Polk Audio UltraFocus 8000 noise-canceling headphones review
Innovative extras give these headphones an advantage
Ralph Graves is one of Crutchfield's blog editors, and part of the company's social media team. He writes about home audio/video gear, specializing in Apple-related and wireless technologies. Ralph holds a master's degree in music composition, and his works have been released on various labels. He's served as product manager for an independent classical and world music label, produced several recordings, and worked extensively in public broadcasting. Since 1984 he's hosted a weekly classical music program on WTJU, and is also active as a blogger and podcaster.
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I always like to try out noise-cancellation headphones in the office. Although our floor isn't that noisy, there are some constant sounds that it’s always a relief to get away from. As expected, when I donned the Polk Audio UltraFocus 8000 noise-canceling heaphones, the rumble of the HVAC and the murmur of conversations in other cubes vanished.
Nice as the experience was, this review wouldn’t be very helpful if that was the extent of my experience.
Noise cancelation basics
The UltraFocus 8000s use some sophisticated circuitry that goes a little beyond the standard noise canelation process. Noise cancelation headphones in general rely on the same acoustics. A sound wave, and a matching one 180 degrees out of phase, will interfere and negate each other. The overall effect is that the two waves silence each other.
The technology to do this is pretty standard. Microphones on the surface of the earcups pick up ambient sound. Circuitry in the headphones process it, and sends the out-of-phase version into the earcups, where it cancels out the ambient sound that manages to leak through.
Of course, it takes a little time for the signal to be processed, so the out-of-phase version is always a fraction of a second behind the ambient sound. Usually most of the sound is canceled out, but not all. This was the case with the Polks. Constant background noise, such as the rumble of the HVAC, virtually disappeared. Because there was little variance between what was leaking through and the processed signal, the cancelation was effectively instantaneous. Irregular sounds, such as conversations, laughter, etc. were significantly dulled (that lag is very short), but it was still present.
Noise cancellation plus
A little extra built into the circuitry of the UltraFocus 8000s gave me a pleasant surprise. The headphones delivered better sound quality than I had expected. Usually the music coming through noise-canceling headphones seems a little muted to me.
Some of the frequencies in the music (which is the signal I want to listen to) are also present in the ambient sound (which is the signal I don’t want listen to). When the out-of-phase signal comes through the headphone drivers, it can also cancel out those shared frequencies, which can give the music a slightly unfocused sound.
Polk gave their processors the additional task of looking at those frequency overlaps and ensuring the ones in the music are still present. It makes sense on paper, but more importantly, it made sense to my ears.
In other words, It worked.
As always, I made sure to audition many different types of music to hear the effects on not just what I like to listen to, but what others do as well. Rock, hip hop, electronica, country, world music, and other genres — they all sounded detailed and focused.
Acoustic genres such as bluegrass, folk music and jazz fared the best. My classical selections — especially chamber music and instrumental soloists -— sounded just as they do when I listen through a comparable set of standard over-the-ear headphones.
Talking up a storm
Having all that office chatter shoved into the background is great — but sometimes I have to participate in it, too. A built-in talk button let me field an occasional question without having to remove the headphones. It’s a convenient feature for travel, too — such as replying to a flight attendant without removing your headphones, or answering a question from your travel companion.
The talk button is set into the right earcup, along with volume control, and play/pause. It mutes your music and switches the incoming signal to the external mics. It’s nothing new, but the UltraFocus 8000s add a nice little innovation. The button doesn't just switch to input from the external mics. Instead, the processors open up a window in the freqency range of the human voice. Within that range, the sound comes through in phase. On either side of that range, the sound continues to be out-of-phase. The end result is that ambient sounds (especially HVAC whirs and jet engine drones) continue to be minimized, while the speaker’s voice comes through clearly.
|The Polk Audio UltraFocus 8000s fold flat to fit into their included travel case.|
Taking it to the Crutchfield Labs
Of course, our HVAC unit didn't provide a big challenge to the noise-canceling abilities of the UltraFocus 8000s, so I also tried out these headphones in the Crutchfield Labs. In the Labs’ sound-proofed home theater room we have the ability to pipe in recordings of lawn tractors, noisy offices, and inflight airline cabin noise. It’s the same audio test we used in our recent noise-canceling headphones challenge.
I chose a cabin noise recording to play through the home theater system and put on the headphones. As expected, they did a good job keeping the jet engine roar to a minimum.
I pushed the test further and further by continuing to crank the volume of the system. With the home theater receiver volume set at -12 dB, the noise was at a comfortable listening level (even if the actual sound was irritating). At 0 dB, the UltraFocus 8000s continued to keep the roar far in the background.
I cranked the receiver volume to its max, +18.75dB. At that level, it was very uncomfortable for me to be in the room without headphones of some kind. The sound was too loud, and I could feel my ribcage vibrating to the rumble of the low end. When I put the UltraFocus 8000s on, the noise became bearable in the small room (although to preserve my hearing I didn’t leave the volume that high for more than 30 seconds). An extreme test, granted, but one I felt the headphones passed.
Recommended for travel (and office travails)
As with other headphones I’ve auditioned in the office, I wore the UltraFocus 8000s for long periods of time — three to four hours at a stretch over the course of several days. They sat lightly on my head, and were extremely comfortable the entire time — an important consideration if you're going to be taking these along on a trans-continental flight! The earcups completely covered my ears, providing an effective acoustic seal.
The headphones’ noise cancelation technology worked well, and the benefits of the extra processing features Polk built in were noticeable and appreciated. Whether you’re flying across the country or just being a desk-jockey all day, the Polk Audio UltraFocus 8000 noise-canceling headphones can make the experience not just bearable, but enjoyable as well.