Hi,i'm using a Yamaha sw1000xg soundcard with 256ddr ram and an XP1600 processor.Problem is the song im working on at the moment has 4 audio tracks,now say i solo stereo pair tracks 3+4(bass guitar)and stereo pair 9+10(distorted lead guitar)together there is crackling,but listening to each of these stereo pair tracks individually there is no crackling?If i solo stereo track 3+4 bass guitar(all other tracks muted) then unmute 9+10 the crackling starts and the bass guitar track deteriates in quality?Its just when i play the tracks together?Hope ive explained this ok.All midi is fine incidentally,does anybody have any vague idea what's going on or where to start looking?It's driving me mad!