Mac & Bluetooth audio

Mikey23 · 25-08-2014 3:56pm #1

I bought some bluetooth speakers recently that I'd long coveted - the Harman Kardon SoundSticks Wireless Speaker System. I was initially delighted with the sound - much better than the built-in speakers (my old iMac seemed better than this newer 'skinny' Mac in that regard).

One irritating issue however is when I'm not playing music or listening to podcasts. There's a sporadic 'popping' noise, as if the speakers are disconnecting and reconnecting. If I'm working and frequently switching applications or windows, it seems more common.

Web searches have thrown up suggested fixes involving 'com.apple.BluetoothAudioAgent', which doesn't seem to exist on Mavericks. Anyone have any ideas?

(I'd have resorted to plugging them into the headphones port if I could, but the leads are short and the subwoofer would be pretty much under my feet and likely to get damaged).

I've a recent iMac (27-inch, Late 2012), OS X Mavericks (10.9.1), 3.4 GHz Intel i7, 3 TB Fusion Drive.

I've posted this query on the Apple boards without reply. Apple tech support sent me out Harman Kardon's way, who have sent lots of emails with such useful tips as 'try using it with non-Apple devices' - perhaps implying that there's an issue with Macs that they they won't tell me.

Sad Professor · 25-08-2014 4:33pm

I think BluetoothAudioAgent may have became just com.apple.Bluetooth.plist in Mavericks.

What band is your wireless network? 2.4GHz? I ask because your Mac’s Bluetooth might be suffering interference from the Mac’s WiFi. They are both on the same chip and don’t play nice together in my experience, especially during high network activity. It might be worth getting a Bluetooth dongle and see if that resolves it. Or (if you can) switch your router to 5 GHz.

If its a Mavericks issue it may be resolved (or exasperated) in Yosemite.

Greentree_uk · 25-08-2014 6:30pm

try updating to 10.9.4

Mikey23 · 26-08-2014 9:31pm

Sorry, typo there - running 10.9.4 alright.

Our WiFi is on 2.4GHz band but we've little choice - our UPC Horizon box doesn't support 5GHz unfortunately.

I'd the Bluetooth Explorer Event Log running this evening while I was working: each of these seems to correspond to a noise:
2014-08-26 20:25:26 +0000 Mode change 11 for handle: 0x2
2014-08-26 20:25:29 +0000 Mode change 14 for handle: 0x2
2014-08-26 20:25:30 +0000 Mode change 14 for handle: 0x0
2014-08-26 20:25:35 +0000 Mode change 14 for handle: 0x2
etc

Sad Professor · 26-08-2014 9:37pm

Try turning off your Mac's WiFi for a while and see if the problem remains.

Mikey23 · 27-08-2014 10:42am

Will do. Will give it a few hours this evening.

Mikey23 · 29-08-2014 3:20pm

No joy - problem still occurs with Wifi off and with my phone - only other internet-enabled device nearby - on airplane mode.

My keyboard & mouse are bluetooth devices, and work reliably. Seems like the Soundsticks themselves are the culprit.

Worst yet is that I've now hooked them up via the headphones cable and they're nagging me ceaselessly to connect via Bluetooth. Grr.

Greentree_uk · 29-08-2014 4:38pm

perhaps a bandwidth issue? have you tried a cabled keyboard and mouse?

Mikey23 · 05-09-2014 10:57am

Thanks for that. The article describes the problem far better than I did.

Just looked at the contents of com.apple.BluetoothAudio.plist hoping to find Bitpool values but no joy. I'll make a copy of it when I get home this evening and experiment a bit.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Previous Input UID</key>
<string>AppleHDAEngineInput:1B,0,1,0:1</string>
<key>Previous Output UID</key>
<string>AppleHDAEngineOutput:1B,0,1,1:0</string>
</dict>
</plist>

Mac & Bluetooth audio

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