unintuitive USB Logic

[aeronautical]

Gentlemen:

I have a brand new Behringer X1222USB. I am trying to use it to mix down into Sony Vegas.

Anyway, It has two pair (L&R) of RCA jacks that are labeled: 2-Track/USB (one set is IN and the other set is OUT). I would think the USB IN's would show up eventually on the Main Mix OUT XLR's, which it does. HOWEVER, it does not show up on the USB at the computer OR the RCA OUT jacks. I can hear its (RCA IN) source on the phones which is Main Mix, and also it is controled by the 2 track fader. I asked the techs at Behringer and they said the RCA IN's were not connected to the USB. Behringers literature said the USB line is the same as the Main Mix OUT. Clearly this cannot be. Does it have anything to do with the fact that the USB connection to the computer is bidirectional?

Does any of my learned colleagues out there have any idea why this would be...that the USB out and RCA out wouldn't get signals from the only RCA inputs on the board? What purposed would it serve?

Thanks

[Boswell]

We've discussed the shortcomings of the design of this particular series of mixers a couple of times recently in these forums. The USB interface is bi-directional, but the way that series of mixers is designed makes them unsuitable for tracking, i.e. playing one stereo track via USB out of the computer into headphones while recording the main output of the mixer via USB into the computer.

About the only use for A-Design like that would be in a live situation where you could play recorded music from the computer to the main venue loudspeakers while setting up the rest of the desk for the next live act, then switch over to PA and recording of the live band when they were ready.

[aeronautical]

Thanks Boswell. And that makes sense. They could add one little switch and have it either or. Oh well, it's a small issue...I can always use the line-ins for getting a stereo source into my computer.

Thanks again