The Polk Audio Atrium4 outdoor speaker set is smaller than the Polk Audio Atrium 55, but the compact design comes with a compromised performance. This is the lightest model we reviewed, but the frequency response is only average and it isn't able to handle as much power. Nonetheless, this is still one of the top 10 exterior audio systems in our review and it is backed by the trusted name of Polk Audio.
Each outdoor speaker in this pair only weighs 3.6 pounds. This lightweight design makes them easy to mount on your home or patio. However, even though they are very light, you should still make sure to attach them to a solid piece of wood or stone for stability. Polk Audio's Speed-Lock mounting system offers a simple way to adjust the angle of your speakers. Additionally, the outdoor speaker units only measure 9 inches high, 6 inches wide and 7 inches deep. They can be easily hidden away so the audio can seem to come from an unknown source.
The Atrium4 uses a 0.75-inch anodized aluminum dome tweeter and a 4.5-inch mineral-filled polymer cone woofer to produce all the sound. Polk Audio recommends using 10 to 80 watts of power from your amplifier to get the best performance out of these drivers. Anything below 10 watts won't give satisfying audio quality and anything above 80 watts for a sustained amount of time could permanently damage the loudspeakers. This rating of 80 watts is one of the lowest peak powers in our review. It seems these lightweight units aren't able to handle the power that other outdoor speakers can.
The human ear can hear audio frequencies from 20Hz to 20kHz. Many of the outdoor speakers in our review have a bass response of 60Hz, which is acceptable for exterior audio systems. The Polk Audio Atrium4, however, only has a frequency response of 75Hz to 20kHz. This lack of bass tones could cause the audio to have a thin sound in the open air. While they can play everything the human ear can hear, they are unable to play the harmonics and supersonic tones that are included in some music to enhance the listening experience.
This outdoor speaker system is backed up by a large support system. Polk Audio covers this product with a five-year limited warranty. You can also find the manual on the manufacturer's website as well as a FAQs page. If you need additional help, you can contact customer service by email, by telephone or by live chat. Live chat, however, is only available during Polk Audio's business hours.
Even though the Atrium4 has a lightweight and compact design, it also has a very durable exterior. It is certified for all weather conditions and features a polypropylene cabinet, aluminum grilles and stainless steel hardware. However, this rugged exterior is not matched in the interior. The Polk Audio Atrium4 has a low tolerance for wattage and the frequency response is lacking. Nonetheless, this outdoor speaker set will still be able to fill your yard with adequate sound.