The iPhone 6 Review
by Joshua Ho, Brandon Chester, Chris Heinonen & Ryan Smith on September 30, 2014 8:01 AM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone 6
Audio Quality
The iPhone 6 is the first non-Android phone to be put onto the Audio Precision APx582 for audio testing. The exact same test tones are used as with Android devices, but they are played back through iTunes at maximum volume. We use the same four static loads as we did with the HTC M8 and Samsung Galaxy S5 for the results you see in the table below.
| 15 Ohm | 33 Ohm | 150 Ohm | 330 Ohm | |
| Dynamic Range | 84.155 dB | 92.281 dB | 92.223 dB | 92.160 dB |
| THD+N | 5.873% | 0.0054% | 0.0032% | 0.0032% |
| Crosstalk (L) | -49.608 dB | -56.239 dB | -71.721 dB | -77.966 dB |
| Crosstalk (R) | -49.831 dB | -56.459 dB | -72.191 dB | -77.983 dB |
| Output Power | 44.04 mW | 26.39 mW | 6.614 mW | 3.072 mW |
| Output Voltage | 812.7 mVrms | 933 mVrms | 997 mVrms | 1,007 mVrms |
| Relative Level (20Hz - 20kHz) | ±0.088 dB | ±0.088 dB | ±0.089 dB | ±0.088 dB |
The first thing to notice is the 15 Ohm load test. At maximum volume, with a -0dBFS signal the amplifier section in the iPhone 6 enters clipping. You can reduce the volume to avoid this, but it does not do as well with really hard loads as the M8 does. You can see the 1kHz sine wave for that below, with the amp clearly clipping at the bottom.
iPhone 6 997 Hz Sine Wave 0dBFS, 15 Ohm Load
For most testing I focus on the 33 Ohm load, as most in-ear headphones have a rated impedance around 32 Ohms. A data comparison to the HTC M8 and the Galaxy S5 is in the chart with the S5 as the clear loser.
| HTC M8 | iPhone 6 | Galaxy S5 | |
| Dynamic Range | 92.074 dB | 92.281 dB | 91.921 dB |
| THD+N | 0.0152% | 0.0054% | 0.0505% |
| Crosstalk (L) | -64.780 dB | -56.239 dB | -44.767 dB |
| Crosstalk (R) | -64.329 dB | -56.459 dB | -44.804 dB |
| Output Power | 47.63 mW | 26.39 mW | 10.63 mW |
| Output Voltage | 1.254 Vrms | 933 mVrms | 592.4 mVrms |
| Relative Level (20Hz - 20kHz) | ±0.664 dB | ±0.088 dB | ±0.081 dB |
Compared to the M8 the iPhone 6 isn’t quite as powerful, but it has lower THD+N and a much better relative level. The relative level isn’t a big deal, as a variation of 0.5dB is unlikely to be heard by most. That the THD+N is 1/3rd the value of that on the HTC M8 is more important, as the FFT below shows a very low noise floor on the iPhone 6 when compared to the one in for the M8.
iPhone 6 997Hz 0dBFS Sine Wave FFT
HTC M8 997Hz 0dBFS Sine Wave FFT
The crosstalk is also lower on the HTC, which is an area the iPhone 6 could certainly improve in. Digging into more depth on the THD+N results provides a bit more context. The HTC M8 has THD+N levels that start at 0.03% but after 2kHz it begins a steady rise up to 0.1% at 10kHz and past 0.2% at 20kHz. In contrast, the iPhone 6 THD+N is 0.03% until 500Hz, rises up to 0.06% at 5kHz, then back down to 0.03% at 9kHz, and peaks at 0.1% by 20kHz. The iPhone 6 will have slightly more midrange distortion but less treble distortion.
iPhone 6 THD+N Ratio Frequency Sweep
HTC M8 THD+N Ratio Frequency Sweep
If we leave noise out of it and look only at distortion then the iPhone 6 does even better. It has a distortion level of -95dB out to 10kHz and then it rises up to -82dB at 20kHz. The HTC M8 begins at -77dB for 20Hz, falls to -95dB until 2kHz, and then rises up to -56dB by 20kHz. The bass and midrange distortion is about equal, but the HTC M8 has far more distortion in the treble.
iPhone 6 Distortion (Noise) Frequency Sweep
HTC M8 Distortion (Noise) Frequency Sweep
Is one phone superior to the other? With the iPhone 6 and M8, I don’t believe so. The M8 is more powerful with lower crosstalk while the iPhone 6 has less distortion and better frequency response. Most notably the iPhone 6 has no results that indicate odd behavior, which we have seen with the Galaxy S5 and other phones. It is a well engineered headphone amplifier provided you do not need to listen to something at maximum volume with a 15 Ohm load.
