How to get quad sound for a PM 4.1 using a Mac with 1 stereo out?

[shmerls]

Does any one have any insight into how Klipsch expected the average computer with just a stereo output to create 4 channel sound? I realize the subwoofer or .1 of the 4.1 on, in this case, my ProMedia 4.1 is created within the Klipsch system.

But what about the 2 front and 2 rear speakers? How are we supposed to get quad sound?

I bought my PM 4.1 new and use a Mac Pro tower, which only has a single stereo headphone out jack.

In order to have the "semblance" of surround sound, I merely "Y" jack the 2 PM cables together and thus get the same left audio in the front/left and rear/left and same right audio in the front/right and rear/right.

But in the old days, a company called Creative Sound Labs made a sound PCI card for the Mac (and PC too), which had front and rear out jacks and software, which I assume artificially created 4 discrete audio signals to make the quad signals. They no longer make cards for the Mac and neither does anyone else, so unless some one knows something, the only solution seems to Y jack the front and rear PM cables together to get a pseudo surround sound by virtue of speaker placement.

Any one know what Klipsch originally had in mind? Any ideas on what to do with a quad Klipsch system when you only have 1 stereo output?

My Mac also has a digital audio out, but I don't know if it is stereo, 4.1, 5.1 or 7.1. Not that it matters since the PM is analog, I guess.

Thanks,
Steven