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.

Audio

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
POST A COMMENT

188 Comments

View All Comments

  • dishayu - Wednesday, November 14, 2012 - link

    Meh, that is how they statistically show you that thermal throttling is affecting the performance. Your accusation would have help good if they had only published the freezer benchmarks. But they published both because they wanted to showcase that the phone thermally throttles itself (i.e. a negative point about the phone)... How exactly is that partial? Reply
  • kgh00007 - Monday, November 19, 2012 - link

    I think it is particularly significant that this phone was selected to be the first phone that was actually put in a freezer and the results published, why not the iPhone or some other phone that was known to be trottling?
    Seriously, think about it.
    There is a big difference between stating that a phone throttles and the theoretical performance is X and actually putting a phone in the freezer and publishing the resulting benchmarks.
    I am entitled to my opinion, and my opinion here is that somebody is working for the man, the wrong man.
    Reply
  • kgh00007 - Monday, November 19, 2012 - link

    There is quite a big difference between stating that a phone is throttling and the theoretical performance should be X, and putting a phone in the freezer and publishing the resulting benchmarks.
    The choice of phone to be the first to recieve this treatment is suspicious to me.
    My opinion, which I am entitled to, is that somebody is working for the man, the wrong man.
    This is evident to me, think about it yourself.
    Reply
  • thesavvymage - Wednesday, November 14, 2012 - link

    they basically said "the phone IS being thermally throttled. here's what would happen if it wasnt..."

    nowhere does it ever say that the freezer tests would ever be indicative of a real world test. they are just showing for information
    Reply
  • kgh00007 - Monday, November 19, 2012 - link

    People are aready taklking in the comments about how this phone has to be put in the freezer in order to gain maximum performance from it.
    People are not saying the same about the iPhone, that is the significance.
    As I said something fishy going on here and I don't like it.
    In fact this is the first time Anandtech has dissapointed me with a review, but it is a rather large dissapointment.
    Reply
  • galtma - Wednesday, November 14, 2012 - link

    Is it feasible to replace the RAM in the N4 to upgrade it to 32gb? Where in the internals would you dig? Reply
  • noblemo - Wednesday, November 14, 2012 - link

    I think you are referring to the NAND Flash, but in either case the NAND and RAM are soldered to the mainboard. Brian made the following comment in the section, "Inside the Nexus 4" (page 7 of the review) regarding the NAND:

    "I couldn’t get the can off of what appears to be the eMMC (the only remaining large package), we’ll have to see if anyone else wants to do some destructive digging to get that one."

    He is referring to the device under the EMI shield (with a QR code label) in the lower left corner of this image:

    http://images.anandtech.com/galleries/2435/Nexus-4...
    Reply
  • praveen44 - Wednesday, November 14, 2012 - link

    Excellent review. Reply
  • spiritrajat - Wednesday, November 14, 2012 - link

    most exhaustive review..being an electronics engg myself i realy enjoyed going through the reveiw...job very well done Reply
  • noblemo - Wednesday, November 14, 2012 - link

    Q: Hey, Nexus 4, why so blue?
    A: Because no one at Google is responsible for display calibration.

    It's unfortunate that color accuracy does not get more attention from manufacturers.

    Was throttling observed and was there a noticeable impact during daily usage? Any thoughts on whether it would be an issue in climates with ambient temperatures greater than 30C?
    Reply

Log in

Don't have an account? Sign up now