@kraftwerkturbo wrote:
"the next speaker design I want to try is a still small speaker but with two low/midrange drivers simply to be able to play at ’concert level’ without distortion; but still no need for very low bass.
"Since still in the trial and error and validation phase of my ’concept’, any small 2 (if needed 3) way candidate must also fit the VERY low price (used) criteria ($1,000 or less)."
I have been designing speakers specifically for use with subwoofers for close to two decades. As you mentioned, this frees up the main speakers from needing to handle the low bass, so they can be optimized for the rest of the spectrum. But the main reason I embrace this approach is that imo there are subwoofer solutions whose in-room performance is significantly better than equivalent-on-paper main speakers in the bottom two octaves.
Unfortunately I have no recommendations on how to achieve "concert level without distortion" above the subwoofer range for less $1000; explore the used speaker offerings on this site and hopefully something will stand out to you. You might especially look at companies that have a prosound heritage. JBL and Klipsch come to mind; include Zu because they use prosound-type drivers. Also look at Tekton; I don't think their Mini Lore is realistically capable of "concert level without distortion", but it probably comes closer than most in its price ballpark.
Very best of luck in your quest!
Duke