|
About our testing:
Our testing rig consists of professionally awesome hardware and software. Our hardware is a head and torso simulator, HATS to its friends, which looks like a human head and torso. It has highly-precise microphones in its anatomically accurate ears, which we use to listen to playback. HATS sends the data it collects to SoundCheck, an electroacoustics analysis program developed by our pals at Listen, Inc. This program analyzes the data, then churns out pretty graphs that we use in the reviews. If you'd like to know more about our laboratory or what happens inside it, read this article.
Frequency Response (5.14) 
How the test works:
What we're looking for here is how the headphones emphasize any given frequency. Ideally, the playback would sound identical to the recording, but some people enjoy a dynamic response, such as boosted bass. What we do to test this is play back a frequency sweep at a known decibel level. We can then map the added or subtracted emphasis at any given frequency.
What we found:
The Audio-Technica ATH-ANC7s' frequency response was good overall. It starts out with a slighty boost to the bass that will make lower frequencies sound strong, but not overly boomy. The graph then stays within the limits with two exceptions. The first is negligible, where the right channel peeks above the top limit. The second is slightly more severe, where the left channel dips below the lower limit. This still isn't that bad of an issue, however, since the amount of deemphasis is relatively minor.
The ATH-ANC7s have a fine response overall. It isn't perfect, but its imperfections aren't particularly noteworthy. They also have a dynamic lilt, meaning you should listen to them before you buy them, in order to discern whether or not you like their sound.
How the Audio-Technica ATH-ANC7 compares:
The average score for this section is exactly 4.00, so the Audio-Technica ATH-ANC7s are above average. They actually managed to score better than all of the comparison headphones below, which all went outside the scoring limits by significant amounts.
This was actually a surprising result on a set of active noise cancellers. As you can see by the comparison headphones below, active-cancellers aren't known for having the most even frequency responses.
Distortion (3.26)
How the test works:
Distortion refers to any changes between the original soundwave and what your headphones spew out. Distortion is bad in general, but the depth of this badness depends on what you listen to. If you're a punker or metalhead, congratulations: you probably won't notice most levels of distortion. If you listen to classical, you're far more likely to notice an instrument or freuqency range sounding distorted.
What we found:
The ATH-ANC7 did have some small issues with distortion, showing a bit around the 1kHz mark and a blip further down the line that was only present in the right channel. Generally active noise cancellation headphones have issues with distortion, because playing inverse soundwaves back along with your music can either add noise or cancel out some of your playback as a side-effect. The ATH-ANC7s follow in this tradition.
We were surprised, however, to see distortion levels were actually significantly smaller when the active cancellation feature was engaged. When the feature was turned off, the graph displayed about 4% distortion at the 100Hz level. After the distortion problems in the bass, however, the headphones displayed less distortion around the 1kHz mark. Regardless of whether noise cancellation was turned on or off, the right channel still showcased that tiny 1% blip towards the higher end.
How the Audio-Technica ATH-ANC7 compares:
The ATH-ANC7s actually scored the lowest out of all the comparison headphones. This is partially due to the distortion staying above 0.5% for the first half of the graph, rising at the 1kHz mark, then dropping back down closer to zero. It's also partially due to the spike in the right channel, but since that incident only affects a small area, it doesn't account for much.
Tracking (8.00)
How the test works:
Tracking refers to your headphones' balance of volume. If the right channel is louder than the left at any point, or vice versa, then your headphones don't have perfect tracking. Fortunately, HATS can very easily tell how bad tracking is, by listening to a tone being played through both channels at the same decibel level. If it senses any difference in volume levels, it'll show up on the graph below.
What we found:
The ATH-ANC7s actually did well on this tracking test, despite the rather rough-looking graph to the right. The main area of concern is that dip around 1kHz, where the right channel increases in volume. This swing, however, is less than 5dB, which isn't a particularly noticeable amount. Also, the transition isn't particularly steep. On the way up, the line is more steep, but again, since we're dealing with such small fluctuations – 2.5dB louder on the right to 2dB louder on the left – we doubt anyone will notice. After that initial dip, the graph gets slightly erratic, but again, the individual fluctuations won't be noticeable. There is a significant drop towards 10kHz, but all headphones have odd tracking towards the high end. This is partially due to HATs inability to provide 100% accurate results for the extreme low or high end. We thusly don't score on those area, but we leave them in the graph to show a general trend. For example, in the graph at right, you could expect the right channel to become louder than the left, then the left will gradually usurp the right.
