I use to have a pair that had the volume controls built in to them, they broke, so I went to Curciut City and put down $30 on a set of Kenwood kpm-510 personal monitor head phones, they are full size and fit over the ears, I love them they don't have built in volume controls, but if you detector don't have volume controls then you would have to find a pair with volume controls, plus the pair I have came with a small head phone plug, I needed to get an adapter so it would work with an RCA jack
Rob, There is Hobbyland in Mishawaka, they are a whites metal detector stocking dealer Store Phone Number 1-574-255-1722 thats all I can find!!! usually its a different type of shop that sells detectors, like my detector came from a coin shop, it might be tough locating a detector dealer! How about puting your own thread askin about any shops in or near South Bend!