Does anyone know how to connect a consumer headset mic, in particular an Audio Technica ATH-AG1 to a professional interface, in particular a Focusrite Scarlett? I've tried with a 1/8" to 1/4" adapter and there is just nothing on the input, it shows no sound.
 
I realize this is a strange thing to do, wanted to see if anyone here had any advice?

Which Scarlett are you using? If it is a version with MixControl, it is possible there is nothing routed to the headphone monitor.

It is possible that your 1/4-1/8 adapter is bad.

You need to split the mic from the headphones (two jacks). Other way is to plug into internal sound card and route that into the saffire.

Haven't one of these myself, but looking at AT's website there's several issues here.

The 1/4" inputs on the Focusrite are intended for "line level" input which is many times higher than a mocrophone puts out. So one reason for no sound is that a line level input hasn't got enough gain to raise the signal to a usable level. To do that you need to connect to a microphone pream, which are the XLR sockets.

Another reason is that the headphone's lead has a plug that handles stereo audio to the headphones and mono audio from the mic. The Foxusrite line inputs will take "stereo" type jack plugs, more accurately called TRS (Tip/Ring/Sleeve) for a balanced input connection or a "mono" (TS) plug for an unbalanced connection those plugs aren't compatible with the connections the plug on the headphones has. Which, for the sake of completeness, is a TRRS one if I've counted correctly.

The mic is also a condensor type so unless it has batteries it will need to get sent the right electrical DC voltage in the right connectors to make it work (called "phantom power"). Which could be anything from a few millivolts to quite a lot more than that, and sending it too much voltage will quite probably kill it so best not to go there.

You might well be able to get it to work with a PC's on-board sound using the Y adaptor cable AT's site say it comes with but interfacing it with the Focusrite would be far from simple.

AT say the headset comes with a miniature USB DAC. It should work plugged into the PC using that and Sonar (or any other DAW) should recognise the DAC as an available audio interface so long as any necessary drivers have been installed. The results might not be as good as the Focusrite and monitoring latency might be a problem (unless AT happen to supply ASIO drivers for it), but will quite possibly be better than the PC's built in sound.

In all honesty though if you want to record singing or even voiceover your better option would almost certainly be to pick up an inexpensive mic that uses an XLR to XLR cable (there are quite a lot of cheap "USB" mics that use USB cables direct to PC - avoid them) and a seperate pair of headphones (or monitors) if necessary.

This isn't for recording, this is helping a friend. He wishes to use a Scarlett 6i6 as his audio interface for Windows since it has nice headphone features and the ability to mix in an external source (a TV in his case) and to use the mic for voice communications in games.

I would simply use a set of headphones and a cheap dynamic mike for gaming. Use higher quality models for recording or listening to music.

OK, if that's the intended use you could try using the AT Y splitter lead. Put a mini to 1/4" stereo jack adaptor on the headphone plug and connect to the Focusrite. Plug the mic minijack into the PC soundcard.

Then use the ordinary Windows drivers (which is what Windows, games and media players will be doing anyway), with Window's sound mixer set up to use the Focusrite as audio output and the onboard sound as input.

Might or might not work, but very cheap to try as all it needs is one mini to 1/4" stereo headphone adaptor.