Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Junky XM Sportscaster Headphones

When it works, this is a nice low-end portable XM unit. The major drawback is the heaphones. The cable that plugs into the Sportscaster receiver is not very sturdy. Eventually the wires inside the cable break, and the headphones won't work anymore. The Sportscaster will just display "Check Antenna". Since the headphones have the XM antenna inside, you can't just replace them with somethng else.When my first set of these headphones stopped working, the company replaced them under warranty. Now that the second set has stopped working, I gave up and purchased a different XM receiver rather than invest any more money in this poorly designed product.