Polk Audio was one of the pioneers in the outdoor custom-install (CI) speaker category, launching its first Atrium outdoor speakers back in 1991 and setting a benchmark for design and performance. Today, however, the outdoor speaker market has evolved dramatically, with dozens of manufacturers competing across every price point—from entry-level to high-end marine and outdoor CI solutions—making Polk’s legacy a tough act to follow in a crowded, fast-paced industry.
Introducing the Latest Generation of Polk Audio Atrium Series Outdoor Speakers
The latest generation of Polk Audio Atrium Series outdoor speakers is designed to meet today’s demanding performance and installation needs. With a focus on delivering quality sound across a variety of outdoor and transitional spaces—including porches, sunrooms, and decks—the refreshed Atrium lineup offers enhanced sonic performance, improved weather resistance, and versatile mounting options. Choose from four models labeled Atrium 4, Atrium 5, Atrium 6 and Atrium 8SDI, priced from $225 to $550 per pair.
Polk Audio’s mission with this update is to provide affordable, reliable, high-quality audio solutions that blend seamlessly into outdoor environments while standing up to the elements and evolving customer expectations. There are 4 models in Polk’s outdoor Atrium speaker line, labeled Atrium 4, Atrium 5, Atrium 6 and Atrium 8SDI.
Polk Audio Atrium Series Key Features and Benefits
- Speed-Lock Mounting System (New): Enables easy, secure one-handed installations even in hard-to-reach locations. The simplified mounting process uses fewer parts, reducing installation hassle.
- Anodized Aluminum Tweeter Domes With Rubber Surrounds (New): Provides clearer, more stable high-frequency response that can often be lost in outdoor environments.
- Injection Molded Mid-Range Cones With Rubber Surrounds (New): Made from mineral-filled or aerated polypropylene—the same materials used in Polk’s high-end LSi Series—redesigned for improved outdoor efficiency.
- Broad Coverage Baffle Design (New): Offers better sound dispersion compared to previous Atrium models.
- Aluminum Grilles and Bracket: Combined with stainless steel and brass components, these materials eliminate rust issues, ensuring longer speaker life in outdoor conditions.
- Polk Audio All-Weather Certified: Exceeds industry and military environmental standards (ASTM D5894-UV Salt Fog, Mil Standard 810 Immersion, Mil-Std 883 Method 1009.8 for salt and corrosion), providing durability and reliable performance for outdoor use.
- Patented Water-Resistant PowerPort Bass Venting: Available on the Atrium 6, Atrium 7, and Atrium 8SDI models, this feature boosts bass output by approximately 3dB for more realistic, musical low-end.
- Patented Dynamic Balance and Klippel Optimization Technologies: Enhances driver and tweeter material performance to minimize distortion and artifacts, delivering more accurate and natural sound reproduction at all volume levels.
Polk Audio Atrium Speaker Series Lineup Comparison — Features and Performance Overview
| Atrium 4 | Atrium 5 | Atrium 6 | Atrium 8SDI | |
| Product Type | Outdoor Speaker | Outdoor Speaker | Outdoor Speaker | Outdoor Speaker |
| Price | $225/pair | $325/pair | $425/pair | $275/each |
| Driver (Midrange/Woofer) | 4 1/2″ (114mm) Mineral-filled Dynamic Balance polymer cone rubber surround |
5″ (127mm) Mineral-filled Dynamic Balance polymer cone rubber surround |
5 1/4″ (133mm) Dynamic Balance polymer cone rubber surround |
6 1/2″ (165mm) Dual Voice Coil Dynamic Balance aerated polypropylene cone, rubber surround |
| Driver (Tweeter) | 3/4″ (19mm) Anodized aluminum dome tweeter w/ rubber suneodymium motor structure |
3/4″ (19mm) Anodized aluminum dome tweeter w/ rubber surround and neodymium motor structure |
1″ (25mm) Anodized aluminum dome tweeter w/ rubber surround and neodymium motor structure |
Two 1″ (25mm) Anodized aluminum dome tweeter w/ rubber surround and neodymium motor structure |
| Frequency Response | 75Hz – 25kHz | 60Hz – 25kHz | 50Hz – 27kHz | 45Hz – 27kHz |
