[cwell2112]

It's been quite a while since I last posted, but I'm in need of some advice.  I recently purchased a Sennheiser PC360 headset to use for Xbox gaming.  I'm fully aware that the PC360 is designed for PC and not console gaming, but I figured I'd at least try to get it working, since it's a very good quality headset.  So far audio is working as expected.  I have the Xbox putting out line level audio into my Little Dot MK V, and I have the the PC360's headphone connection plugged into the amp.  The issue I'm having is with the microphone.
 
The PC360 microphone plug is a standard 3.5 mm plug, and the Xbox microphone input is a 2.5 mm jack (on the controller).  The only thing I've tried so far is plugging the microphone directly into the controller via a 3.5 mm to 2.5 mm adapter.  When I first fired up the Xbox and connected the PC360's microphone, everything worked fine.  The icon popped up to indicate I had connected a microphone, and my voice was coming through loud and clear in voice recordings and in-game.  I played a few games of Call of Duty, and had no issue with the mic.  I then turned off the Xbox and unplugged the mic.  I came back later and fired everything up again, and now the Xbox no longer detects the PC360's microphone.  Here are my observations:
 
-With the Xbox running, controller turned on, plugging in the PC360 mic via adapter does nothing.  The Xbox does not detect the microphone.
 
-Plugging in only the adapter (with microphone unplugged) causes the Xbox to detect a microphone.  The icon pops up to indicate a mic is plugged in, but of course no voice will come through since the actual mic is disconnected.
 
-With just the adapter plugged in and the Xbox indicating a mic is connected (as above), plugging the PC360 microphone into the adapter causes the microphone icon to disappear, as if I had unplugged the microphone.  Note that I tried this with two different adapters, and observed the same behavior with both.
 
-Other known good headsets with 2.5 mm plugs (including the one which came with the Xbox and two that did not) all work fine.  Unfortunately I don't have another microphone with a 3.5 mm plug to test with the adapter.
 
-The PC360 microphone works fine with my computer (as it should).
 
So, that's the behavior I've observed, now the goal is to explain it.  I think that from what I've seen, I can safely say none of the components are defective.  I tried swapping out controllers, headsets, adapters, and recording devices (PC vs. Xbox), and each independent component appears to be functioning.  There just seems to be a compatibility issue between the PC360 microphone and the Xbox.  What I'm trying to find out is what could this compatibility issue be, especially considering the mic worked great for a couple of hours?
 
One possibility is an impedance mismatch between the PC360 microphone and the Xbox mic input.  This could be, but I doubt it's the issue.  The Sennheiser technical specs indicate a microphone impedance of 2k Ohms, with a sensitivity of -38 dBV/Pa for the PC360.  Now, they also make two headsets marketed specifically for the Xbox.  One of these has a microphone impedance of 2k Ohms, sensitivity of -40 dBV/Pa, the other 2k Ohms, -38 dBV/Pa.  Perhaps there's something about these specs that's lost on me, but it certainly appears impedance mismatch is not the issue.  And anyway, wouldn't the impedances have to be grossly mismatched for the microphone to not work?
 
Another possibility is the contact order on the PC360 microphone plug is not the same as the contact order on the Xbox microphone jack.  Perhaps the microphone contact on the PC360 plug is the tip while the Xbox jack is looking for microphone voltage on the middle band.  One would think both companies would follow some standard on that, but I wouldn't put it past Microsoft to flip the contacts just so that you need to buy a mic specificially designed for the Xbox.  Again, though, I don't think this is the issue, as the microphone was working beautifully for a while!
 
I'm hoping someone here might know a little more than me about microphones and their compatibility with the Xbox.
 
One possible solution to this whole issue (or a workaround, depending on how you look at it) is to purchase an Astro Mixamp.  I've read of several people using this with the PC360's, and it does have a microphone output that's designed for use with the Xbox.  It would have the additional benefit of independent game and voice volume adjustments, but I'm guessing the headphone amplifier is not nearly as good as my Little Dot.  Perhaps that doesn't matter so much for gaming.  Opinions on that option?

