Speakers that are good with tubes

I understand the value and intrinsic benefits of smaller tube per amps.  In my case, I opted for power and have a pair of McIntosh  MC3500 Mk2 power amps being driven by a McIntosh C2700. I am running Focal Scala Evos which sound great, but what are other speaker options?
 

You can have a 4 ohm nominal speaker sound just fine running the 8 ohm tap on a tube amp. 

@tubeguy76 With full knowledge that the tube amp will have to produce twice the power that it was designed for.  This is not a risk I would consider to be prudent.

Are you prepared to name the manufacturers who said it is safe?  How about running a 2 ohm speaker from an 8 ohm tap?  That may sound just fine, too, until smoke appears.

+1 Volti Razz - those things put a smile on my face every time

There is a Boutique company out there called Audio Note. I heard they make some pretty good speakers that perform well with Tube equipment. 

I’ve heard from amp builders and others how important transformer size and quality are for delivering speaker performance. No one’s mentioned it yet, and I am not finding a definitive source on the web, but these two are both decent.

https://www.psaudio.com/askpaulvideo/tube-amps-and-output-transformers/

and,
https://wallofsound.ca/audioreviews/amplification/what-difference-does-an-output-transformer-make/

My QS mono blocks have great transformers; they control the bass on my speakers extremely well, and I have compared them with some very good solid state.

What this discussion seems to indicate, then, is that there are a number of commensurately important factors necessary to creating good sound. Finding "synergy" between speakers and amps is not magic; it comes down to understanding the various factors on amplifier and speaker sides, and matching them. Then, listening.