Woofers getting workout, but no bass

Yes, ported speakers are more commonly susceptible to this kind of thing from what I have observed over the years, but I think the problem can affect other designs using dynamic drivers as well.

I think since porting is a very common approach to extend low end response on speakers that the problem is more common there, but not a result of the porting itself.

Not sure about IMD distortion, but it still might result in faster amp clipping even with a planar or electrostatic speaker with similar frequency response I would think.

Are you saying a ceedee playing down to,say, 25Hz will also cause excessive excursion? I think that ported speakers may be more susceptible, but that doesn't tell the hole story, IMO.

"Are you saying a ceedee playing down to,say, 25Hz will also cause excessive excursion?"

No, its a vinyl playback artifact not present in CDs.

"I think that ported speakers may be more susceptible, but that doesn't tell the hole story, IMO."

I would agree.

Man, sometimes vinyl is a real PITA.

Do you know what is the port tuning? My guess it is between 25 and 35 Hz - otherwise you would not have such a problem even with vinyl, which I agree does tend to have some spurious LF due to the mechanical rotation of the disc once every two seconds...