Banjo Boom

With a Banjo or any spring instrument of your choice, you create two giant arcane boomboxes that appear either side of you. You create a line with a 30ft range with a width of 10ft. Anyone within this area has to make a dexterity saving throw (Using your spell save DC), upon failure they target is pushed back 10ft and they take 8d6 thunder damage. Upon success, the target stays puts and takes half 8d6 thunder damage.