Not necessarily. Having a detachable audio cable depends on the model and the manufacturer. While some models have the facility, some don't. It is always recommended though to go for a headphone that has an audio cable port, so you can have uninterrupted streaming in case your Bluetooth connection doesn’t work for some reason. Having a detachable audio cable also makes the headphone more versatile allowing them for wider applications in studio functions, unlimited gaming hours, etc. Read our 'Bluetooth Headphones Buying Guide' for a better understanding of your query.