How the Audio-Technica ATH-ANC7 compares:
The ATH-ANC7s did very well here, coming in second place to the Shure SE420s. If you look at all the graphs, the only comparison that might not be clear is between the ATH-ANC7s and the Sony MDR-NC500Ds. First of all, the dips and peaks on the NC500Ds are slightly larger. Second of all, the graphs we display here are normalized, to enhance their readability. One of the NC500Ds' peaks or valleys might be slightly more extreme than what's pictured here.
Maximum Usable Volume (8.57)
How the test works:
This test is actually a series of distortion tests held at varying levels. What we're looking for is the maximum volume output the headphones are capable of that stays within 3% distortion. As volume increases, so do distortion levels, and that 3% mark is more than enough to be noticeable.
What we found:
The ATH-ANC7s are capable of outputting 114.00 decibels, which is average. Most headphones can output 110-120dB, which is what we award maximum points for. Anything louder than that is damaging. Reaching 114dB without significant distortion levels isn't bad, and should appease most listeners. If you want your headphones to be louder, you could check out the Shure SE420s or the Bose QC3s.
One thing to keep in mind: the ATH-ANC7s are louder when their active cancellation is turned on. We're guessing they use some of the battery life to boost volume levels.
Isolation (5.51)
How the test works:
Isolation refers to how well the headphones can stop external noise from entering your ears. There are two types of isolation: active and passive. Passive cancellation is caused by physically obstructing sounds from entering your ears. Putting your fingers in your ears is a type of passive isolation. Active refers to fancy electronics that listen to surrounding noise, then play back sound of an inverse amplitude. As you'll remember from 6th grade science, a wave plus a wave of a perfectly inverse amplitude equals a flat line, which is inaudible. On our isolation test, we simply blast the headphones with pink noise (all octaves playing with equal power) and see what makes it through to HATS waiting microphone-ears.
What we found:
The active cancellation feature is a bit weak on the ATH-ANC7s. Typically active cancellers block out a lot of bass. While the ATH-ANC7s will block out more bass with active cancellation turned on as opposed to when it's off, the difference isn't as significant as we usually see.
Also, note how the active cancellation's graph dips below the passive cancellation's graph above 1kHz. This means the active cancellation feature is actually generating more noise than it's blocking out at this level. This is an unfortunately ubiquitous side-effect of current active cancellation technology.
How the Audio-Technica ATH-ANC7 compares:
As you can see below, the ATH-ANC7s aren't the best active-cancellation headphones. While they will help reduce a lot of bass noise, they simply don't block out as much as many of the competing models. Like most other active-cancellers, the feature does create a bit of noise above 1kHz. You would be better off with a pair of in-ears, if you don't mind the aural intrusion.
Leakage (3.11)
How the test works:
To test leakage, we put a microphone a set distance away from our headphone-outfitted HATS and then play pink noise through the headphones. The microphone then reports everything it hears back to SoundCheck.
What we found:
The ATH-ANC7s leak like crazy. This is really unfortunate on an active noise canceller. When you put on active-cancelling headphones, even ones with weak cancellation, they create a strong sensation that you're isolated from the outside world. This is rarely the case, however, because unlike passive cancellation, active cancellation only works one way: by dampening incoming sounds. Active cancellation (currently) does nothing to dampen outgoing sounds. Therefore, while you're listening to Barbie Girl by Aqua, thinking you're enjoying your 90s Mega-hits CD in total privacy, everyone around you will be able to hear every word. Leakage is exacerbated with the volume of your playback, but even at a moderate volume level the person next to you on a bus or anyone in a neighboring cube at your office will be able to hear your playback. These are not headphones to wear at your local public library.
|
