The iPhone 5 Review
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on October 16, 2012 11:33 AM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone 5
Speakerphone and Noise Suppression
Section by Brian Klug
When Apple changed up the dock connector with the smaller Lightning port, it afforded a chance to also redesign the speakerphone at the bottom of the iPhone 5. Between the iPhone 4 and 4S we saw minimal changes, and performance was acceptable if a bit on the quiet side. With the iPhone 5 Apple advertised a big gain in audio quality with both changes to the speaker and a 5 magnet transducer design.
We normally test speakerphones by calling the local ASOS test number at max volume in front of an Extech sound data logger sampling continually and then averaging over one readout of the weather report. This gives a good feel for the overall loudness of the speakerphone on a call, but doesn’t tell us anything about quality unless you’re standing in front of it. In this case, the iPhone 5 is quite loud and comes in near the top of our scale at 81.8 dBA. It isn’t chart topping but a definite improvement over the relatively quiet 4/4S speakerphone design.
I decided to do something different though after getting a lot of questions and emails asking for a better quality comparison between the iPhone 5 speaker and its predecessor. People are interested in using their smartphones to listen to music when speakers or a dock aren’t available, and I thought this worth investigating. To get to the bottom of this I used my Blue Yeti USB microphone and arm which I use for podcasting to record the speakerphone output at 90 percent volume on the iPhone 4S and iPhone 5.
I started with the test call, which sounds surprisingly different between the iPhone 4S and iPhone 5. The 4S saturates and has obvious distortion even at 90 percent volume. This is quite noticeable in the recording. It then occurred to me that because I’m calling over AT&T (narrowband AMR) and to a PSTN (public switched telephone network) that the call would be limited to 4 kHz thanks to filters along the route, therefore anything above 4 kHz is undesirable. I took a spectral analysis (which shows power spectral density), and instantly it became obvious just how much energy there is on the 4S above the 4kHz limit from overmodulation or saturation/clipping on that speakerphone design. Meanwhile the iPhone 5 has much less energy over that 4 kHz maximum for a PSTN call.
I did the same for two songs recorded start to finish, and the differences are quite noticeable even in my rather quick and dirty recording plus spectogram comparison. I cropped the two recordings of the songs quite a bit and stuck them on soundcloud.
My overall impressions with the iPhone 5 speakerphone is that it has much less of a tendency to clip and saturate than the 4S, all while being noticeably louder. It’s still a smartphone speakerphone but to my ears the difference is pretty dramatic.
Noise Suppression
We’ve known for a while now that Apple changed up the slot for noise cancellation in the iPhone 5. The story goes something like this — Audience was a discrete chip on the iPhone 4, an IP block on the A5 SoC for iPhone 4S, and also an IP block onboard the A6 SoC for iPhone 5. The difference is that with iPhone 5 Audience isn’t enabled, and the company knows this because final characterization with both the final industrial design, microphones, and performance was never performed. Audience claims it met all of its deliverables and targets with the new IP block it built and gave Apple for inclusion on the A6. There’s obviously a lot of speculation about exactly why Apple chose to go with its own soultion versus Audience.
We’ve seen Audience earSmart noise suppression processors in a number of smartphones to date, and carriers often have their own specification for noise suppression to get certified. In addition, with wideband voice (AMR-WB in the case of the iPhone 5) noise suppression is even more important, to say nothing of how big of a topic this is with voice recognition based features like Siri. While we’re on the subject of AMR-WB, this feature is enabled on the iPhone 5 but I’m unable to test it on any of the carriers in the USA at the moment.
Anyhow, the iPhone 5 uses an Apple-specific solution with three total microphones all around the device. One primary microphone at the bottom of the device where you’d expect the primary microphone to reside, a secondary microphone between the LED flash and camera module, and a third right next to the earpiece for use with earpiece active noise cancelation. Apple’s solution is a beamformer (Apple said so in the keynote) and from what I can tell thus works entirely in the time domain. I’ve spent a lot of time playing around with the iPhone 5 trying to characterize its noise rejection, and the system appears to have a number of modes it will kick into after a 5–10 second adaptation time.
Earpiece noise rejection is something I talked about on the podcast right after the iPhone 5 hands on, and is one of those modes that the iPhone 5 will kick into if you’re in a loud environment. It isn’t active all the time, but when it does transition into working it provides a noticeable suppression of ambient noise and the same kind of pressure I’ve felt with other active noise canceling closed ear headphones. The improvement isn’t overwhelming, but it’s a sensation and feature I haven’t experienced on any other smartphones to date.
The rest of the noise suppression story is really one of testing. To test, I ran our normal test suite which consists of me ramping ambient music to 94 dBA while speaking into the device under test and recording the other side of the call. I’ve gotten ahold of the industry standard babble and distractor tracks used by carriers for testing noise suppression and will move to those in the future, for now though the test track I currently play is something I understand pretty well.
The comparison here is between the iPhone 4S and iPhone 5 to see just how ambient noise suppression has changed with this change in solution. The difference in technique is pretty apparent, and again indicates to me that the iPhone 5 is working in the time domain. You can see visible cut in and cut out on the waveform. The Audience solution has some hiss that develops at the absolute highest background noise volume on the 4S, but it also does an excellent job suppressing noise. The Apple solution doesn’t have this hiss, but passes both background noise and vocals from the music passed through the call at maximum volume. I hate to call this a regression, but the difference in technique means that there’s audible background noise that gets passed on while I’m talking on the iPhone 5. I think for normal callers the difference won’t be readily apparent, but with close inspection it is dramatic.
