What exactly is a speaker box sound?

@richopp 

Magneplanars, as good as they are, have their own "sound" too. I recall oversized instruments and voices as a result of the large radiating surface. We each choose the distortions that we find easiest to live with.

@roxy54 

Exactly why I suggested to the OP that he listen to EVERYTHING and buy what HE likes.  While we may disagree on what Maggies "add" or "sound like" in a given situation, I, PERSONALLY, have never heard a more accurate reproduction of the source material when the ROOM is right and the HW is top-quality (ARC in my case).

My shop sold over 20 brands of speakers, so I definitely understand that people have different tastes.  My point to the OP was to listen to as many DIFFERENT things as possible before making a buying decision.

Cheers!

Exactly why I suggested to the OP that he listen to EVERYTHING and buy what HE likes.

It's a little sad people think you only come to audiogon when buying.  This thread is for discussion, and curiosity for me, not to help me buy anything.  I always buy what I prefer to listen to, if I can't make it myself. :)

My point to ask this question is in part that I haven't heard actually terrible speakers that sound like boxes in a very long time.  Was wondering what is out there today that has this quality.

It’s a  thing of the past for anyone who cares. I wouldn’t give it a second thought.  Still a thing with cheap mass marketed speakers that anyone with ears and even a little money can easily avoid if it bothers them. 

You should try some computer speakers and small pocketable bluetooth speakers. You'll get that "tiny driver screaming in a tin box" effect.