My friend Ernest was in charge of the software development for the BAP1000. I had my ears measured at AKG back then. They put you on a swivel chair with tiny microphones in your ear, measuring the characteristics of the ear with regards to orientation. The offered that service to musicians. So some AKG guy got sent measuring with his measuring kit around the world. So this obviously only makes sense if you sell the set. The Scorpions (German Rock Band known for "Wind of Change") had a set. They used it as "portable Studio" when they were on tour...
I spent practically whole day yesterday with BAP-1000. First, in the morning, to select as diverse as possible binaural DSD recordings of my own from the hard disk to Korg MR-1000 DSD recorder, then listening to these on the BAP1000/K1000 at friend's, who had to decide whether or not to purchase the combo - and I brought another K-1000 , owned by my friend who produces most of my recordings and were modified by me, for reference I know really well.
At first, from the cold start, BAP1000 sounded - horrible. Thin, grey, grainy - everything one does not want. A quick comparison with iFi Audio iDSD micro left no doubt as to which one is better amplifier , used in straight mode, without any alterations to the input signal. It was iFi micro that clearly had the upper hand.
Then friend and me concentrated on listening to the headphones themselves. If someone still thinks bass heavy and bass light AKG K-1000s are a myth, I can attest it is NOT so. "To be bought or not to be bought" candidate was decidedly thin and without response in the lower octaves - compared to a bass heavy sample that was further modified in order to bring the best out of this design.
This swapping of headphones and direct comparison of both amps went on for about half an hour - and we always swapped so that whatever the headphones listened to, we were always listening to the same combination of ( AMP+headphone). As it got tiresome ( and wire tangling...) experience, at one point we simply swapped the headphones - and the amps driving them. And, although not surprisingly to me, the at first horrible sounding BAP-1000 did put itself together to something listenable - the difference was obviously becoming less and less.
And that finally allowed for the functions of the processor to be tried. And, yes, as good as K-1000 is in soundstage department, it can be significantly improved by the judicious use of BAP-1000. I can atest to that, as all the music being listened has been recorded by myself and know how it should sound. The best feature that the music no longer plays "in the head" or is "stretched from left to right, way beyond the width of the head" - to something that very much resembles music heard live - on the stage in front of you. With my binaural or Jecklin disk recordings, the "filter" that produced the best response was number 8. I know there is option "Card" - for individual calibration - but that was understandably not available yesterday. If I owned BAP-1000, I would definitely have my ears measured - period.
All you wrote above holds true. Specially that "portable studio" bit. All that is needed is a QUIET room. Luxury that is usually not available when doing recording on location - which in practice means driving the musicians out, so that conductor/player/singer/producer can listen during microphone setup - which is not particularly gentle on the musicians, if that means driving them out to the snow, in an already cold church - for example. But people just can not seat in total silence for some 10-15 minutes until conductor/musician/singer/producer can listen to agree on the best microphone setup - K-1000 blocks absolutely no outside noise and even the quietest of whisper can tip the balance in favour of an otherwise inferiour mic setup.
During this write-up, the happy new owner of BAP/K-1000 called me on the phone - raving how much better it got still after yet another of some 5 or so hours of being powered up. I will occasionally chime in how things will progress from now on.