The best speaker you ever heard?

Unquestionably Radio Shack Mark 1. That big woofer and horn just pump out the tunes. A sought after classic.

You're Kidding me Man! Oh yeah, you are Kidd "ing-Me" Man. Nice fishing.

I worked at Radio Shack for 5 years or so back in its hifi heyday. Those were my least favorite popular RS speakers. Tried to talk people out of buying them, except maybe when a good sale ran. They always sounded like all the bad stereotype things you hear about horn speakers, boomy bass, shouty and shrill. Maybe with the right tube amp that RS no longer sold. That was the heyday of the SS receiver/amp, mostly made in Japan.

There's something worth paying attention to, as we talk about "best" as relates to speakers there's a big difference between those costing over $50k, under $10k, and somewhere between.

Yet there are those notable speakers that don't break the bank and we find guys having tens of thousands in components due to the fact that the speakers fully reward the extreme gear.

Look at the level of cable that seems "right" for an $80k set of speakers, we think nothing of that audiophile spending ten or twenty grand on speaker wire and the interconnects are no price bargain either. Yet the same system and wire can be put to any level of speakers and you will never hear them sound better, you will never hear more audiophile qualities out of them.

Big guns audiophile sound can be had with some of the sleeper speakers out there like Magnepans, and there is an array of components that perform way beyond their price point, same for wire.

I used to put a giant killer system together for less than the cost of a set of the monster speakers typically associated with six figure systems. Even my best value wires that cost a fraction of what they outperformed still put the wire at over the cost of the components. Heck, I was using $3500 power cords on $4000 monoblocks. But here's logic for you that's inescapable, if you are going to put a $4000 amp up against a $30k amp and that amp sounds better with a $3500 power cord the $4000 amp has to get the same power cord and wire to be fairly compared. So what if the power cord costs as much as the amp, where does your logic sit on which you'd rather have, the $30k amp and $3500 power cord or the amp and power cord as a combo that soundly out performs the more expensive combo? For some people it's more about how much it cost, for others it's about what it sounds like. Audio gear doesn't lie, and the only way stellar sounding speakers can compete with those costing vastly more is to be on an equal system footing. So we find ourselves working systems up from speakers that have huge performance reserves, and there are a lot of them out there.

The best speakers I ever heard were on the best systems I ever heard.

BP7000sc OK,OK I have not heard any speakers over $16,000, but I have heard most of the more available speakers under that number. I owned Linaeum Model 3s for years (Sad story about that company and technology). I tried Def Tech Mythos when I thought I was going into "Home Theater". The theater idea was a joke but I discovered that I did like the Mythos as standalones for music. Moved them into the listening room and liked them very much. Broke an input and called Definitive for a replacement. Had a great discussion and asked them what was the best speaker they had ever made. "The BP7000sc" they said. We talked some more and it turns out they still made that model even though they don't advertise it much. Long story short (too late for that, I see), I bought a pair. WOW! I have a large-ish room (5400 cu. ft.) and these guys fill it up.
I like the bi-polar approach. And get this - because of the built in 1500w bass amps, they are so efficient (92db I think) that they can be played with 8 watt tube amps! The midrange is superb - great layering and depth. Spot-on timbre. Treble is goes way up, no sibilants. Unforgiving on bad CDs. Bass is prodigious yet tuneful when dialed in.
Only weakness I hear in this speaker is that the bass and the rest is not quite as seamless as it could be on some material. Still working on this. Seriously, open your minds and give a listen.