I don't know about reference but some mono recordings played back on mono equiptment can have a very compelling presentation....not "better" than stereo or multi- channel but different and certainly not poor.But note I never said I couldn't enjoy the music and performance. I can and do enjoy poor recordings of amazing performances. But let's never confuse appreciation with quality of recordings. It's awesome when performance and recording quality come together, but nah doesn't happen often and no, I'll never ever declare a mono recording is in any way a reference...