Ask yourself, “When is the last time I changed my guitar strings?”. If the answer is “I don’t know,” they need to be changed. I play Martin & Co. strings on my acoustic guitar. They sound full, crisp, and they don’t break easily, which is good for me considering how freaking often I break strings normally. Seriously though, order like 8 packs online and periodically switch them out for new ones. It really makes a difference.