What is a good all around high quality speaker to purchase?

@onehorsepony 3.7 is one of Thiel's best if not the best speaker created.  Thiel owners would not be happy with those kind of words. B&W Nautilus or Diamond are musical with tight bass.  Not sure what speaker you need along with yiour equipment.

I ran Vandersteen Treo CT's and Quatro CVT's with that same set of electronics and they both were a great match for the PS Audio gear.

I have many speakers and set ups... and... those that stand out as being the best for the money are the following:

1.  Linkwitz Orions or LX521s - the most life-like speakers I’ve heard!

2.  Harbeth 30.1s / 30.2s or 40.2s - with the right set up they sound very much like Quad ESL-57’s - the best there is!

3.  Maggie LRS+ - with the right set up - as life-like as you’ll ever hear at a bargain price! They are truly remarkable!

4.  Anything Legacy - expecially the XD versions - as good as you will ever hear - very few speakers can match their sound - most don’t! 

Now - you’ll notice that 3 of these are dipole / open-baffle designs - which makes a huge difference!  Nothing quite matches dipole / open-baffle designs - the most life-like speakers you will ever experience! Their sound-stage and imaging are unmatched!

While the Harbeths are not - they still produce a sound that is very similar to dipole speakers (a la the ESL-57s) and have a very rich, yet transparent, high resolution sound.  

All of these are unmatched for "all things acoustic" (jazz, classical, country, bluegrass, blues, etc...) - if - you’re into anything else you might as well buy anything, because you won’t need the subtleties of dipole / open-baffle speakers.

Also - if you have an over-damped room (carpets, drapes, etc, etc.) you might as well buy anything, because you won’t need the subtleties of dipole / open baffle speakers. 

And as usual - you must mate any of these with well matched set ups - or- you'll never achieve their true sound qualities! But... if you do... you will be amazed!

A great way to evaluate these is by their YouTube Demos - just listen to as many of their demos as you can find.  It will become very apparent to you how much better these sound than all others - IF - you are seeking "all things acoustic" sound.  Nothing compares! Don’t believe the BS that you can’t hear their sound qualities via tiny speakers via YouTube - you can very much so!

Again... IF.., you listen to "all things acoustic" you will love any of these speakers!  

onehorsepony

$20,000 is a great budget for sure, so here are some excellent all around speakers that work really well in most environments and are not too finicky. Some are open baffle, some are flat panels, some are horns, some traditional box speakers.....but all are brilliant.

Joseph Audio Perspective Graphene $20,000, Pure Audio Project Treo 15 $8,800 or Quintet 15 $12,800 (I prefer the horn version, but there are several options for tweeter/mids), Volti Rivals $16,900, Yamaha NS5000 $15,000, Fyne Audio F703SP $19,000, Revel Salon 2 Ultima $15,000, Sonus Faber Serafino G2 $22,000 on sale or Olympica Nova V $18,000, Diptyque DP140 $18,00 (If you like flat panels), and Linkwitz 521-LX Reference $18,000 with US shipping.

Best of luck to you, and let us know what you do