Apple's iPhone 4: Thoroughly Reviewed
by Brian Klug & Anand Lal Shimpi on June 30, 2010 4:06 AM EST- Posted in
- Smartphones
- Apple
- iPhone 4
- Gadgets
- Mobile
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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macmanitou - Monday, July 5, 2010 - link
Hi Brian,great article, but one question just pops in my mind looking at the signal attenuation table, is the iPhone 3GS really the best? If yes I should really stick to it and probably just cancel the iPhone 4 order ;)
Sascha
isotropic - Monday, July 5, 2010 - link
Posted by: isotropic | 07/5/10 | 5:01 pm |This link Shows a Test phone TEMS sony/Ericsson K800i test phone (cost 2500+ Euro) being given the grip of death. A test done in a few minutes. It shows at a given point up to 16 dB losses by being held tightly as I have seen people doing it on the new iPhone. Not saying the iPhone could not have a problem, I don’t own one. But the iPhone is not alone for sure on this one. And Apple’s latest explanation seems pretty valid to me
http://www.youtube.com/watch?v=OWpGOxyEoZc&fea...
Akv - Monday, July 5, 2010 - link
I don't mind being locked in the Apple network for my iPod, because I find iTunes a quite convenient solution. However for a professionally strategic device like my cell phone, I would prefer a more independent solution.Besides, I still think it doesn't bring enough for the price. I could buy an excellent netbook for less than that price, and I would still have some money left for a simple but efficient clamshell phone.
ifartinyoutdirection - Monday, July 5, 2010 - link
It is a featurehttp://henriko.se/extern/iphone4buttonsandcontrols...
davehutch - Tuesday, July 6, 2010 - link
Your screen captures don't actually reflect what is being recorded. The video capture screen is a full-screen version that is not showing the correct ratio. the screen should be double-tapped for a tru representation and yes, the video angle of view is indeed smaller than the still image angle of view.please see my post here:
http://forums.macrumors.com/showpost.php?p=1044575...
for additional screenshots and comments.
r2d2droid - Tuesday, July 6, 2010 - link
Interesting. . . but I still want a droid.estarkey7 - Tuesday, July 6, 2010 - link
Why didn't you use Sprint's Everything plan pricing? For $99.00+$10.00 for the Evo 4g tax you get unlimited EVERYTHING, now add in tethering and see where that brings Sprint in comparison with AT&T and Verizon.Different ballgame all together, because 900 min is nothing. I talk 1200+ every month.
RadioGuru - Tuesday, July 6, 2010 - link
Hello guys. Thanks for the review. I have a quick question. Your wrote that "To generate these numbers, I measured at least 6 times and took the average"I wonder, did you convert the dBm number to linear, took the average and the recalculated the numbers back to dBm, or took the average using the dBm values. If you did the later, the numbers are completely wrong.
Your testing is better than most of what I have seen online so far, but real engineering testing has revealed that the TIS (Total Isotropic Sensitivity) of iPhone4 in Free Space is better than the 3GS, which is great!!!! but.....and here comes the big but....phamtom head testing of WCDMA 1900 TIS/TRP spec testing has shown a degradation of close to 30 to 40 dB in chamber testing. Which means a controlled lab environment...not a cowboy lab testing like the one you used. Sorry, I respect your work and I support what you do...but this time of evaluation requires far more engineering power.
in WCDMA/HSDPA systems, a call dropped is usually driven by reverse link limitaiton. Therefore engineers also consider TRP (Total Radiating Power) to measure antenna performance. in the case of iPhone4, TRP degradation due to HAND+HEAD is close to 40 dB, which will kill the call or increase drop calls or reduce data througput performance.
By the way, BAR maping using SNR makes sense for HSDPA data calls. GSM calls should use RSSI.
jacobdrj - Thursday, July 8, 2010 - link
You rock.dalebeal - Friday, July 9, 2010 - link
This is the most comprehensive review I have read - and I've read a lot of them. Thank you!