Don't let limited installation space limit your bass. The Sundown Audio Horizon HZS 10 was engineered specifically for enthusiasts who need serious low-frequency performance in shallow mounting locations without sacrificing the reliability and output that Sundown Audio is known for.

Rated at 600 Watts RMS, the HZS 10 combines a new cast aluminum basket, 2.5-inch black aluminum voice coil, high-roll surround, and vented motor design into a compact package capable of producing clean, controlled bass in truck boxes, under-seat enclosures, stealth installations, and other space-restricted applications.

Whether you're upgrading a daily driver or building a premium custom system, the HZS Series delivers authentic Sundown performance where traditional subwoofers simply won't fit.

Why You'll Love It

✔ 600 Watts RMS Continuous Power Handling

✔ New Heavy-Duty Cast Basket Design

✔ Dual 4 Ohm Voice Coils

✔ Designed Specifically for Shallow Installations

✔ Excellent Performance in Compact Sealed or Ported Enclosures

✔ High-Roll Surround for Increased Linear Excursion

✔ Progressive Spider Suspension for Superior Control

✔ Vented Motor Assembly for Improved Cooling & Reliability

✔ Built to Handle Real Daily Use

Perfect For

• Behind Truck Seat Enclosures

• Under Seat Truck Boxes

• Space-Limited Installations

• Stealth Audio Systems

• Daily Driver Bass Systems

• Compact SUVs

• High-Performance Shallow Subwoofer Builds

Product Overview

The Horizon HZS Series was designed from the ground up to solve one of the biggest challenges in mobile audio: delivering real bass performance where installation depth is limited.

Rather than compromising performance for convenience, Sundown Audio engineered the HZS using many of the same design philosophies found in their larger subwoofers. The result is a shallow-mount subwoofer capable of producing impressive low-frequency output while maintaining the durability and thermal performance enthusiasts expect from the Sundown name.

The new cast basket version further improves rigidity and structural strength, helping reduce unwanted resonance while providing a more stable platform for the moving assembly. Combined with a vented motor, progressive spider, stitched mini-XL tinsel leads, and a robust 2.5-inch aluminum voice coil, the HZS is built to deliver consistent performance through years of daily use.

While optimized for compact ported enclosures, the HZS also performs exceptionally well in properly designed sealed enclosures, making it an excellent solution for trucks, Jeeps, SUVs, and other vehicles where preserving cargo space is just as important as achieving impressive bass.

Ideal Applications

The Sundown Audio HZS 10 is best suited for customers who want strong, musical bass without giving up valuable interior space.

It pairs especially well with:

• Single subwoofer truck builds

• Under-seat enclosure systems

• Behind-seat pickup truck installations

• Daily-driver SQL (Sound Quality + Loudness) systems

• Compact custom enclosures

• Factory cargo area upgrades

Its efficient shallow-mount design allows installers to build systems that maintain usable storage space while still delivering the deep, controlled bass expected from a premium Sundown Audio subwoofer.

Key Features

• 10-Inch Shallow Mount Subwoofer
• New Cast Basket Design
• 600 Watts RMS Power Handling
• Dual 4 Ohm Voice Coils
• 2.5-Inch Black Aluminum Voice Coil
• Vented Motor Gap
• Solid Pole Piece Cooling
• High-Roll Foam Surround
• Progressive Spider Suspension
• Stitched Mini-XL Tinsel Leads
• Bolt-Through Motor Assembly
• Optimized for Compact Enclosures
• Designed for Daily High-Performance Use

Technical Specifications

Brand: Sundown Audio

Series: Horizon HZS

Model: HZS 10

SKU: SW-HZS10D4

Speaker Size: 10"

Subwoofer Type: Shallow Mount

Power Handling (RMS): 600 Watts

Voice Coil Configuration: Dual 4 Ohm

Voice Coil Diameter: 2.5"

Voice Coil Former: Black Aluminum

Basket: Cast Aluminum (New Version)

Motor Cooling: Vented Motor Gap & Solid Pole Piece

Suspension: Progressive Spider

Surround: High-Roll Foam

Lead Wires: Stitched Mini-XL Tinsel Leads

Recommended Sealed Enclosure: 0.50 ft³ Net

Driver Displacement: 0.04 ft³

Mounting Depth: 3.8"

Overall Diameter: 10.8"

Cutout Diameter: 9.4"

Thiele / Small Parameters

Re: 6.850 Ohms

Fs: 44.557 Hz

Vas: 19.254 L

Qes: 0.578

Qms: 3.320

Qts: 0.492

BL: 20.281 N/A

Mms: 124.028 g

Cms: 102.871 µm/N

Sensitivity: 86.6 dB (1W/1M)

Xmax: Not Published by Manufacturer

Enclosure Recommendations

For the best overall performance, Sundown Audio designed the Horizon HZS Series to perform exceptionally well in compact enclosures while maintaining the output and reliability expected from the brand.

