I read the quote by EG with some amusement. For the following reasons:
- Least critical to whom? Just because they cover about two octaves does not make them less important just because he says so. This is very much a personal judgement call. I suspect the quote is out of context, and he was talking about driver design, in which case it would make more sense to me.
- Those last two octaves are the hardest to get right consistently by the average consumer or even audiophile. Meaning, sometimes you luck out and a lot of times you don’t and need to put a lot of time and effort into it. Most audiophiles who care about bass have had to go through a number of experiments before they were happy.