If it's Sonique 2.0, it's still in Alpha last time I checked, which means it isn't going to run very well.
Try foobar2000, great audio quality and uses virtually no system resources.
I'd recommend the following settings...
Under Playback, select 16 bit fixed point and strong ATH noise shaping.
Under output, select Kernel Streaming.
One thing you forgot to mention is your system specs, the most important being your audio card. Kind tough to help if we don't know what you have, what OS you're using and what version of Sonique.
P4 2.6C, Thermalright SP94/Panaflo 92MM M1A, IC7 Max3, Swifty MCX159, 1GB Geil PC4000 Ultra Plat, Radeon 8500, Audigy 2, 2X WD Raptor RAID 0, WD 250GB SE, Plex 708A, 166SDVD, LianLi PC75, XP Pro.