Polk UltraFocus 6000 noise-canceling headphones review
Going the extra mile
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.
More from Ralph Graves
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I had an opportunity to try out the Polk Audio UltraFocus™ 6000 in-ear noise-canceling headphones over the weekend. I wasn’t doing any traveling where I could test the noise-canceling capabilities, so I did the next best thing — I hopped on my lawn tractor and spent Saturday mowing our field and listening to music. As expected, the UltraFocus 6000s did a great job minimizing the whine of the lawn tractor.
Noise reduction step 1: Sealing the ears
It's important to remember there are actually two levels of noise reduction going on with a set of in-ear headphones such as the UltraFocus 6000. The first is inherent in the design of the earbuds themselves. By filling the opening of the ear canal, the earbuds physically block out a lot of the ambient noise.
In order to be effective though, that seal has to be as tight as possible. And it needs to be as comfortable as possible, too. If you're going to be wearing them for a long time (like a long plane flight, or mowing a few acres), the earbuds need to rest gently in the ears.
That was no problem with the UltraFocus 6000s. Sometimes I’m presented with just three choices for earbud tips — small, medium, or large. Sometimes one of those sizes fits well, and sometimes not. Polk offered the widest variety of tips that I have seen in a while. I could choose between silicone tips, smooth or ringed rubber tips, or foam tips. And each option had different sizes. I was able to find a set that provided a tight, secure yet comfortable fit.
Noise reduction step 2: electronics
The second line of defense against ambient sound is the noise-canceling circuitry. Active noise-canceling takes place when the ambient noise leaking in is countered by a 180-degree out-of-phase version of the same sound. The two signals effectively cancel each other out, leaving relative silence.
Where does that other signal come from? Microphones built into the earbuds pick up exterior noise which is then processed inside the headphones’ circuitry to create the out-of-phase version. The out-of-phase signal is then fed into the earbuds’ drivers (along with your music).
Sometimes these canceling frequencies are also shared by the music, though. To my ears, it can dull the music and make it seem a little unfocused. Polk’s processing circuitry looks at the frequencies being canceled and makes sure that they’re restored in the music coming through.
It worked pretty well. I listened to a variety of different genres, and they all sounded clear and clean. The soft focus I was used to with these type of headphones just wasn't there.
And as for the noise-cancelation, it worked really well. I still heard the roar of the lawn tractor, but it was so far in the background that it didn't wear on me, and didn’t interfere with my music at all.
An airline trip in the Crutchfield Labs
Yes, there's a big difference between the drone of a jet engine and that of a lawn tractor, so I felt I had to test the UltraFocus 6000s just a little bit more. Although Crutchfield’s headquarters is literally across the street from an airport, brief test flights aren’t in our budget.
But I could do a reasonable simulation of an airline flight in the Crutchfield Labs. We have some recorded inflight cabin sounds we can play through our home theater system. It’s the same basic setup we used in our noise-canceling headpone challenge. I called up one of those recordings and put the UltraFocus 6000 to the test.
The normal listening level for the current home theater setup is with the receiver volume set at -12 dB. At that level, the UltraFocus 6000s really pushed the engine roar to the background. At 0dB, they continued to effectively filter the ambient noise. As with the lawn tractor, the sound was there but very much muted.
I cranked the system all the way up to the max, about +18.75 dB. At that volume level, I could feel the vibrations of the sound on my chest, and it was very uncomfortable to endure in that small, soundproofed room with the headphones off. Although the sound that came through increased, the UltraFocus 6000s still kept a lid on it, keeping the noise from being a painful listening experience.
That was an extreme test, and I'm not recommending using the UltraFocus 6000 for industrial ear protectors, but it's good to know that they can handle far louder ambient sounds than I’m likely to normally encounter.
The UltraFocus 6000s have a talk button, which mutes the music and switches the source to the external microphones. It's a great feature when you're flying and the attendant is taking your drink order. I used it Saturday when my wife came out to tell me not to mow over the hostas again.
A talk button isn’t unique — many companies incorporate something similar into their noise-canceling headphones. The difference was that the UltraFocus 6000s didn't just switch off the noise-canceling feature. Rather, the circuitry created a window in the range of the human voice to come through unprocessed while still generating an out-of-phase signal for the frequencies above and below it.
Normally, I have to stop the mower and pull the earbuds out in order to hear what my wife says. This time, I could press the "talk" button and clearly hear her instructions as I drove by on the mower. The motor whine was still reduced, and the hostas were spared.
One more thing — the headphones use a flat ribbon-style cable that’s billed as “tangle-resistant.” It was! Even after packing the headphones in their travel case a few times, whenever I pulled them out the cable just kind of unfurled, tangle-free.
The extra innovations Polk built in, such as restoring canceled frequencies and the voice range frequency window for talk made a big difference. If you like in-ear headphones, then the Polk UltraFocus 6000s would be a great choice for travel. They're very effective at reducing ambient noise, they come with enough tip choices to ensure they'll fit comfortably in almost any ear canal, and they don't compromise on sound quality.