Based on that picture your model isn't the one with the best sound, the best one has an FCC-ID code reading FJ846EUSASEGA. Just saying "High Definition Graphics" isn't enough to find a good unit. It could be sounding worse if the capacitors are starting to fail, but most of these systems are still fine as they didn't use cheap surface mounted caps and it's not really that old yet. I've come across several 70's era receivers working fine with the original capacitors, those tend to need replacing now due to aging. You can still try to replace them if you want.