Thank you all for a generous greeting.
My hearing is not what it used to be, but I'm told that's pretty normal for my age.
A saving grace is that it is very infrequent that I listen to anything at very high levels. You can get away with a lot more SPLs if it is not a regular recurring habit.
I'm sure many a people have wondered what the cyclic rumbling was, but since I don't subscribe to the local paper, I may never know if they're complaining about it.
I'll definately stop by the subwoofer forums. Looks like some interesting activity in Finland with all that testing going on. Here in the USA, it seems that many folks just don't care about sound quality, and there are videographers in this country who could care less that the bottom FIVE octaves of bass response are missing from their pro-grade video cameras.
My background is in Classical music, and I record symphony concerts, which keeps my ears 'calibrated' as to what a live orchestra sounds like. So anything reproduced that deviates in the slightest from that really irritates me to the point where I can't listen any longer. Being involved in the recording industry (I don't consider myself part of the industry--I consider myself a separate individual industry), I have the opportunity to stretch the envelope in the direction of removing barriers to accuracy and transparency. And believe it or not, subwoofers play an important role in accurate orchestral reproduction, because any coloration in the bass just sounds awful to anyone who hangs around double-bass players all night.
My contributions will be limited to mostly the scientific and theoretical, as most of the world of commercial consumer subwoofers and audio technology is in a different universe from the universe in which I live. That said, being a DIY'er for the past forty some odd years that I've found audio interesting enough to tinker with, I always enjoy a good DIY discussion.