Your budget is flexible you say? System audio makes some really great book shelf speakers, pair these with a echo link and your good to go. https://system-audio.com/product/sa-legend-5-silverback/ https://www.amazon.com/dp/B0798DVZCY/ref=cm_sw_r_cp_api_i_HVAZWRJW263HP0TQE8VV

If you have any Amazon Echo devices, you can pair it with Echo Link then connect it to your Denon.

If you just want Bluetooth and something cheap, this bluetooth receiver should do it