What speaker could safely be ordered without hearing it first?

In my opinion Joseph Audio and Kef reference are safe bets, I ordered both without listening and they’re great

Having owned a Audiostore I would ask ,what is your other equipment, room size 

and $$ budget  all 3 things count in building system synergy 

for example if you have a Sonus Faber which is a bit warmer, or Wilson 

 all tubes would be too much of a good thing in warmth.,

that’s just a example , and also what type of front end Thst too can be tubey warm sound if you had say a Lampizator.

Avantgarde

I purchased my Theil 3.7s without hearing them first but had 2.4s prior so I was familiar with the sound.  Very happy with my decision.  Before I purchased the 2.4s I did some serious speaker shopping and listening however.  I was surprised at the differences between some of the reviews, what I expected to hear and some of what I heard.  Ideally, I would want to audition them in my listening room but there are a few brands that I would have confidence in like Wilson, Magico and Joseph Audio.  

That’s easy. A Martin Logan 👍