Can Apple improve this? They could improve crosstalk, though some headphone companies like more crosstalk to help create an image more like a pair of stereo speakers than headphones. They could also support 24-bit audio which can improve on the SNR values here. The test tones are only 16-bit in nature, so the SNR maximum value is around -98dB. The HTC M8 may perform better given 24-bit test tones but would need a retest to verify this. Apple seems to have decided on using Lightning with an external DAC to push beyond 16-bit audio so we will have to wait for devices using that to see.
Audio hardware on phones can still improve a lot to get closer to where the best stand-alone products are. Those are capable of Signal-to-Noise ratios of -120dB or greater, and crosstalk of -110dB or more. How much those would be audible with headphones is uncertain, but when used as a source device with a stereo it may be audible. However, unless high-resolution audio downloads, like Pono or HD Tracks, really start to catch on I don’t see this being a main focus for most of the companies out there. The iPhone 6 is more likely what we will see going forward: good audio quality, but most importantly free of any major issues.
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Oxford Guy - Saturday, October 4, 2014 - link
"With Cyclone Apple hit on a very solid design: use a wide, high-IPC design with great latency in order to reach high performance levels at low clock speeds. By keeping the CPU wide and the clock speed low, Apple was able to hit their performance goals without having to push the envelope on power consumption, as lower clock speeds help keep CPU power use in check. It’s all very Intel Core-like, all things considered."The G4 and G5 processors were wide when Intel was doing its lame NetBurst thing. The "wide and shallow" G4 in particular had low clock speeds. The "wide and deep" G5 bumped them up a bit. The "narrow and deep" NetBurst was the high clock speed awful performance per watt Intel brainchild.
Coup27 - Saturday, October 4, 2014 - link
"Fortunately, based on the USB device information for the phones, both the iPhone 6 and 6 Plus support charging with power adapters like the iPad charging block that can provide up to 2.1 amps at five volts. Using one of these chargers will dramatically reduce charge time on the new iPhones, and it's a very worthwhile investment (assuming you don't already have an iPad) for the iPhone 6 Plus in particular."If this was any other phone manufacturer they would have been lambasted for taking the cheaper route and not providing a charger which charges the battery in the most optimal time. However, with this being Apple and all, it's perfectly acceptable to ship a 1A charger and it's a "worthwhile investment" for the user to buy another charger (if they don't already have one) with a higher current to charge their phone faster.
Simply not acceptable. As much as I love this site, this review is no more than the typical Apple fodder which is trotted out all over the web. The fact that one German publication was recently struck off the media list by Apple for posting a bending video of the 6 Plus vs Note 3 shows what happens when the media dare say something negative and it's quite clear they would rather stay on Apple's good side than be truly honest in their reviews.
There was no mention in this review about half the hardware choices made here. The screen ppi was very lightly glossed over. No mention of the lack of stereo speakers or waterproofing to name but a few. Someone suggested that waterproofing adds a lot of bulk to the phone. On the S5 I would agree, however the Xperia Z3 is only 0.4mm thicker than the iPhone 6 so it can be done whilst still looking stylish.
Apple produced marketing photos where they photo shopped out the camera bump. Yet here it is described as an "interesting design choice". No mention of it wobbling all over the place when placed on a flat surface. Let's look at PDAF. Given virtually no time on the S5 review but a full explanation given here. The S5 review was also 10 pages long written by 2 people, this is 14 pages written by 4 people.
Sometimes you can't move on the home page on this site for articles about Apple, yet there has been nothing so far, not even a pipeline story about the disastrous bugs coming out of iOS 8.
Add to this the badly managed silent departures of Anand and Brian to Apple, I don't think there's much point reading Apple reviews any more.
tralalalalalala40 - Sunday, October 5, 2014 - link
1) Everyone charges overnight, no difference to user experience.2) No proof that german media site was struck off some magical list.
