pkg://x11amp-0.9_alpha3-6.src.rpm:533013/README.ESD  info  downloads

                                X11AMP for Linux

Red Hat's version of x11amp require the use of 'esd' (Esound dameon).
When starting GNOME, this is done by default and shouldn't be a problem.  
However, if you wish to use x11amp without using 'esd' you must choose the 
OSS plugin that can be selected in the preferences of x11amp.  Applications 
that use esd should fall back to /dev/dsp, but the fallback is currently not 
working.