| Recommended Amplifier Power | 10-80W continuous | 10-100W continuous | 10-100W continuous | 10-125W x 2 continuous |
| Impedance | 8 ohm compatible | 8 ohm compatible | 8 ohm compatible | 8 ohm compatible |
| Efficiency aka Sensitivity (dB 1w/1m) | 89 dB | 90 dB | 90 dB | 91 db |
| EnvironmentalStandards | ASTM D5894-UV Salt Fog
Mil Standard Mil-Std 883 Method 1009.8 for salt and corrosion Polk Audio Certification |
ASTM D5894-UV Salt.Fog
Mil Standard 810Immersion Mil-Std 883 Method 1009.8 for salt and corrosion Polk Audio Certification |
ASTM D5894-UV Salt Fog
Mil Standard 810 Immersion Mil-Std 883 Method 1009.8 for salt and corrosion Polk Audio Certification |
ASTM D5894-UV Salt Fog
Mil Standard 810 Immersion Mil-Std 883 Method 1009.8 for salt and corrosion Polk Audio Certification |
| Cabinet material | Mineral filled polypropylene | Mineral filled polypropylene | Mineral filled polypropylene | Mineral filled polypropylene |
| Grille & Bracket material | powder coated aluminum | powder coated aluminum | powder coated aluminum | powder coated aluminum |
| Hardware | Brass or stainless steel | Brass or stainless steel | Brass or stainless steel | Brass or stainless steel |
| Connection Terminals | Gold-plated 5-way binding posts | Gold-plated 5-way binding posts | Gold-plated 5-way binding posts | Gold-plated 5-way binding posts |
| Mounting Options | 180° Speed-Lock™ mounting | 180° Speed-Lock™ mounting | 180° Speed-Lock™ mounting | 180° Speed-Lock™ mounting |
| Dimensions (HWD w/ bracket & knobs) | 8 5/8 x 5 11/16 x 6 11/16 -inches
21.9 x 14.4 x 17cm |
10 5/16 x 6 3/4 x 7 3/4-inches
26.2 x 17.1 x 19.7cm |
11 11/16 x 7 11/16 x 8 ¾ inches
29.7 x 19.5 x 22.2cm |
12 7/8 x 8 1/2 x 9 3/16 inches
32.7 x 21.6 x 23.3cm |
| Product Weight (each) | 3.6lbs / 1.63kg | 4.6lbs / 2.09kg | 5.4lbs / 2.45kg | 9.7lbs / 4.4kg |
| Available Finishes | Black & White | Black & White | Black & White | Black & White |
Which Polk Audio Atrium Series Outdoor Speaker is Right For You?
Depending on the size of your installation and listening space, each Atrium model offers a tailored solution.
The Atrium 4 is the most compact and lightweight, making it ideal for smaller spaces. As you move up the lineup, models are designed to accommodate larger installation areas and deliver greater sound coverage.
All Atrium speakers are reasonably priced and sold in pairs, except for the largest model, the Atrium 8SDI, which is priced individually. Its bigger size not only produces the most bass of the range, but it also can provide stereo imaging from a single speaker thanks to its dual tweeter design.
To simplify installation and compatibility, the Atrium series uses standard speaker terminals with an 8-ohm impedance. This means they connect to regular audio gear you may already own such as A/V receivers, integrated amps, or even streaming amplifiers.
For outdoor surround sound setups, multiple pairs of Atrium 4, 5, or 6 speakers can be combined, or you can use five or more Atrium 8SDI units. Polk Audio recommends pairing these with the Atrium SUB100 subwoofer (priced at $499).
Available in weatherproof black and white finishes, the Atrium speakers suit most outdoor placement needs. They are also paintable, allowing customization to match your outdoor décor.
The Bottom Line
The outdoor speaker market is booming as more homeowners seek to enhance their outdoor entertainment—from movie nights to pool and sports parties. Polk’s Atrium Series stands out by delivering sound quality that defies typical outdoor speaker expectations, elevating the entire listening experience with advanced driver materials, improved weatherproofing, and versatile mounting options.
In a crowded market filled with choices at every price point, Atrium strikes a balance between performance and affordability, making it a compelling option for those who want reliable, quality sound without breaking the bank. However, when considering these speakers, remember that amplification and source components play a critical role in your setup—matching your desired sound quality with your budget is key to unlocking their full potential.
