duplicate l/r to ls/rs

Diy and Tweaks Diy and Tweaks
1

hello
i have an 5.1/7.1 audio card hookup up to the rpi3 and volumio.
how can i configure the asoundrc to duplicate the l/r output to the ls/rs output?

seems that ttable will be the solution, but no idea of how to configure it.

thanks