Back in the 70's I started out hunting for high end audio (whatever that means). At that time high-end (to me at least) included McIntosh, JBL, and direct drive turntables. Along the way I happened into a music store that had a couple of home audio rooms where the sales staff works on salary and were free to offer whatever they wanted (as long as they generated comensarate profit/square foot).
I listened to the usual suspects, including JBL L-300 speakers (shaped like an undercounter refrigerators but 3 times the size) that retailed for about $6000 USD in today's money. They had a very good, typical hi-fi sound. Then the salesman said, "Now listen to this," and switched speakers. Instantly I could no longer tell where the sound was coming (they imaged so well) from within this typical retail setting with maybe a dozen pairs of speakers. I had to walk up to them to realize it was coming from a pair a small (12 inches x 8 inches x 6 inches) two ways. But the bass was amazing. Then the salesman pointed to the coffee table sized matching cabinet. This was the now semi-famous Irving M. Fried Model H with mass loaded transmission line stereo bass coffin.
I left not sure just what I'd heard, but the sound haunted me and I had to go back. Each time the sales staff fed me more of that sound and more knowledge, pointing out the advantages of accurate reproduction and imaging over hi-fi sound effects. A year later I bought the little 2-ways I heard and have owned Fried speakers ever since. My main speakers are still mass loaded transmission lines, but of Martin King derived design and built by Bob Brines, and are single driver based. The coherent natural sound, superior imaging, and incredible deep musical bass and the thrill it brings is still there.