Originally Posted by davidrmoran
Right, the mass and the behavior of the mass are not exactly the same as the slug of air.
Of course at your knowledge level (beyond mine) you could also have studied the air temperature in the vent, also the effect of cannabis smoke, cat hair, and so on.
All the articles about vent shape (length, smoothness, flare, folds, enclosure loading within enclosures) point out their importance as well. Did you study xmission lines too?
Uh, yeah, doubt it's beyond yours, then or now.
Yes, air temperature, humidity, and density are first-order factors in how sound propagates so were studied and included. Do not recall deriving compensatory factors for cannabis smoke, though smoke in general was touched on at one point IIRC. Smoke was sometimes used to illustrate airflow so we had to know how it changed the sound waves. Cat hair, no, and since I am not a cat fan that was OK with me. I will venture a guess that a hairball in the port will change the tuning frequency, and inserting the full cat more so, as well as introducing other more piercing and less pleasant sounds.
We did study vent (and horn) flares and all that jazz but probably not to the extent it is now. Not that I remember much. Those classes were 30+ years ago. I still have the texts and pull them out now and then to look up something or (more likely) amaze myself with what I once knew and understood. These days I'd use a flow model and computer (COMSOL, Matlab, etc.)
Transmission lines, yes, but I honestly don't remember much. I did review them a few years ago when reading Roger Sanders' woofer TL designs. Since graduation I have dealt with a lot of transmission lines but of the RF/mW variety rather than audio.
Being in Colorado now, I suppose I really should devote more effort to the study of cannabis smoke, but I still need my brain for a few more years...
Wait, what was this thread about?
p.s. Jealous of your RS papers, going through those must be a hoot!