Speakerphone and Audio

The Nexus 4 has a small vertical notch cut out of the back glass for its speakerphone port. The unfortunate part is that when the Nexus 4 is laid display-up like I always place phones for testing under our digital sound level datalogger, it is quite muted since there is no gap in the cavity for sound to escape through.

Speakerphone Volume - 3 inches Away

With the phone raised, however, the Nexus 4 turns out to be decently loud, which matches my subjective impressions using the device for Google Navigation over the past few days.

Noise Suppression

The Nexus 4 has a pair of microphones for noise suppression both when on calls, and also for the increasingly important task of reducing noise on ASR (Automatic Speech Recognition) workloads like Google Now. I believe the Nexus 4 is using Qualcomm’s Fluence for this task, which is an adaptive beamformer system.

Google Nexus 4 - Noise Rejection by AnandTech

To test its efficacy, I turned to the industry standard babble track and ramped volume in front of a pair of speakers to 94 dBA (very loud) and then back down while recording the mobile-terminated end of the call on my PC. I should note that when I run these tests I always originate and terminate the call on the same mobile operator (in this case T-Mobile) if possible.

The Nexus 4 does a pretty decent job at canceling noise on my test call. The Galaxy Nexus noise rejection performance quite honestly never was that spectacular, and getting better noise filtering is going to be an increasingly important part of the speech recognition battle on these platforms.


Inside the Nexus 4 is a Qualcomm WCD9310 audio codec, which we’ve seen in other devices like the MSM8960-based Galaxy S 3s and a few other phones. Measuring sound quality is probably the number one requested addition to our reviews, and still is a rather nebulous thing to measure at times. For this I worked together with the ever-awesome François Simond (@supercurio) to measure sound quality on the Nexus 4 using RMAA on my desktop equipped with an ASUS Xonar Xense sound card.

Subjectively the Nexus 4 doesn't sound terrible to my ears on a pair of SE535s and listening to music at half volume or less. Objectively however the results are less than awesome thanks to a combination of things. First, audioflinger is set to 48 kHz which results in software resampling causing artifacts for 41.1 kHz source material. Second, there appears to be different modes that the Nexus 4 switches into depending on your volume level, and the frequency response plots show these different plots at the number of different volume levels we tested. We're going to update with some thoughts from Francois about the Nexus 4 soon, for now I think the Nexus 4 sounds ok at least when it comes to the most glaring of things — I couldn't detect any background hiss or whine as the SoC changes states, which is a huge percentage of what I normally wind up hearing on smartphones. 

Cellular, Wi-Fi, GNSS Conclusions and Final Thoughts


View All Comments

  • Impulses - Tuesday, November 13, 2012 - link

    There's an app a ton of people are using with the N7 sans root that allows them to import or even stream video from USB devices using OTG, it's a pretty solid workaround for those that would rather avoid rooting. Reply
  • thesavvymage - Wednesday, November 14, 2012 - link

    know what this app is called by any chance? I havent heard of any way for them to read off a usb without rooting Reply
  • Freedomuser - Wednesday, November 14, 2012 - link

    The none-root app called Nexus Media Importer. There is a thread in accessories in xda for DIY USB OTG to microSD is great. Check it out. Reply
  • andybryant - Wednesday, November 14, 2012 - link

    I guess this is the thread

    Sounds like an opportunity for a kickstarter.

  • twtech - Tuesday, November 13, 2012 - link

    I would be tempted to try this phone, except for the battery life. That could probably be mitigated somewhat by buying a few charging mats, but still I don't think I could ever go back from having all-day no hassle battery life to having to watch the battery meter again to make sure that my phone isn't going to turn off.

    Also, the glass back sounds a bit dangerous, but it's a relief to hear you dropped it a few times with no ill-effects.
  • Rits - Tuesday, November 13, 2012 - link

    Brian, let me thank you for this fantastic review. Its probably going to be the definitive review of the Nexus 4. The level of detail just made me smile! And thanks for the audio fidelity part (graph missing?) and teaming up with François was just what I needed. I'll await his (or your) detailed analysis of that part.

    Keep up the great work. :)
  • wffurr - Tuesday, November 13, 2012 - link

    What an incredibly thorough review. This is the first Anandtech smartphone review I have read, and I am seriously impressed. Thank you for all your hard work.

    One thing that I would like to see included is the brightness, black level, and contrast measurements for the Galaxy Nexus. Are they not included because it's an AMOLED display?

    That's my current phone, and I also think it's instructive to see the improvement in the Nexus line against its direct predecessor.
  • MadMan007 - Tuesday, November 13, 2012 - link

    Out of those, brightness is the only thing you can meaningfully measure for AMOLED. Black is 0 and contrast is therefore 'infinite.' Note that the Galaxy Nexus is listed on the brightness chart. Reply
  • Guspaz - Tuesday, November 13, 2012 - link

    I'm confused. The phone seems to have horrible performance, making it one of the slowest Android phones in the benchmarks (doesn't matter to users why the browser benchmarks are so bad, only that they are) and terrible overheating problem, but it's "the phone to get?"

    It sounds more like a critically flawed product that should be avoided at all costs. There are plenty of other Android phones that don't have performance or overheating problems.
  • uhuznaa - Tuesday, November 13, 2012 - link

    It's really cheap, though. Don't underestimate the draw of being able to afford it without much thinking. Worked great with the Nexus 7 too.

    Personally I'm really pissed off by the battery life despite a huge battery, this thing is quite a brick.

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