I never heard of this product, but I am not convinced. It is quite an expensive addon and the text doesn't say if it is using "sound cones", which I think would be the state of the art sound technology in FSX.

I think if it was using sound cones (e.g. to adapt the sounds depending on if you are standing in front or behind the aircraft or closer to the engine or the prop), they would advertise this in the product text.

Opinions vary on this one. I don't have it, and made that decision based on the meager bits of information I could garner on the internet.

The product's home page makes this assertion:

By default, sounds in Flight Simulator X comes registered by Microsoft at 22,050 kHz using only one channel (MONO). Sound Environment X converts all sounds using two channels (STEREO) at 44,100 kHz. The result is a more accurate effect for every sound available in Flight Simulator X and Flight Simulator X Acceleration Pack.

That can be found at
http://simulshop.com/product_info.php?products_id=434
On that same page is a demonstration waveform picture showing the results of converting a mono file (the top one) into stereo (the bottom one). Look closely at the two streams and see if you spot any difference between the left and right channels (red and blue lines).

It is demonstrably false to say that all FSX sounds are mono and are only at 22,050 kHz. Just look at the properties of some of the large files in your sound subfolders and you'll find plenty that are already stereo at 44,100 kHz. Plus, one of the great features of FSX is its support for stereo surround sound, already built in, 5.1 and even 7.1.

Here are the only two threads I could find actually discussing the product
http://forums1.avsim.net/index.php?showtopic=7389
http://forums.flightsim.com/vbfs/showthread.php?t=187503

It is pretty basic to know that two audio sources are required for true stereo. You can't fabricate real stereo from just one mono source. Whether you can fool the ear by making two slightly different copies of the same mono file is, I guess, a different question, but I don't see two different streams on the product's home page charts of the file they say has been modified.

That's really the extent of available information, so the decision's up to you. If you really want to pursue the matter, I'd suggest sending PM's to the people who state in those threads that they have purchased the product, and ask your question directly of them. Neither Vic Baron nor Bart Bartholomay is shy, to say the least.   Plus, you've now got the opinion of skoker, who has used the product.

Umm....

Am I the only one who uses headphones while playing and hear's it in stereo anyways?

   I bought it just for fun. There's a slight difference in the sound from the cockpit when you turn your head, but nowhere near worth $32. My opinion - save your money.

Blue Sky Wishes,

Dave