 

[cwell2112]

No thoughts on potential causes?  I've contacted Sennheiser and Microsoft regarding this issue, and neither was helpful.  Sennheiser won't acknowledge it as a legitimate problem since the PC360 is not designed specifically for use with the Xbox.  Microsoft just told me to contact the manufacturer of the third-party headset.  It seems with this type of issue, contacting tech support is just running around in circles.
 
I've done extensive searching on the internet for other instances of this issue, and found very few.  There are many people saying a simple adapter will allow the PC360 mic to work with the Xbox.  I've found a couple of cases of people claiming to have problems with the PC360 mic through an intermediate device, such as the Astro Mixamp or the Tritton AX720 decoder.  I've gathered that there are also many people using the PC360 with these devices (the Mixamp in particular) on the Xbox with no issue.
 
I have an Astro Mixamp on the way, so we'll see if placing that between the microphone and the Xbox resolves some kind of compatibility issue.  (As an aside, does anyone actually know what goes on in the Mixamp between the Y adapter microphone input and the 2.5 mm microphone output?  If those two are just hardwired together, I'd expect the exact same flaky behavior with and without the Mixamp).  If the Mixamp doesn't work reliably, I suppose I'll just cut my losses and get a different headset.  As much as I like the PC360, it's not worth the frustration of having a microphone that I'm never sure will work.

 

[chicolom]

I've had the exact same problem with my PC360s trying to run them directly into the controller.  They worked for a bit, then stopped and nothing I tried to do could get them working again.  I don't know what caused it. 
 
I didn't really pay it any attention, because this was just a one-off occasion as I always use my PC360s with an Astro Mixamp. 
 
The mixamp should fix it for sure.  I'm not sure whats in the Y-adapter, but it always works.  I think the mixamp does something with the voice audio before sending it into the controller.  Not sure, either way I've never had it mess up unless the 2.5mm male to male cable itself is faulty. 
 
I think the mixamp will solve all the issues and the PC360s should start working as intended.  Plus as an added benefit you get surround sound!

 

[cwell2112]

Excellent, thanks for the reply.  That gives me a lot more hope that my PC360s will work with the Mixamp.
 
I actually ordered the Mixamp primarily to try to get the microphone working, and secondarily for the voice/game balance adjustment (since chat is virtually impossible to hear in MW3 when the game gets even a little bit noisy).  I didn't know what "Dolby Headphone" was and figured it was a gimmick that I wouldn't use.  The more I read about it, though, the more excited I've become.  It really seems like a significant improvement over standard stereo audio for FPS gaming in particular.  I'm eager to test out the Mixamp and see if the Dolby Headphone HRTF is a good match for my ears/brain.
 
Once the Mixamp arrives, I'll be sure to report back on how it works with the PC360 mic, and what I think of the virtual surround sound.  Unfortunately, I have to wait another week before it gets here, since I went with cheap shipping from California to Massachusetts.

 

[cwell2112]

Okay, so I received the Astro Mixamp yesterday morning, and I've been playing Call of Duty all weekend with the PC360/Mixamp combo.  I've had no issues with the mic now that I'm using the Mixamp, so that's good news.
 
I'm still developing an opinion on Dolby Headphone.  I was quite impressed when I first turned on my Xbox and flipped around the dashboard how the scrolling noise seemed to be coming from the screen instead of inside my head.  Another "wow" moment is calling in Predator missiles.  Right after the missile hits its target and my character closes the laptop, I can hear the tail end of the explosion, and it truly sounds like it's coming from across the map.  It's really an awesome "out of head" sound.  Overall, the virtual surround was very strange sounding and reverby at first, but I became accustomed to it after about a dozen games.  There have been a couple of instances where I could not tell whether a sound was coming from the front or the back, but in other cases that distinction was very obvious.  I guess time will tell if this is an issue or not.  Either way, I think Dolby Headphone is a significant step above normal two channel audio for gaming.
 
While the sound localization is great with the Mixamp, I can't say I'm playing better than I was without it.  When I started playing Black Ops with my HD650s instead of my (pretty good) speaker setup, I really did instantly become a better player.  Dolby Headphone wasn't as big a leap, but it's better, and I don't regret throwing down the cash for the Mixamp.