Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Quality has deterioated

It seems like Coby has started using cheap quality as in comparison to their older Coby Digital CV-120, this headphone is really poor quality. CV-120 lasted for me for over 2 years and the sound from it was just fantastic; but this one sound stop coming from one side of the headphones. Really disappointed by this buy and too bad Coby has compromised their quality standard of their product, very sad.