Sealed vs. Ported Speakers

One thing I noticed when I had a pair of ported speakers was the extreme "woofer pumping" during analog playback. I know this can have a lot to do with cartridge/arm matching and isolation issues, but this wasn't as evident with my sealed box speakers.

It depend on how much you enjoy the sound of the port.

PMC Makes well regarded transmission line speakers that include a bookshelf model, and they aren't so large, and the insanely popular Bose radios are nothing but plastic boxes with a couple of cheap drivers loaded with transmission lines...a concept Bose laughingly claims to have invented. I also had "woofer pumping" issues when I re-introduced my LPs to my system, and that was remedied first with a pair of Nakamichi line filters, and then with the subsonic rolloff switch when I bought a Cambridge 640P...a feature most phono preamps don't seem to have.

...and then there are speakers that can work both ways. Example, Audiokinesis. Mine have port adjustable tuning (you can tilt or shelf the top end as well) and the ability to seal the port if desired.

I think of transmission line speakers are a good idea in the "ported" camp and wonder why there's not more of that sort of thing.

They are a good idea. I think the reason you don't see more of them is that their more complicated internal structure makes them more more expensive to build and heavier to ship than a typical braced and ported tower.