What going fully Class D has taught me.

@erik_squires --

Focusing on the difference in amp to speaker interfacing through the passive/active configuration and the effect it has/what it facilitates sound-wise (which also, to some extend, comes down to the Hypex DSP section in the active scenario) it’s important to have in mind that, presumably, you’ve only heard either amp - the Luxman and the Hypex solution - in each their particular configuration, passive in one and active in the other, and this is not trivial - certainly insofar what you’re pursuing here is a more isolated assessment on the different amp designs/topologies, or active vs. passive more fundamentally for that matter.  

An active setup isn’t confined to plate amps of a certain design nor a DSP that’s tied to it; try imagining using 2 of your Luxman stereo amps to run your 2-way speakers actively with a 2 ch. input/6 ch. output external DSP, and then setting up your sub towers actively with Hypex plate amps and using the same external DSP. Yes, it would be more expensive with the need for yet a Luxman amp + an external DSP, but for the sake of the experiment ignore that for a moment and consider the following: you would "get to know" your Luxman amps in a different context, one that would free them up and which, I’d argue, could make you have your cake and eat it too.  

As it is though you’ve placed yourself in a bit of a quandary: a particular active scenario has you yearning for certain traits of the passive one, and vice versa. Coming down to it class D technology more broadly has something to offer that would border on the Luxman, and conversely the Luxman is only one tasting of class A/B. Not to mention what the interference of a passive crossover between a given amp and speakers, or its negation, does to the sound - both of that generated by the amp and that coming from the speakers.

Bridging the divide here and getting more or less the best of both worlds is certainly possible. To me active is the only route, and once you make that decision and refuse to let yourself be limited by a particular amp design, a bundled solution or other, there’s really no reason why you won’t find yourself outside of named quandary - not least in light of your entrepreneurial spirit and technical insights. 

Maybe I’m just lucky, but the 2 class D amps I bought to use in my space constrained home office both sound very good on a succession of speakers (good 2-ways including Harbeth 30.1s, ATC SCM12 Pro, and KEF 103.2):

• Wyred 4 Sound ST-500 (ICEPower): sounds great at all volumes, not sterile, cold or edgy in the least. It puts out so little heat that (w/W4S’s approval) I stand it on its side IMS)
• bel canto 600M mono amps (NCore): also sound great all volumes, also not sterile, cold or edgy. The sound is a bit more resolved and elevated than the W4S, but these are very small differences

I no longer have big speakers in big rooms. My office system is a pretty high level nearfield setup. So I can’t claim that either of these class D amps would equal tube amps or good A/B amps in terms of soundstaging and timbral accuracy in typical (not nearfield) system setups. But IMS and for my needs, both amps are ideal.

FWIW, I am now and always have been very sensitive to edgy, tense-sounding SS components (have owned a number of amps/preamps/DACs like that). These class Ds are not in that camp at all. 

For very revealing two channel, D still leaves something to be desired. It's definitely the only way to go for home theater and multi channel. BTW, ICE has fallen way behind. For the best bang for buck look to Purifi Eigentakt or Hypex NCX500 modules. 

I don't know about ICE falling behind, but to my ears it has a warmer sound.  Closer to Parasound Halo amps than my Luxman for instance.  I don't need it to be better IMHO, it's just got its own signature, much like linear amps. 

@phusis  - I specifically made the sacrifice to minimize the cables I'd need otherwise, especially when trying to integrate HT and 2-channel sound.  Last thing I need is multiple amps, external DSP and more cables. 

I've realized recently my Hypex plate amps have 2 RCA inputs.  This makes it possible to run a separate source chain (DAC/preamp) directly without the usual HT bypass features.