The microphone jack lets you use these speakers as karaoke machines or loudspeakers.
Brad's Deals Editor David,
The Ion Audio Arena Bluetooth Speaker System drops from $79.99 to $64.99 with free shipping at B&H Photo. This is the lowest price found by $15. These speakers have a microphone jack for karaoke and a standard audio jack for connecting devices that don't have Bluetooth. They also have a USB port for charging other devices. Sales tax is charged in most states.