The current model is the 1124, while the 1100 is an older discontinued model. The 1124 operates the exact same way as the 1100, and is pretty much identical except that it uses higher resolution 24-bit DACs, whereas the 1100 uses 20-bit DACs. If you plan to use the unit for subwoofer equalization, both units will do the job equally well. The 1100 supposedly introduces audible noise into the signal, but that starts well outside of the bass range.