After a tremendous amount of support time of my own with theBoom and Apple, it is clear now that Apple OS X Mountain Lion is incompatible with some third party 3.5mm jack microphones.
Here’s the problem: I have a theBoom v4 microphone that worked great in Mac OS X Lion but it will not work in Mountain Lion. Even when my theBoom v4 headset is plugged in, this is what my Sound Preferences Input tab looks like:

theBoom technical support returned my call and confirmed the problem with MacBook Air laptops. I have since tested on 10 MacBook Airs (all units on display at an Apple Store), MacBook Pro (non-retina and retina models) and all have the same problem.
Additionally I’ve tested with associates’ Apple laptops. The only two cases with Mountain Lion that recognized “External microphone” were early 2011 MacBook Pro purchases of friends, so it appears to be a combination of newer hardware + Mountain Lion that represents this problem. Incidentally, my iPhone 4 headset works fine everywhere (but it’s a terrible microphone).
I called Apple Support, who referred me to a Genius, who referred me back to AppleCare. At the second call, AppleCare listened and provided me with a case number, senior advisor name & extension and he suggested it would be a driver issue to be supplied by theBoom and included in a future software update by Apple.
Normally I wouldn’t make a big deal out of an incompatibility like this, but this has left me with only the option of downgrading back to MacOS X Lion. I require both USB ports for other purposes, so a USB headset is not an option. Even though I carefully checked for 100% of my must-haves to be compatible with Mountain Lion before the upgrade, I’ll listen to my own advice to our clients – to wait until the first major update to a new Apple Operating System upgrade.
That’s my “confession of a leading edge junkie” today.
UPDATE#1 (2012-08-23): The MacOS X Mountain Lion Update (10.8.1) did not solve the problem either.
UPDATE#2 (2012-08-28): After downgrading to MacOS X Lion (10.7.4) on this same MacBook Air, the microphone is still not recognized. Therefore a hardware AND software problem.

UPDATE#3 (2012-09-20): After Apple’s MacOS X updates (10.7.5 and 10.8.2), still no joy 🙁













or 
I use a 3.5mm TRRS – XLR f + 3.5 TRS Headphone adapter with a Lo Z dynamic mic on the XLR. I’ll take the rig to an apple store and see if it works on display units there.
Is it the same device that stopped working with a mountain lion upgrade? (I am still using 10.6.8 and am hesitant to upgrade).
It’s really a great and helpful piece of information. I am satisfied that you just shared this helpful information with us. Please stay us up to date like this. Thanks for sharing.
@Larry Robbins: That’s correct. The same device that worked on 10.7.4 stopped working after upgrading to 10.8
Just curious, did you find a fix for this? I can’t understand how the Macbook w/ Mountain Lion manages to see two seemingly identical TRRS plugs differently.
If I just get a macbook from Bestbuy does it need fixing and stuff like that or just take it home and just start playin around with it?
Where you purchase it won’t matter, it’s still made by Apple with the same manufacturing details.
I have the same problem with a Logitech G330 headset. It just doesn’t work with Mountain Lion on a new Macbook Pro Retina.
Brian, thank you for sharing. I’m not surprised with your news. This has obviously been a problem for some time now, and the lack of information or updates from Apple on this, quite frankly, is disappointing.
Ståle: unfortunately I still do not have a fix – not even yesterday’s MacOS X Updates solved it 🙁
Same here with a ISY Headset -.-
It worked itself out – now every TRRS plug works! I don’t know if it was the latest update or not – my Mac is a mid 2009 MBP.
Who really cares. Apple have a phone that everyone who has one thinks it’s a status symbol and makes them superior and the masses follow like a herd. Anyone who knows anything realises, that with android you have more options, and apple locks you in. Ever tried copying your songs from a Iphone to a non iphone…it’s a pain if you know how and impossible if you don’t. Try that on an android or windows phone it’s very easy…thats just an example.
Hi,
The rMBP’s combo connector does switch to external microphone with the current iphone headset (test with the one that came with iphone 5).
Unfortunately a simple TRRS splitter cable does NOT do the trick! What makes that headset so different? What makes this combo connector switch?
Thank you for all this brilliant information. I look forward to have some news. Bought a new Retina and I’m having the same issue with 10.8.2. Hope they get it fixed soon!
It’s a hardware problem. on the 3.5 mm jack of the iPhone and in the port, ground and microphone pins are swapped. But there is an adapter for it:
http://www.adaptare-shop.de/Apple-3-5-mm-Klinkenkabel-4-polig-TRRS-Pinout-Changer-fuer-Headsets/a40265664_u526_zff5b7849-ec7e-4ef3-a6bc-21079d39418e/
(it’s a german shop, i don’t know if it’s available anywhere else). I haven’t tested it, but it swaps the pins, so it should work.
*3.5 mm jack of the iPhone headset
is what I meant.
This is a joke, why have Apple disabled such a simple feature, they had no need to.
They’ve removed this feature with a firmware update, hence any downgrading of one’s operating system will be unsuccessful, the only workaround I can see is replicating what another said earlier; find an adapter which is a duplicate of the iPhone headset’s adapter.
Since I originally published this article I have purchased the TRRS pinout changer from Germany and unfortunately it does not work either. 🙁
I’ve made my own cable, TRRS to one XLR and one 3.5mm. But I need to “activate” the external mic input with a dynamic mic (SM58), then switch to my self powered condenser mic.
I just switched to Mac and issues like this make me SO glad I did. What the heck?!?
Has anyone tried this: http://www.kvconnection.com/product-p/km-iphone-mic.htm
I’ve read in a couple of places that an extra resistor of approx 1 or 2 kOhm is required between the Mic and GND pins of the adaptor or headset, in order for the new MacBook or iPad to recognize it and autoswitch.
This matches up with the post above… a dynamic mic would provide that resistance but a condenser mic wouldn’t.
I’ll try it out and post back… I neeeeed this to work!
Tried http://www.kvconnection.com/product-p/km-iphone-mic.htm with no success. This enables a Rode Video Mic to work with an iPhone, but not a MacBook Pro. Still searching…
According to this post, it looks as though Apple has disabled line in input to the combo port in the latest OS releases: https://discussions.apple.com/thread/4550354?start=0&tstart=0
The Evil Empire just gets eviler…
I have early 2011 MBP 13inch model, and Im getting the same problem.
I am trying to upgrade my os to mountain lion 10.8.2 from snow leopard.
Since it worked before, I’m guessing it’s more of a software problem than hardware.
Have you tried resetting pRAM and SMC?
If upgrading OS doesn’t work for me, I’m going to try resetting pRAM and then resetting SMC.
Try resetting them if you haven’t tried and see if that solve your problem.
FYI: I got this info from
http://forums.macrumors.com/showthread.php?t=1462349
Hi Joe – I have tried resetting the pRAM and SMC and has not made a difference at all for me on my MacBook Air.
Interesting…
You could just use USB splitter and external audio USB adapter?