Thanks for asking, Craig and hopefully providing some advice.

In my main room, my sources are a PS3, Amazon Firestick, a Google Chrome and a Yammie cassette deck. All that connects through my Onk which supports 192KHz/24-bit formats. The majority of my listening is via Spotify Premium via the Firestick. The Onk has Spotify Connect but I've never been able to make it work. BTW, I notice Spotify via the Firestick is better sounding than via Chrome and PS3.

I don't have an external DAC. I've never used one and frankly don't know what I don't know. Total noob.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated