What creates the effortlessness in sound reproduction?

grannyring,  I agree with you that some companies/drivers are much better at attaining an effortless sound than others. Dali makes an excellent product, and I have thought of reviewing one several times. 

I am spoiled by regular use of larger speakers, which has skewed my expectation, standard of what constitutes refined sound. I would struggle to accept a monitor or smallish floor standing speaker as my reference. If the bulk of my experience was with speakers with 6-7" bass driver(s) likely I would agree with you entirely.

 I struggle to think of any driver under 8" across the industry that has an effortless sound when listening at higher levels compared to much larger drivers. Others disagree, so be it. The perceptions and expectations of audiophiles in terms of sound are as wide as the performance of systems themselves. I'm not expecting anyone who has not used much larger systems in their home to agree with me.  They may work hard to get a smallish speaker to sound far more relaxed and effortless relatively compared to their earlier systems, so they think it's got a high degree of that attribute. In my experience not so in comparison with far more formidable speakers. 

The smallest dynamic driver I have heard in my room that can put out 20Hz +/- 3dB and not sound strained is the Audio Technology 11" in the Vapor Audio Joule White speakers  (reviewed for Dagogo.com)  YMMV

All good points Doug. Many of us don't listen above 75-89db average weighted C when off the leach!

Effortless sound comes with a proper amplifier match to a given set of speakers.  
Obviously HE speakers need the least amount of quality power to deliver fast, responsive effortless sound without strain.  
Yet typical low efficiency dynamic box speakers can also sound effortless with the right amplifier.  
My 86db large british monitors sounded exceptionally dynamc and effortless being driven by a high current Bipolar transistor amplifier with 300 WPC.  The results were literally startling.  

I think a system's perceived effortlessness can be achieved by a judicious application of effort.

@douglas_schroeder --

Peter is above board. The shameless ones are those with ulterior agendas.

Even without hearing the speakers he linked to I can see that they have many of the criteria necessary to achieve effortless sound reproduction - given the proper electronics and cables ahead of them.

Larger drivers, extended frequency response, plenteous power, overbuilt x-over or active x-over, larger speakers well past 4’, etc. Many speakers have a few of these traits, but this one he linked to seems to have the necessary attributes to create the effortless sound discussed here.

I have reviewed larger Legacy Audio speakers for Dagogo.com, such as the V and the Valor, and these are fundamentally superior in creating the sense of ease and capability beyond the norm. So, Peter’s link is not just shameless promotion, it’s a snapshot of the characteristics in a speaker that lend themselves to "effortlessness".

Btw, it seems the speaker uses a 12" mid. Those with discernment might look to see that also Legacy’s Valor similarly uses prodigious midrange. Why is that? Because it is fundamentally superior. Period. End of discussion. Size matters, and big gets fundamentally better sound in the end. Sorry for budget audiophiles, but that’s the realty.

Now you know. :)

Indeed the size of speakers/transducers matter, but sadly large size and high sensitivity is often dismissed, no doubt partly due to size costing obscenely much these days with refinement being taken to ridiculous lengths and putting the price of small standmounts into 10’s of kilo-dollars (imagine where that leaves their grander brethren on the price scale).

And yet, where price is no issue it seems a fortune is generally rather invested in moderately sized speakers instead of letting physics have their say; sometimes it even appears as if physics to audiophiles, certainly in regards to speakers, is tangential to the importance of belief for an atheist.

Interestingly, but to no surprise John Atkinson of Stereophile "wriggles" his way around the question of large speakers as well:

https://youtu.be/QWU2sUnW-eM?t=1344

It’s worth mentioning that size (i.e.: air radiation area) is achievable via other means, namely from acoustic transformation as well - also known as horns. To boot this is the most effective way into high efficiency, you’ll have similar or more impact with less cone area (with all that entails in regards to inertia), and the coupling to the air is more effective in ways not only translatable into higher sensitivity. Of course, when we enter the region of bass the laws of physics dictate very large to monstrous size horns, depending on the specific tune and how low one needs to go.

Headroom is certainly paramount where effortlessness goes, and to my mind powerful amps are in vain if the speakers aren’t properly efficient to convert that power into actual SPL without strain and thermal compression (save active iterations like larger ATC’s). Realistic dynamics requires more than one would think. There’s also SET’s and how they provide that elusive flow/liquidity and ease to the sound (which, for full effect, requires high efficiency speakers - in effect mostly horns). Class A amps in general, incl. SS designs, appears to have that ability to some degree as well.

Thinking about it certain speakers are inherently ’easier’ to listen to than others, and this may be related to timing aspects in particular; music somehow presents itself more simply, relatable and genuinely via some speakers, as if the brain is working less overtime trying to stich together the sonics into a coherent whole. Listening to Synergy horns be Danley Sound Labs only confirms this..