3) ppi does not equal quality. (Unless you believe more MP is better, then please just go buy a lumia)
4) no phone is water proof, it's a range of water resistance.
5) no proof that apple photoshopped their own marketing material to change the camera design
6) no one uses their phone with the back flat on the table
7) every OS has bugs, the issue is that apple actually gives out upgrades (que the majority of android users still stuck with a massively susceptible default browser). You won't hear about android L issues because it will take 2+ years to be on 20% of android phones.
8) employees change jobs. everyone knows about it, do you want a NYTs editorial about it?
9) if you want non-scientific reviews go to cnet.
Coup27 - Sunday, October 5, 2014 - link
I can't decide which is worse. The answers in post, or the arrogance.1. Not true. People's lives are all different. To suggest everyone's phone can last until they go to bed is a massive generalisation. The supplied charger should charge the phone in the most optimal time, regardless when the phone is charged.
2. http://blog.gsmarena.com/apple-completely-loses-pl...
3. Why are you talking about two different things? ppi is clearly directly related to quality. You could have the best panel money could buy but if the ppi was 96 on a 5" screen it would look terrible. It is now widely accepted, and even mentioned in this review that ~450 ppi is a perfect balance between resolution and battery life. MP has no relevance in this discussion.
4. There are many IP67 phones which are immersion proof up to 1M for 30 minutes. There are now IP68 phones which are immersion proof beyond 1M for 30 minutes. If they phone can be dunked under water, that's water proof.
5. http://blog.gsmarena.com/apple-iphone-6-features-c...
6. Do you speak for everybody in the world?
7. KitKat and Jelly Bean account for over 75% of Android devices. (Google it if you want the source). Yes, budget phones are often left behind in software, but that's because they are budget phones. People sign up for that experience when they pay a fraction of the cost of an iPhone or Android flagship.
8. Anand moving to Apple should have broke on this site, not every other tech site. Anand has gone on for years about openness and honesty. Where was it then? Brian disappeared completely and despite multiple requests, nobody would say where he had gone. That news was also broken by other tech sites. It was like AT had something to hide. Nobody would have really cared if they had gone to Apple, so why do it in the shadows.
tralalalalalala40 - Wednesday, October 8, 2014 - link
1) If you need a phone to last an inordinate amount of time get the charging cases.2) Hoax, they are invited to the ipad air 2 event: https://twitter.com/CB_Telzerow
3) false, if samsung released a 5000 ppi phone that was slow as hell (like the note 4 is http://appleinsider.com/articles/14/10/04/samsung-... ) how is that high quality? iPhone 6 was proven to have the best color which is more important than pixels you can't see.
4) yep, you can get a case for this if this is your thing. there is more choice with apple here since there are 1000x as many cases to suit your need. (with android you are locked in to what the device maker makes since there aren't that many niche cases)
5) thanks for the proof. no photoshop just choice of angles. go look at the apple website for many angles of the bulge if that is your thing.
6) in this case yes, it's not ergonomic to use the phone that way. it's why droid makers gave up on the kickstand
7) that number is for those that use google play (which accounts for <8% of all android phones, lol)
8) name another news site that had a going away article by one of the employees. especially one going to work for a company that requires employees to not bring attention to themselves (think non-compete)
thanks
gonsolo - Monday, October 6, 2014 - link
I'd like to see a benchmark of app startup times since this is where I have to wait most of the time nowadays.tralalalalalala40 - Wednesday, October 8, 2014 - link
http://www.cultofandroid.com/69538/iphone-6-multit...iphone 6 is blazing fast. note 4 needs 32 cores to compete.
falc0ne - Tuesday, October 7, 2014 - link
"In battery life, once again Apple has managed to successfully maintain good battery life despite a relatively small battery capacity". Seriously? Since when iPhone has a good battery life. You can never go through the day with one. Everyone knows that. Sorry guys but ain't buying that. If this is good, then what does that make Xperia Z3? Good of Thunder in battery? :)falc0ne - Tuesday, October 7, 2014 - link
**God of thunder:) autocorrect dictionary typo . anyway...you get my pointHook Em14 - Tuesday, October 7, 2014 - link
Wow...hardcore Android fanboys have to be some of the most ignorant, illogical, and pathetic people around.