Speakers The single most critical component


I know we've been over this Q hundreds of X's over the past 20 years here on audion, You can find dozen of topics dealing with this Q <which is the ,,,,most important component...>>
well time for yet 1 more topic dealing with this,, perhaps unanswered, un-resolved issue.
I'm bringing up the old hachet due to my recent experience acutally hearinga FR in my system. 
Let me tell you, there is not even 1 traditional/conventioanl/xover design <The Boxed Type>> in the world that could convince me  , there is something that will beat out FR (caveat, FR requires  some sort of high sens =sensitivity, tweeter)  in  the Boxy world of speakers.
That is to say, FR + Compression Horn is the future of 21st Century high fidelity. 
One lab has already brought us these ~~~SHF~~~ aka SuperHighFidelity  single drivers. 
The code word here is ~~SHF~~~ which can not never be employed when describing xover/trad/conventioanl style  aka The Box designs. db level under 91 are _<<IN-EFFICIENT>> , = dysfunctional, out dated, old school , = Dinasaurs. 
For amps, I only consider tube amps (PP and SET) as ~~SHF~~~ I can not include ss amps in this topic. 
IMHO all well made tube amps sound very close,
 a  kt88 in brand X will sound  close to brand Y. 
So amplification takes a  distant 2nd place in critical component.  No need to break the bank buying amp A vs  a  lower priced kt88 amp B
CD players, nearly all  tube DAC's , tube cdp-ers sound  close. No need to braek the bank over X vs Y.
My Jadis DAC is  only miniscule gain over the Shanling,
 the Shanling
only a  miniscule gain over the Cayin CD17. 
Now as for  best source  , phonograph is the ideal playback medium vs cds. 
I have some LP's now , but my main collection are classical cds, most not on LP version. Cables , I did note some gains employing silver/copper wiring throughout my entire system including inside the Defy.
Tweak worthy.
New Mundorf caps in all componets, tweak worthy. 
Yet the main central component remaisn the speakers.
Here is where  the entire audio resolution either rises to Nirvana or falls to <<distortion/muddy waters,/pollution/anti-fidelity  voicing  issues.
Your system's fidelity is ultimately dependent on what speaker  you have chosen to employ.
Forget all you've learned over the years, 
The new mantra is <,The speaker is key component>
All else is just extra tweaks/nuances. 
To sum up, a  ~~SHF~~ driver will match even the top of line Wilson weighing in at hundreds of lbs priced $$$$$$$ overa single FR driver. 
FR beats out any/all xover box design speakers. Mostly due to that key specification ~~db level~~~ which is everything in speaker design and thus in resolution/fidelity. 

mozartfan
I've heard many different speaker types, and many different systems employing ful-lrange drivers, many of which I really liked, but, I would hardly say that such drivers beat out all others.  I've heard many single driver fullrange systems, as well as full-range drivers used as a wide-range driver in multi-way systems.  The full-range drivers ranged from cheap, but quite good Tangband drivers to field-coil drivers that cost about $30k for a pair.  The best commercial single driver system I've heard is the Charney Companion with the AER driver, followed by a Voxativ system and then the Cube Nenuphar.  I have heard, and liked systems with full-range drivers plus woofers and full-range driver plus tweeter, and full-range driver used as a wide-range midrange in three way systems.  My favorite multi-way system with a full-range driver is an open baffle system employing a Jensen M-10 full-range driver and a Jensen RP 302 tweeter (custom-made system).  An example of a good commercial full-range driver plus tweeter speaker is the Soundkaos Wave 42.  Similar to the full-range plus tweeter system are two way single-driver coaxial systems such as those built by Tannoy and Trenner and Friedl.  

Of course there are many other kinds of drivers in many other kinds of systems that can deliver great sound, including many others that avoid complex crossovers, such as full-range electrostatic speakers.  I don't think any particular kind of speaker corners the market on great sound.

While it might well be the case that speakers matter the most when it comes to determining the basic character of a system, it is hardly the case that "all well made tube amps sound very close."  There is an incredibly wide range of differing sound characteristics among well regarded amps.  I heard a comparison of two very fine amps where a relatively modest pair of speakers was employed to show how differences between amps matter.  
Nope .... I disagree. Intuitively, speakers matter , BUT, and its a BIG “BUT” ..... the speakers are no more important than the rest of your system components.

In brief: Let’s talk about your upstream electronics. There is a well-travelled and time-honoured homily in this crazy hobby:
” ... Garbage in = garbage out!...” (full stop).

Your post sounds like machine code for a tweeter and a midrange driver.

Of course, speakers are important.