[Phlogiston]

Ron, it might be worth a try, but if the cabinets and woofers were designed with the ports, it is hard to predict the results. But if boomy bass is a problem, stuff something in the ports to see if they sound better. They used to sell a pressure relief port, designed to decrease back pressure without affecting the bass (much).

Found it:

https://www.madisoundspeakerstore.com/fl...-vent-ssv/

One of the most impressive things that can be done to a lot of old speakers is to rebuild the crossover. Pull out the old bi-polar electrolytics and the iron core chokes and replace them with film caps and air core chokes (where it is practical). You might need a new board for the larger parts. I just did this with a set of speakers I built years ago. I used a set of off the shelf Dayton (Parts Express) crossovers, not junk, but no match for the custom pair I just built. It was like taking a paper bag off of your head. I did one speaker at a time so that I could compare before and after. This can cost close to $100 per speaker, which is why the OEM did not do it in the first place.