It's important to understand that the headphones themselves are by far the biggest factor here in whether or not the Realiser will live up to its potential.
I've come to understand that the physical comfort, imaging capabilities, dynamic capabilities, and a wide bandwidth are the most important qualities. Neutrality is also important so that the headphones don't impart too much of their own coloration to the emulation.
Talking to the people at Smyth, it was my impression that they choose to bundle the Stax headphones primarily due to their lightweight and comfort.
IMHO, the Realiser comes pretty close, but does not perfectly clone a speaker system. To my ears there's always an added high frequency emphasis (which, however, could be corrected for with eq) and the phantom center in stereo is not as solid and precise as speaker playback. Thus, a headphone that doesn't already have too much HF emphasis might be preferable to something like an HD800. Open headphones, which generally have more natural stereo presentation or ones that use angled drivers to create a better stereo impression also should be considered. Likewise it stands to reason that Harmon's eq curve that led to their "Room Feel" thing might do well as these headphones (NAD Viso HP50 and PSB m4u) are already tuned to sound like speakers in a nicely acoustically treated living room.
To answer your specific question, the headphones when used with the Realiser will no longer act like sonic microscopes and an amount of detail loss similar to when you listen to speakers should be expected.
For a general idea of what to expect, try Darin Fong's Out Of Your Head software to hear what I'm talking about.
Thanks for the reply.
The H-03 are extremely comfortable for me, lightweight, don't put my head in a vice, and don't make me "sweat like a pig". They are open back style electrostats.
Of course when it comes to imaging, dynamics, and bandwidth, everything affects everything, and if the speakers/cans don't have the capabilities much of what is done upstream won't have much of an effect..
I started assembling/visualizing this headphone system in my head based on my 40+ years of speaker based audio systems. Other than my PC server, some actively shielded interconnects, and assorted power cords I have the advantage of starting at ground zero.
Everything with the exception of my new DAC (should be here late today) has arrived a piece at a time allowing me to lock in on differences and improvements, or not.
By the way, pretty close will be close enough, once I get my big rig sampled. The added HF emphasis is not a problem for these old ears. They don't hear past 10kHz.
We will ultimate find out, but my big rig images so tightly that a little loss in the center precision will probably be adapted for very quickly by my acoustic interface/brain.
Before we moved and there was not longer a place for my big rig, I thought I had the speakers that would never be changed. Over a period of almost 9 years every change I made up stream was immediately audible. Speakers I brought in to replace them were never as revealing. So, I was set.
The H-03 and amp arrived first. So far every addition change has been immediately audible in a large way. Huge DIY power cords that were an integral part of my big rig destroyed the highs(that I can hear), detail, and delicacy that was apparent prior to their substitution. As each piece has been added the system has continued to improve. So I have had the advantage of hearing my cans sans the A8. I have had the A8 for two days now and even with just the factory sample I can tell I am on the right track.
I have a general question that I will put in the next post of this thread so it isn't lost in all this verbiage.
Again thank you for responding to my query.