As you might infer from my username, I'm probably in the older half (Ha!) of this group. My oldest son has been an audiophile for years. He's been doing car audio projects for himself and his friends for years. Last year or so I persuaded him to assist me in building a portable 2.0 system for small meeting and classrooms. Mission creep set in. I ended up with a 2.0 system, but I also now have a 2.1 system which gets 99% of its use as my Mac sound system. My son designed a bass reflex system with a 6.5" woofer that is tuned to 45Hz. It will reproduce 30Hz if the YouTube video I was using is correct, but he told me not to crank it up below the tuned frequency. Anyhow, it's a great system and I'm enjoying hearing all the parts of my early boomer tunes that I've never heard before. We are now rebuilding a pair of 41" high Kenwood "dual port" enclosures from the late '80's. The woofers are still good and will be reused.