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Calista - Sunday, October 21, 2012 - link
English is not my native language (as I'm sure you have noticed) and so the flow in the language is far from flawless. But I still believe my opinions are valid and that the review was too long-winded.Teknobug - Wednesday, October 17, 2012 - link
I live in a big city and I don't know a single person that went and got the iPhone 5, most are happy with the iPhone 4 or whatever phone they're using, I don't see what's so great about the iPhone 5 other than it being built better than the iPhone 4's double sided glass structure (I've seen people drop their's on the train or sidewalk and it shattering on both sides!).And what now? iPad mini? I thought Apple wasn't interested in the 6-7" tablet market, Steve Jobs said 9" is small enough. I know Apple tried a 6" tablet a decade ago but the market wasn't read for it back then.
name99 - Wednesday, October 17, 2012 - link
You know what AnandTech REALLY needs now?A comment moderation system like Ars Technica, so that low-content comments and commenters (like the above) can be suppressed.
Teknobug is a PERFECT example of Ars' Troll Type #1: "Son of the "I don't even own a TV" guy: "
This is the poster who thinks other people will find it interesting that he cares nothing about their discussion or their interests, and in fact judges himself as somehow morally superior as a result. The morphology of this on Ars Technica includes people popping into threads about Windows 8 to proclaim how they will never use Windows, people popping into threads about iOS 6 to proclaim that they never have and never will buy an Apple product, and people popping into Android related threads and claiming that they will never purchase "crappy plastic phones." In these cases, the posters have failed to understand that no one really cares what their personal disposition is on something, if they have nothing to add to the discussion.
ratte - Wednesday, October 17, 2012 - link
yeah, my thoughts exactly.worldbfree4me - Wednesday, October 17, 2012 - link
I finished reading the review a few moments ago. Kudos again for a very thorough review, however I do a have a few questions and points that I would like to ask and make.Am I wrong to say, Great Job on Apple finally catching up to the Android Pack in terms of overall performance? The GS3, HTC X debuted about 6 months ago yes?
Have these benchmark scores from the competing phones been updated to reflect the latest OS updates from GOOG such as OS 4.1.X aka Jelly Bean?
Clearly the LG Optimus G is a preview of the Nexus 4,complete with a modern GPU In Adreno 320 and 2GB ram. I think based on history, the Nexus 4 will again serve as a foundation for all future Androids to follow. But again, good Job on Apple finally catching up to Android with the caveat being, iOS only has to push its performance to a 4inch screen akin to a 1080p LCD monitor verses a true gamers 1440p LCD Home PC setup. Ciao
Zinthar - Thursday, October 18, 2012 - link
Caught up and passed, actually (if you were actually reading the review). As far as graphics are concerned, no smartphone has yet to eclipse the 4S's 543MP2 other than, of course, the iPhone 5.I have no idea what you're going on about with the Adreno 320, because that only gets graphics performance up to about the level of the PowerVR SGX 543MP2. Please see Anand's preview: http://www.anandtech.com/show/6112/qualcomms-quadc...
yottabit - Wednesday, October 17, 2012 - link
Anand, as a Mech-E, I think somewhere the anodization facts in this article got very wonkyI didn't have time to read thoroughly but I saw something about the anodized layer equaling half the material thickness? The idea of having half a millimeter anodized is way off the mark
Typically there are two types of anodizing I use: regular, and "hard coat anodize" which is much more expensive
If the iPhone is scuffing then it's definitely using regular anodizing, and the thickness of that layer is likely much less than .001" or one thousandth of an inch. More on the order of a ten-thousandth of an inch, actually. The thickness of traditional anodizing is so negligible that in fact most engineers don't even need to compensate for it when designing parts.
Hard-coat anodize is a much more expensive process and can only result in a few darker colors, whereas normal anodizing has a pretty wide spectrum. Hard-coat thicknesses can be substantial, in the range of .001" to .003". This usually must be compensated for in the design process. Hard coat anodize results in a much flatter looking finish than typical anodize, and is also pretty much immune to scratches of any sort.
Aluminum oxide is actually a ceramic which is harder than steel. So having a sufficient thickness of anodize can pretty much guarantee it won't be scratched under normal operating conditions. However it's much cheaper and allows more colors to do a "regular" anodize
When I heard about scuffgate I immediately thought one solution would be to have a hardcoat anodize, but it would probably be cost prohibitive, and would alter the appearance significantly
guy007 - Wednesday, October 17, 2012 - link
A little late to the party with the review, the iPhone 6 is almost out now...jameskatt - Wednesday, October 17, 2012 - link
Anand is pessimistic about Apple's ability to keep creating its own CPUs every year. But realize that the top two smartphone manufacturers (Apple and Samsung) are CRUSHING the competition. And BOTH create their own CPUs.Apple has ALWAYS created custom chips for its computers - except for a few years when Steve Jobs accidentally let their chip engineers go when they switched to Intel and Intel's motherboard designs.
Apple SAVES a lot of money by designing its own chips because it doesn't have to pay the 3rd party profit on each chip.
Apple PREVENTS Samsung from spying on its chip designs and giving the data to its own chip division to add to its own designs. This is a HUGE win given Samsung's copycat mentality.
Apple can now always be a step ahead of the competition by designing its own chips. Realize that others will create copies of the ARM A15. But only Apple can greatly improve on the design. Apple, for example, greatly improved the memory subsystem on its own ARM chips. This is a huge weakness on otherARM chips. Apple can now custom design the power control as well - prolonging battery life even more. Etc. etc.
phillyry - Sunday, October 21, 2012 - link
Good points re: copycat and profit margin savings.I've always been baffled by the fact that Apple outsources their part manufacturing to the competition. I know that Samsung is a huge OEM player but they are stealing Apple's ideas. They are doing a very good job of it and now improving on those ideas and techs, which is good for the consumer but still seems completely illogical to me from Apple's perspective. Must be the 20/20 hindsight kicking in again.