uses a Dual 10 AWG Compression speaker connector. This means that it can only connect to speakers using this type of connection. Make sure that the Rockford Fosgate p3d4-15 is compatible with your speakers before purchasing.


A larger subwoofer means more powerful bass, clearer highs, and deeper lows. A 15-inch subwoofer is the largest you can find on the standard market. The sound quality might lack a little due to the higher vibrations required to hit those deep bass notes, but nothing booms like a 15-inch subwoofer.

Nominal Impedance

Nominal impedance refers to the amount of resistance running along the audio line. The 4-Ohm nominal impedance level suggests that 4 Ohms is the most resistance you can expect out of the subwoofer, and the sound will adjust accordingly. 4 Ohms works well for subwoofers of this size, as it offers less resistance than a compressed 16 Ohm sub would. 

Sound Pressure Level

Sound pressure level measures the intensity of the sound waves the subwoofer can produce. The 86 dB offered by the Rockford Fosgate p3d4-15 is at the higher range of our hearing threshold and is comparable to the sound pressure level of a busy freeway. This is great for hitting those deeper bass frequencies and making you feel the bass.

Frequency Response

Frequency response is a measure of how well your subwoofer can reproduce sounds within your music. The Rockford Fosgate p3d4-15 can faithfully reproduce frequencies between 22 and 250 Hz. High frequencies within your music may not be produced without distortion, but that’s due to the focus on bass reproduction within this subwoofer.


You’ll need to know how big the subwoofer is so you can plan an enclosure. You’ll also need to place the subwoofer in your car, so knowing how big it is on all sides is beneficial. This subwoofer is massive 15” in diameter. The dimensions reflect how large this sub is.

Top Mount Depth

Your subwoofer’s top-mount depth gives you some idea of how deep an enclosure would need to be. As stated, the Rockford Fosgate p3d4-15 is large, with a top mounting depth of over 7 inches. Turns out that this is a great size for your trunk.

Cone Material

The Rockford Fosgate p3d4-15 ‘cone’ is made of anodized aluminum. This means that it is durable but prone to denting. The rigid material sometimes produces a ‘tinny’ sound, but there is a chance you won’t hear it at all when listening to those low-base notes. It’s a good, durable material for a subwoofer.

Coil Type

This subwoofer uses a dual voice coil. This means that you can wire your coils in parallel, in a series, or independently. You can hook this subwoofer into your system however you choose, making it perfect for custom systems. 


At 0.107 cubic feet, the p3d4-15 has an exceptionally large displacement. Displacement refers to the amount of air left inside the enclosure. Because the cone needs air to produce sound, displacement can tell you how large you need to make your box to accommodate it. Of course, due to its larger size, this displacement will require a large box.

Magnet Weight

The weight of the magnet inside the subwoofer can help you determine how much power it will have. This 15-inch subwoofer has a rather large magnet, making it perfect for handling the large power rating that the p3d4-15 boasts. 

Net Weight

The net weight of the subwoofer can help you determine where to place the sub enclosure, how big it needs to be, and more. This massive subwoofer is about 23 pounds, so it will need a safer space – which makes it good for your trunk.

What The Customers Are Saying 

Overall, customers are reacting positively to the Rockford Fosgate p3d4-15 subwoofer. There are very few negative experiences. Most negative reviews seem to be the result of misuse of the subwoofer, usually by trying to subject the sub to more power than its 600W RMS rating. 

Customers are praising the durability of this model. Most are impressed by how hard the bass punches, with some even saying that they were afraid their windows might break from the vibration. The only complaint among these customers is the price.

For a more in-depth opinion, check out this Rockford Fosgate p3d4-15 subwoofer video review.


The Rockford Fosgate p3d4 15-inch subwoofer is the largest in the P3 ‘Punch’ line, and it’s massive. However, it hits hard enough to make your teeth rattle and has a ton of great features, including an aluminum cone, more durable leads, and intuitive heat sink technologies. 

Highly Recomended
A 15-inch subwoofer with explosive bass and some impressive safety technologies
  • Anodized Aluminum Coil Former
  • VAST Surround Technology allows your cone to move up to 25% more in any direction.
  • Stitched Tinsel Leads distribute load evenly to reduce potential damage.

It is expensive but exceeds expectations. If you are looking for a subwoofer with comparable specs on a budget, consider the Planet Audio AC15D Subwoofer

Rockford Fosgate p3d4-15 Subwoofer Review
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Rockford Fosgate p3d4-15 Subwoofer Review

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