I ran X 4 Mono Blocks for a few years with good results but it took a change in my Pre-Amp to do so; correctly (key word) and without compromises. I ended up buying a pre-amp that came with more than one pair of XLR outputs and was built from the beginning with the idea of being able to run such a configuration. In my case I purchased a Classe CP-800 which has output voltage (18v) to spare over all its possible configuration choices.
The other thing to think about is the matching/tolerances between multiple amps which were most likely made at different times and maybe even with slightly different parts despite being the same model.
If the Amp creator can say with confidence that his Amps all fall within a small fraction of each other in terms of their measured performance despite not coming from the same consecutive batch or run then you can feel pretty confident that the sound differences between them will most likely not be audible. I would say it would probably be best to group the amps together based on the time they were built. By this I mean, if you already own a pair of Mono Blocks now with consecutive serial numbers then place those on the R/L Mid/Tweeter channels or the R/L Bass Channels then when you get another set group those in the same fashion to limit any possible audible differences between the two batches.
When I was running this configuration I was using X 4 Hypex NC400 DIY amp modules that are known to be very close in their specs between each other and was powering a pair of B&W 803D2 towers which have two pair of binding posts per cabinet.
The other thing to think about is the matching/tolerances between multiple amps which were most likely made at different times and maybe even with slightly different parts despite being the same model.
If the Amp creator can say with confidence that his Amps all fall within a small fraction of each other in terms of their measured performance despite not coming from the same consecutive batch or run then you can feel pretty confident that the sound differences between them will most likely not be audible. I would say it would probably be best to group the amps together based on the time they were built. By this I mean, if you already own a pair of Mono Blocks now with consecutive serial numbers then place those on the R/L Mid/Tweeter channels or the R/L Bass Channels then when you get another set group those in the same fashion to limit any possible audible differences between the two batches.
When I was running this configuration I was using X 4 Hypex NC400 DIY amp modules that are known to be very close in their specs between each other and was powering a pair of B&W 803D2 towers which have two pair of binding posts per cabinet.