Recommended Sealed Enclosure

• Net Air Space: 0.50 ft³
• Driver Displacement: 0.04 ft³

A sealed enclosure provides tight, accurate bass with excellent transient response, making it a great choice for daily drivers and sound quality-focused systems.

Ported Enclosures

The HZS Series was engineered to excel in ported enclosures when maximum output is the goal. While Sundown Audio has not published a recommended ported enclosure volume or tuning frequency for this model, a properly designed custom ported enclosure can significantly increase low-frequency output and efficiency.

If you're planning a custom ported enclosure and would like assistance designing the ideal enclosure for your vehicle and application, our team is happy to help.

Installation Notes

With a mounting depth of only 3.8 inches, the HZS 10 is an excellent solution for installations where traditional subwoofers won't fit.

Popular applications include:

• Behind truck seats
• Under-seat truck enclosures
• Compact SUV installations
• Stealth custom enclosures

For best results, use a high-quality enclosure built to the recommended internal air volume and power the HZS with a quality amplifier capable of delivering approximately 600 Watts RMS at the final wired impedance.

Pro Audio Center Tip

If you're limited on space but refuse to compromise on bass quality, this is exactly the type of subwoofer we recommend.

Build Your System

Complete your bass upgrade with:

• Monoblock amplifier rated around 600 Watts RMS
• OFC amplifier wiring kit
• High-quality RCA cables
• Sound deadening material
• AGM battery upgrade (recommended for larger systems)
• Custom sealed or ported enclosure
• Bass remote level control (when supported by your amplifier)

Expert Recommendation from Pro Audio Center

The Horizon HZS 10 is one of those products that fills a gap many manufacturers struggle to address. Instead of asking customers to sacrifice bass performance for a shallow mounting depth, Sundown Audio engineered a subwoofer that delivers both.

We especially recommend the HZS 10 for pickup trucks and SUVs where preserving usable interior space is important. The new cast basket design adds rigidity and durability, while the 600 Watt RMS power handling provides plenty of output for an impressive daily driver system.

Pair it with a quality 600 Watt RMS monoblock amplifier and a properly built enclosure, and you'll have a system that performs far beyond what most people expect from a shallow mount subwoofer.

Why Buy From Pro Audio Center?

At Pro Audio Center, we don't believe in simply selling equipment—we believe in helping customers build systems that perform exactly the way they expect.

Every product we offer is carefully selected based on real-world performance, reliability, and value. Whether you're building a compact truck system, upgrading your Jeep, or designing a custom audio installation, we're here to help you choose equipment that works together and delivers outstanding results.

When you shop with Pro Audio Center, you're buying from enthusiasts and installers who understand what it takes to build a great sounding system.

Frequently Asked Questions

Is the HZS 10 a true shallow mount subwoofer?

Yes. The Horizon HZS Series was purpose-built for shallow mounting applications while maintaining the performance and durability Sundown Audio is known for.

How much power does the HZS 10 handle?

The HZS 10 is rated to handle 600 Watts RMS continuous power.

What amplifier pairs well with this subwoofer?

For the best balance of performance and reliability, we recommend a quality monoblock amplifier capable of delivering approximately 600 Watts RMS at the final impedance of your system.

Is this subwoofer better in a sealed or ported enclosure?

The HZS performs well in both enclosure types. A sealed enclosure offers tight, accurate bass in a compact footprint, while a properly designed ported enclosure can provide increased low-frequency output and efficiency.

Will this fit under the seat of my truck?

In many applications, yes. With a mounting depth of only 3.8 inches, the HZS is specifically designed for installations where traditional subwoofers won't fit. We always recommend verifying available mounting depth before purchasing.

What makes the new cast basket version better?

The updated cast aluminum basket provides increased structural rigidity compared to stamped designs, helping reduce unwanted flex and creating a stronger foundation for the moving assembly during high-output operation.

Is this a good subwoofer for daily listening?

Absolutely. The HZS was engineered for reliable everyday performance while still delivering the powerful, musical bass that has made Sundown Audio one of the most respected names in car audio.