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.

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  • strikeback03 - Tuesday, July 6, 2010 - link

    How does international work? Are other parts of Europe covered by that as well or are they all additional?
  • B3an - Thursday, July 1, 2010 - link

    Theres way WAY less options for network and internet providers in the U.S, especially compared to here in the U.K..
    So less competition means higher prices. And of course the size of the U.S/Canada is a problem.
  • strikeback03 - Thursday, July 1, 2010 - link

    Some friends who have been living in England say that cell usage over there is way more expensive. They claim the only affordable way to do it is with pay as you go SIMs and just not use them much.

    But yes more competition would be nice. For me Verizon is the only carrier that offers the kind of coverage I need. So between the fact that I can't go anywhere and that they don't offer an off-contract rate I have no reason not to take the subsidized phones and contract extensions.
  • Chissel - Sunday, July 4, 2010 - link

    I'm an American living in the UK. iPhone 4 rates here are much lower. The best I have seen is from Tesco (o2 network). Low cost no frills service. 750 minutes + unlimited texts + 1gb of data per month. Also, incoming calls do not charge minutes. 1 yr. contract 32gb iPhone 4 = £299/$450 + £35/$50 per month (all tax included). After 1 yr. they have to unlock your phone. After you unlock the phone you can drop down to £20/$30 per month.

    This means the 2 year cost of the phone + service in the UK is £959/$1,438. In the US the 2 year cost is $299 + tax and $105/mo + tax. Total cost over 2 years is $2,819 without tax.

    As you can see the UK has much lower price over the 2 years. Plus, after 1 year you 'own' your phone and can resell and buy iPhone 5.
  • strikeback03 - Tuesday, July 6, 2010 - link

    I think the unlock on AT&T can be requested after 3 months, definitely after a year as I had a friend do that.
  • StormyParis - Saturday, July 3, 2010 - link

    I've abandonned data plans, and switched back to plain voice, on my HD2. I get Wifi most everywhere (at home and at work for sure, and most places in between). I was simply not using data that much, it's not worth the monthly 30 euros they want for it.

    99.5% of the time, there's no difference at all. 0.5% of the time... i can survive...
  • vol7ron - Wednesday, June 30, 2010 - link

    I agree, but...

    "The fact that Apple didn't have the foresight to coat the stainless steel antenna band with even a fraction of an ounce worth of non-conductive material either tells us that Apple doesn't care or that it simply doesn't test thoroughly enough. The latter is a message we've seen a few times before with OS X issues..."

    Apple would just see this as another selling point for the bumper.

    Anand/Brian-
    I'm curious if you've had a chance to test with the microfilm covers like Bodyguardz or Zagg.

    I use these because of how thin they are and how great they are at protecting the device (scratch free even when dropping on concrete). They cover all points of the phone rather effectively. I'm curious if they would be beneficial to your testing.

    vol7ron
  • Brian Klug - Wednesday, June 30, 2010 - link

    vol7ron,

    You're totally right, I need to test with a thin film or some heavy duty tape/invisible shield. I originally thought of doing that, but somehow it got lost in all that frenzied testing. I'll whip something up and see if anything changes. I mean that's a good point too, it might not do very much.

    I mean, ultimately there's a thickness you do need to achieve, and to be fair a lot of the benefit the case adds is that extra couple mm or two from the antenna. If the film is too thin, it might not do much. What makes me uneasy about saying anything definitively is that this is so near field - literally on top of the radiative surface. I'll admit I have only a basic level of understanding about what kind of interference happens in the very near field. I mean even at 1.8 GHz, one wavelength is 16 cm - the case and your hands on the phone is way inside near field.

    -Brian
  • rainydays - Wednesday, June 30, 2010 - link

    Agree. Outstanding review. The detailed analysis and level headed tone is excellent. Keep up the great work.

    Antenna section was illuminating. Good point about using SNR. I wonder if that number by itself is sufficient though. I guess signal power in dbm along with SNR would give the most complete picture of reception.

    At any rate, as is abundantly clear in the article, you never really know where you are till you see the numbers.
  • John Sawyer - Thursday, July 1, 2010 - link

    Yes, the numbers, details, etc. are more important than a lot of people realize. It often annoys me when I see people commenting about issues that involve actual measurement, technical facts, etc., without referring to any of those, and thus winding up with all kinds of conspiracy theories, bogus suggestions, etc. As applied to hardware problems from any manufacturer, generally many such commenters, in their understandable desire to just see a fix for a problem, wind up suggesting the only important thing is for the manufacturer to set up a return exchange program, which would be nice if it were always that easy, but it doesn't address the details of the problem that are often quite interesting, and can be very useful for people trying to learn from the situation.

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