Sound from my Gateway suddenly ''tinny''.

Question

All of a sudden, my music I was playing through my computer speakers sounded tinny and static-like.Didn't change anything or any settings, just turned it on one day and sound was bad. Ran all the ''troubleshooting'' guides and updated all drivers to no avail. This is the second computer (Gateway) that has done this in 6 months. All were purchased together and I've also tried swapping out speakers- it's not the speakers. I looked inside the CPU and there's not an actual sound card- just a little sodered-on box attached to the motherboard.I'm thinking of just getting a cheap USB Plug N Play sound card.Any thoughts?