Practically Agile
Using Agile in less-than-perfect situations since Y2K
IPhone-Bluetooth Audio Skipping Problem
For Father’s Day this year, my family gave me the gift of a stereo Bluetooth headset. I had been asking for one since the iPhone announced support for A2DP headsets. (Basically, simple stereo headphone support.) The one I got was the Plantronics Voyager 855. I can’t speak highly enough about it. There may be sets with better sound or build quality, but I haven’t had any problems with the set itself. And at just over $30 it is far cheaper than most. Listening to podcasts or music while mowing the lawn or whatever else is fantastic. The combination of in-ear buds that block out external noise and the wireless connection to the phone—I can’t believe I lived without it for so long.
However, the iPhone’s Bluetooth support is not the best. I have an 8GB 3G, and had a lot of trouble with the audio cutting out. Worse, the same was true when I was on a call. I could usually hear just fine, but folks on the other end would tell me that my voice was cutting out. I was starting to blame the headset and was preparing to buy a more expensive model.
Fortunately, I noticed two important things. First, the podcast/music audio cutting out tended to only happen when the screen locked. This was true whether or not I pressed the lock or let the phone auto-lock. Second, I noticed that Apple’s iPhone OS 3.1 update mentioned attempting to fix problems with Bluetooth and wireless (Wi-Fi). In their case, they were trying to improve Wi-Fi performance.
Because of this, I decided to experiment a bit. I disabled the Auto-Lock feature and disabled Wi-Fi. Suddenly, I had no more skipping and cut-out problems. People said calls did not cut out either. I tested this way for about a day. I was able to get the audio to cut out by launching a CPU-intensive app, but only during the launch. Once the app was running, the audio came back with no more problems.
After that, I re-enabled the auto-lock. I locked and unlocked the phone. Still no cut-out problems. I then turned Wi-Fi back on. No cut-out problems. Then I locked the phone. Bingo! Audio started cutting out again. I disabled auto-lock, but the problem was still there when I locked the phone. Finally, I disabled Wi-Fi and turned auto-lock back on. No more skipping or cut-out problems.
It turns out that the iPhone is built such that Wi-Fi and Bluetooth share an antenna (presumably to share space). This causes problems when both are on. Apple seems to have found a way to manage this most of the time and even released updates to improve Wi-Fi performance. However, as has been true of iPhone Bluetooth support all along, they seem to have neglected to do the same for Bluetooth. Specifically, something seems to happen to the Bluetooth power (and possibly the Wi-Fi power) when the phone is locked. The combination of signal degredation from both being on and the phone being locked causes the problem.
The moral of the story? If you want to use a Bluetooth headset, disable Wi-Fi. If you want to use Wi-Fi, disable Bluetooth. That will get you the best performance. Now back to enjoying my wireless music while refactoring.
Tags: bluetooth, headset, iphone, problem, wifi
. 02 Oct 09 | Gadgets
I’ve had this problem since I’ve had my headset. I am also using the Voyager 855, but disabling Wi-Fi is not fixing my problem. I attend Auburn University, and I find the problem is the worst is certain areas of campus, and around the neighborhood where I live. I’m thinking it’s because of the multiple wi-fi sources in both locations; I’m just confused because disabling wi-fi has not resolved the issue.
I can only say that it worked for me. I have, since writing this post, had the audio seem to cut out one time when I was not taxing the phone’s CPU doing other things (like loading another app while listening). Since I couldn’t reproduce it, I cannot say what might have been the cause.
I do work and live around multiple wi-fi sources without issue, but I suppose enough EM interference from other Bluetooth devices or other sources could cause problems.
Thanks for posting this! I tried and i was able to use my headphones outside for the first time. However, even with Wifi turned off mine still cuts out if you use a streaming app such as pandora but at least locally stored music plays while I’m working outside.
My firmware is current at version 3.1.3 (updated about two weeks ago) and until yesterday I had no stuttering problems via A2DP to my car stereo. Nothing has changed and all my music is stored on the phone itself.
The stuttering is heavy, and the symptoms appear immediately when the phone autolocks, but disappear just as immediately when the home button is pressed, though the phone is still locked. Basically if the screen is black you can’t listen.
Thanks for posting this as it sounds like disabling the autolock will have me back to normal. If I ever figure out why this problem emerged I’ll try to come back and post.
Interesting
I’ll have to try this on mine it always skips playing music over my bluetooth headunit