Speakerphone Volume

In my N900/Motorola Droid piece, I alluded to an interesting note I made about the iPhone 3GS's speaker volume. For a long while, people have complained that the iPhone's speakerphone volume was too quiet, complaining that even at the maximum volume it was nowhere near loud enough. The same applied to noise level over the handset through the earphone speaker.

I've noticed a similar issue, but picked out another detail while testing the AT&T MicroCell - calls on 2G are louder than calls on 3G. After I got my soundmeter, I set out about measuring, and found that my suspicions were confirmed. Calls on 2G GSM are indeed significantly louder than calls on 3G UMTS on the iPhone, and curiously not so on the Nexus One. The reason? Dynamic range compression.

If you're familiar with the FM loudness war, than you'll instantly understand what's at play with 2G versus 3G call loudness. Calls placed over GSM have a smaller dynamic range, while 3G calls over UMTS have greater dynamic range (and fidelity). The dynamic range of GSM is roughly equivalent to CDMA 1xRTT (which is what all calls on Sprint and Verizon are placed over - not over 3G Ev-Do), though that's a whole other can of worms to discuss. Regardless, when users unfamiliar with the inherent difference in fidelity hear a 3G call after getting accustomed to 2G loudness from 1xRTT or GSM, it sounds notably quiet on the iPhone.

This is a problem that's existed since the iPhone 3G, and has gone unchecked in the 3GS, and 4. For whatever reason, Apple isn't increasing the gain on 3G to match the same loudness, possibly to preserve fidelity, and the result is that the speakerphone and earpiece are never as loud as they really could be compared to a 2G call. As I mentioned before, Android on the Nexus One appears to use an automatic gain algorithm to normalize loudness. If you place a 3G call and listen carefully, you can actually hear the gain ramp up to meet the same loudness as the 2G GSM call.

The difference between these phones might not look like much, but keep in mind the logarithmic nature of dB: -3 dB is half the loudness. 

On the iPhone 3GS, the difference is 7.36 dBA, while the iPhone 4 somewhat lowers it down to a still-audibly-different 3.31 dBA. The Nexus One shows no difference in loudness between 2G and 3G, correcting both to a (likely purposefully exact) 80 dBA. The iPhone 4 is indeed louder than the 3GS, by 4 dBA. It's a difference, but not an overwhelming one. I'd say the iPhone 4's speakerphone is still loud enough, though calls over 3G are still a bit too quiet. Until Apple increases the gain on 3G calls, iPhone 4 customers who are hard of hearing should invest in a bluetooth headset.

Sidebar: Luxa2 H1-Touch, a Great FaceTime Stand Performance
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  • strikeback03 - Tuesday, July 6, 2010 - link

    I would assume they were referring to the launch of Windows Phone 7, which may prove to be a viable smartphone competitor. But being still months away that is a long time for competitors to move ahead.

    Also, as far as hardware goes, there are phones built with modern hardware, such as the HTC HD2. The software is the real problem.
  • softdrinkviking - Sunday, July 4, 2010 - link

    the biggest turn off for me is still the lack of micro SD support.

    i use my phone as my primary mp3 player, and i end up filling up 16GB really quickly.
    with SD cards, you can swap out your storage on the go, rather than having to return home and do a sync in itunes.

    also, itunes is awful. it's such a pain in the ass to use, and i can think of no good reason that we can't drag and drop mp3 files onto our phones, or better yet, onto SD cards. (other than the fact that apple wants to force you to go through their online marketplace on a regular basis)
  • D3lta - Sunday, July 4, 2010 - link

    By far the best review I've ever read. Thanks and keep up the good work.
  • avoidz - Sunday, July 4, 2010 - link

    Cynical maybe, but I'm sure this was all part of the plan, knowing that users would require the $30 bumper case.
  • Consolidated - Sunday, July 4, 2010 - link

    A rough (eyeball) estimate of your diagram finds the umts antenna to be about twice as long as the WiFi antenna. Connecting the two would increase the length of the umts antenna about 50%, midway between the base length and the first harmonic length. Nasty VSWR there.
    The same calculus INCREASES the wifi antenna length by a factor of three, just about the second harmonic (an odd harmonic, yes but way better than midway between, no?).
  • zero01 - Sunday, July 4, 2010 - link

    This is a must have, I hear it fixes everything

    Very funny although I cant see them selling many.
  • docflash - Sunday, July 4, 2010 - link

    as a physician, i've had lots of patients who've had allergies to metal - nickel in particular. an effective fix is coating the metal, often in a ring or other piece of jewelry, with a couple of layers of clear nail polish. this doesn't allow their skin to touch the metal, and stops the allergy.

    it's *possible* that some clear nail polish would have the same effect on the metal of the iP4's antenna. now, i am not an engineer (nor do i play one on TV) but i see no reason this won't work. and if it does: well, i'm in the market for a new phone, and the iP4 could be it.

    if it *does* work for you, great! but share the news - i'd like to try it myself (and so might other folks).
  • scubasteve03 - Monday, July 5, 2010 - link

    I have searched everywhere! Where can I find that the background on the home screen in the " The Real Story on iPhone 4's Antenna" section? It has the vertical stripes that is yellow and black. If anyone could please help me figure out where to get send me an email. First person to find it for me gets 10 internet points! selphs03@gmail Thanks everyone!
  • Romion - Monday, July 5, 2010 - link

    First of all, regarding battery life I dont think that the real talk time is bigger than what Apple announced (about 7h). I know from experience that all my phones till now had talk times around 1/2 up to 2/3 of what manufacturer announced (the talk time announced is IDEAL, most probably non existent in real life.) Just curios, how did u check the talk time?

    BUT, MAYBE THIS IS A MAGICAL DEVICE AND I AM ALL WRONG.

    Anand, if u use some technical data this doesnt mean that they are correct/ true and we can rely on this review.
    U said that u were in line at mall for every Iphone model till now, well, that tell us/me everything.
    Sorry if my english is not perfect, im not a native english speaker, but a smart enough guy to see things how they are in reality and not listen to others in their bias reviews.
    gl
  • Stoli89 - Monday, July 5, 2010 - link

    It would be interesting to understand if changes to the WiFi/Bluetooth/GPS portion of the antenna system has an impact on the 2G/3G portion. If energy from wifi and/or bluetooth and/or GPS is causing interference with the 2G/3G signal processing when the so-called "gap" is conductively bridged. Current test seem to focus on the 2G/3G antenna being de-tuned when the external antenna gap is bridged, without considering if energy is also leaking through and corrupting the 2G or 3G signal(s). Just curious if this is just one more parameter which has confused the outcomes for different customers.

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