Best small, desktop speakers, $500 or under (new or used)

If you can find a set of Radio Shack Minimus 7s, they work great for this sort of thing. There are some nice mods you can do them to wake them up. The early ones are apparently the ones to look out for. If sunbleached the woofer will be white instead of black.

Infinity Infinitesimals. The first two versions.. Aluminum/Mag cast speaker with hardwood cap and pedestal. 200-1000.00 Great resale, They have it all for a small bookshelf or desktop.. They play down to 60 or so. and with true ribbons, you’ll get your mids and highs, with a bonus of good bass. Nice speaking point too. True Reference Standard speakers of that era, and this one too for that matter.

One thing they have DVC Watsons. I've never had a bad one, BUT that is a part that can be hard to come by,
everything else, there are parts for NOS or used..  There are kits and repair services for the Watsons, still,
and will be for a while..Be aware though.. I have two pairs.. Wonderful speakers..

Regards

Great suggestions. Thank you both!
"Radio Shack = Realistic" I think. If not, please correct.

Is size of concern?  Where will you place them?  Whats your source going to be?