I know it exists because I've heard it and read about it a lot but I don't understand it. The only time I heard it was way back in highschool physics class! Maybe I'm hearing it all the time and it just sounds "normal". Bear with me in my musings of what is going on with phasing.... My understanding of porting is the "free lunch" is a boost of the low end with a phasing cut of sub freq so low they don't matter and a similar cut in mids which together we hear as "good". The amount and position of that bump/cut is a big chunk of the "voice" of a cabinet. My own 2x10 SWR JrIII and Trace Elliot 15 rig sounds fine to me. My ears aren't the greatest but it sounded fine to a recording engineer fella at a gig when I asked him so I can only assume there is no phasing in that combo. I'm thinking if mismatched cabs generally sound ok it must be that most cabs are tuned for same enough frequency bump and it's the amount of bump and the different drivers EQ response that make them sound so different individually?