USB Headset: Gets sound from Computer (eg. iTunes), but not from Microphone

That moves me into unfamiliar territory, so, I have attached a photo the Audio Devices MIDI window.

On "Ch"annel, I suppose the "1" and "2" speaker slidebars are supposed to be greyed-out?

Do you see any obvious problems.

Oh, and thanks for your reply—much appreciated.

BDAqua—

I removed Soundflower. In learning how to do that, I saw an association of it and Audio Hijack Pro ... a program on my computer. So, I opened it and — here's the weird thing which I hope might be a clue toward resolution — when I activate Hijack Pro, I can hear myself in the headset. [see pic below] PROBLEM: it sounds a bit like an echo chamber.

Does this info lead to further suggestions. Many thanks.

UPDATE: LineIn a no-go

It was recommended that I try a software fix: LineIn (freeware program Rogue Software). The software does allow the mic audio to be routed through the headset… UNFORTUNATELY, it does so with a severe echo (delay). My goal, of course, is to get the headset to play as it originally did: good quality mic sound, played thru the headset.

Thanks for the comment, BDAqua.

ADDITIONAL DATA: The same phenomenon occurs when I hook the headset up to a brand-new mini-Mac! The headset is the first thing I installed—and still it won't work properly. One thing I know: I can't blame any 3rd-party software: it's a MAC — Logitech thing.

UPDATE. Earlier, I narrowed the problem down to a Logitech—Mac interface problem (i.e., problem not caused by 3rd party software). Now, I have narrowed it to a Mac problem. How? I borrowed a Rosetta Stone USB headset/mic, and guess what: same problem as with the Logitech headset/mic. So, that's two working headsets on two different Macs (one of those being brand new), and the same problem. The only common denominator: MAC's fault.

In light of that, if anyone has a Mac fix for this, it would be greatly appreciated. I'm hoping some wizard-of-smart will have a TERMINAL line of code, so some other non-obvious fix.

For someone just joining who doesn't want to read the previous notes, all System>Sound and Midi Audio Devices are set correctly. The only suspicious thing there is that the "Thru" selection boxes on the Midi Audio Devices are greyed out. (Thinking out loud, "Man, if I could just check the Thru button, I'll bet the sound just might pay "thru" the headset. Hmmmmm. LOL)

Thanks in advance

DISCUSSION WITH APPLECARE

I was just on the phone with AppleCare for 1 hr and 3 min; up to the AppleCare senior Advisor level. I clarified with them several times what I am about to tell you now, informing the advisors that I planned to report what they said to this board.

In short, Apple outright stated, as far as they can tell, that a Mac is NOT equipped to allow a Logitech wireless/bluetooth headset nor a direct-USD Rosetta Stone headset to play a mic through the headset. (Their marketing department should love that one.)

I made the remark that the Logitech H800 headset did, in fact, play through the headset for a day! —but never after I rebooted after that first time. I was continuously nudged, of course, to the idea that is was the headsets fault, but the fact that the Mac did play “thru” once-upon-a-time somewhat nullifies that argument. Also, the headsets do NOT require their own software, which eliminates “driver-type” issues. (I will give AppleCare credit in that they didn’t waste an hour having me re-preform all the obvious ‘System > Volume’ and ‘Midi Audio Device’ gyrations; and they did, with only a little prodding, move the case up the support ladder.)

I told the advisors that the 3rd party program “LineIn.app” DOES allow the mic to play thru the headset, but it does so with an echo. And speaking of play thru, I pointed out the fact that the MIDI controls do come with a “Thru” option, but that the option is grayed-out, seems like the culprit. My suspicion is that if I could just click on the MIDI ‘thru’ button, the mac would do for itself what LineIn.app tries to accomplish. I'm sure the "thru" option was not placed there for good looks.

Here’s where it stands. I have a case number, and AppleCare is checking with their hackers to see if some (my words, no theirs) switch has been changed from TRUE to FALSE, or from ON to OFF somewhere in the software preferences. And the electronic switch has caused the "Thru" option to become grayed.

For those of you interested, I will advise on how things develop from here.

Tried DBAqua Suggestions (previous reply)

Those ideas did not work, but thank you for your effort. Here's my report:

• Open new Admin User "headphone"
• Deleted the 1st .plist file you mention (the second one did not exist)
• Restarted computer
• Result: nothing changed: everything works EXCEPT mic-thru-headset. The 'MIDI device thru' box still grayed-out; and Prefs>Sound shows all is connected correctly.

Will advise if and when I hear from AppleCare. Until then, all suggestions welcome.