This is a common problem with entry-level digital keyboards. The low cost of a voice-sampling chip makes it possible for manufacturers to include hundreds of decent instrumental sounds, but the onboard speakers haven't been upgraded as well. The top synthesized sound generator is still going to sound tinny or distorted when played through a low-quality speaker.The best solution is to look for an outgoing RCA or headphone jack and run the keyboard through an auxiliary input in a home stereo system or use a bass or keyboard amplifier.