Which pair of speakers changed your Hifi life?

While I didn't own the following speakers mentioned, they had a lasting impact on me:

Yamaha FX-3. Heard them at a local dealer in 1980 with my brother and father playing the then recently released Pink Floyd double LP 'The Wall' - "Another Brick In The Wall, Part II." I was 8 years old, and at the time already being very interested in sound reproduction they blew my mind. 

Some 4-5 years later, Snell AII's. My first acquaintance with a stage, coherency and timbre of this kind. Lovely speakers. The later AIIIi's were less convincing to my ears. 

Around '90/'91 I heard a pair of JBL K2 S9500, and was astounded by their explosive dynamics and clean, visceral presentation. I was already quite familiar with the sound of larger JBL models like 250Ti, 4430, 4435 and Everest DD55000, but this was something altogether different. To date the most dynamic JBL domestic line speaker I've heard (incl. the Everest DD67000), no doubt aided by the crazy powerful 1400ND (first neodymium magnet) woofers, Bessel tuned. 

S.P. Technology Revelation + dual EV TL880D subs, some 10 years ago. The interesting takeaway auditioning this speaker setup was that I heard the transformation from their original passive configuration to a fully active ditto, which convinced me of the natural attributes of going active and that it was even possible this way

That effectively settled my audio path going forward some years later pursuing active configuration myself, though "married" with a different approach in speakers more in line with and inspired by the K2 S9500's mentioned earlier, which is to say large, dual pro style woofer/mids and compression driver/even large horn as a 2-way main speaker setup, augmented with a pair of tapped horn subs. 

In my 58 years, I have owned about 20 pairs of speakers. The only ones that were purchased brand new were the Sony SS-CS5 bookshelf and the tower version the SS-CS3. So yeah, nothing to write home about budget speakers. Good for the price and for what they are. As far as used ones, they have all been of a wide variety but always floor standers. A couple years ago I scored an almost mint pair of ESS AMT 1B’s at an estate sale for $60.00. All they needed was a refoam on the woofers and new passive radiators. That Heil tweeter was outstanding. I sold them locally for $700.00. Not long after that, I bought a new pair of Tekton Enzo XL’s. I simply loved them. If I could go back in time I would have bought the Double Impact or even Moab and likely would have been done playing speaker buying and guessing games.       BUT WAIT! While walking through my local Salvation Army store, I eyed a unique looking pair of high gloss black speakers in the furniture department. I Googled them and nothing really came up on them (to the best of my recollection). I had never heard of the brand before, but just judging by the cabinet finish and the typical "knuckle wrap" test, I immediately suspected that I stumbled on a really decent, older pair of large speakers. They both had a price tag on them. $250.00 each. I asked the cashier if they were really $250.00 each and not for the pair because nobody is going to just buy one. Nope, they were $500.00 for the pair. I walked around the store for a bit weighing in on the WAF and decided that I was going to do it. That’s a lot of money for a Salvation Army item, but darn it, they had such a nice finish and a serious looking 12 inch woofer. Well to my ears, these speakers ended up sounding every bit as good as the Enzo’s and were a quarter of the cost. I still have them after 3 or so years and I will never sell them. They are Amrita Audio Reference Standard speakers. It turns out that they have a 13 inch woofer with cast aluminum frames, dual 6.5 inch Dynaudio midranges in their own sealed enclosure within the box, and Vifa aluminum dome tweeters. I believe the efficiency is 92db and they are 6ohm. The gorgeous gloss black MDF cabinets are about 49 inches tall, 14 inches wide and 16 inches deep (all approximate). I believe they were manufactured in 1992 and sold for $3500.00. For the pair, not each LOL. I’m not sure what they weigh, but they are stout for sure. The bass is certainly adequate and the midrange is very detailed and forward. Pretty cool that these were not produced in very high volumes. I still don’t see any for sale anywhere and I look fairly often. I would love to be able to A/B compare them to the Double Impact speakers. My inquiring mind is really curious if they are close in sound signature.

My fathers Quad 57's which got me into audio in the first place

Proac EBS studios - purchased in 1982 - which had ATC midrange drivers. Just sold them last year to get current ATC gear.

Audio Physic Special addition Avanti 5 . Predecessor of the Avantera.

Snell 2c mk2 with Adcom electronics Woo really missed them when I switched to canton 9K monitors and Technics Integrated sug 700, that is until I added a SVS SB1000 pro sub. Forgetaboutit this system crushes the Snells in all respects.

I might also add the tech support at SVS is freaking outstanding! Technics support on the other hand absolutely sucks. No sucks is too kind it is nonexistent! Seriously stay away from that company if anything goes wrong with their product you are alone, buyer beware. They do not have working phone numbers, texts and emails go unanswered. Panasonic the parent company is up to something. Lucky the amp works fine but man what a crap company avoids them like COVID 19, no make that Ebola.