Recently while messing around testing some other gear, I was running some 20, 32 and 40Hz sine wave tones through my L112. Driven by Carver M-4.0t (380WPC). I kept noting an odd distortion-like sound and finally realized it was the ports. I could actually feel the wind blowing out of those ports, and putting my hand over the port stopped the sound. It would vanish at 40Hz but get progressively worse below 40. Even at fairly low amp levels it was plainly audible.
So, I've finally discovered what "port chuffing" is. Obviously it would occur pretty rarely in normal music listening, but it prompted me to wonder what might be done about it. Don't later speakers use flared ports to prevent this? Is there some port mod or replacement that might fix this?