outdoor speaker – Polk Audio Atrium 45

Polk Audio has a variety of high-quality audio products. A number of their external audio systems have made it into our review. The Polk Audio Atrium 45, however, is the least impressive outdoor loudspeaker we reviewed. It has a small frequency response range and a low sensitivity rating. While the Atrium 45 isn’t as impressive as other outdoor speakers, it is still one of the 10 best exterior audio system options.


The Atrium 45 is designed for the outdoors. Polk Audio made sure this product met or exceeded multiple military-grade waterproofing specifications. This means that it will have no problem handling the elements in your backyard. It is also resistant to rust and corrosion. While they can be used indoors, these all-weather loudspeakers were made to be outside. However, always be sure to point outdoor speakers downward to enable proper drainage during a rain storm.

While the rugged exterior is impressive for an outdoor speaker, the interior is only ordinary. The soft dome tweeter measures 0.75 inches in diameter and includes a neodymium magnet. This powerful magnet allows for quick vibration, and the flexible diaphragm on the driver gives the audio a natural sound. The woofer is made with a mineral-filled polymer to give it a rigid quality. This 4.5-inch midrange driver has rubber surround, which is more durable than foam surround. It is also constructed using Polk Audio’s Dynamic Balance technology, which uses laser precision for better balance and sound.

The sensitivity rating measures how effectively audio devices can convert wattage into volume. The higher the number, the less energy the drivers require to produce a given volume level. A difference of 3dB, for example, means that one product uses half as much energy as the other one. The Atrium 45 outdoor speaker has a sensitivity of 86dB. This is one of the lowest sensitivity ratings in our review. More energy has to be pumped into this loudspeaker in order to get the same volume level as another product like the Polk Audio Atrium 55.

The human ear can hear frequencies from 20Hz to 20kHz. Frequency response is a measurement of the range of frequencies a device like an outdoor speaker can reproduce. The Polk Audio Atrium 45 has a frequency response of 75Hz to 20kHz. This is one of the narrowest frequency ranges in our review. This lack of low bass tones may cause the audio to sound thin in the open air. It also is unable to reproduce supersonic frequencies that are sometimes added in audio mixes to enrich the listening experience.

Since Polk Audio has a number of quality products in this review, it is surprising that this one ranked so low. However, the limited frequency response combined with the low sensitivity means that this outdoor speaker cannot give the full, rich audio offered by other models. It is able to withstand the elements, but it may not be able to withstand a discerning ear. However, despite its low ranking, the Polk Audio Atrium 45 is still a viable outdoor speaker option for your entertainment.