Blocking Ports on Ported Speakers

Sealed cabinets (acoustic suspension) are known for tight bass, although bass extension is rarely as good as with ported designs (Bass Reflex). But no free lunch here: Ports require careful engineering and making good trade offs. Very easy to have ported designs that produce wooly, bloated, very ill-defined bass.

IN BETWEEN these designs you have the resistive port. This is what the OP is doing with the pillows. You get tighter bass like sealed, but better bass extension like ported. It damps the resonance peak of the woofer due to resistive air load. It’s called an “aperiodic” loading of the woofer.

Dynaudio in the 1980s sold a resistive vent called a “Variovent”. You can Google it.

A previous poster said that the cone doesn’t return before the next signal. That statement is total BS!! Air inside the cabinet always resists the woofer cone from moving out of its center position. When it moves out, it forms a vacuum pulling the woofer cone back to center. When the cone moves into the cabinet, air resists it and wants to push the cone out to its natural center position. BS that the cone can’t or won’t be able to center itself.

As I understand it, as one blocks the port it flattens the roll off of the bass such that the roll off starts at somewhat higher frequency but extends the bass  -10dB point. 

Hello,
I would recommend treating the room and not the speakers. If they are rear ported put some dampers behind the speakers on the wall. Build a frame with 1x4 or 1x6 wood boards. Hone Depot will cut them for you and put mineral wool insulation inside with some cheap fabric over the front. Home Depot sells Viagro burlap in the garden department for $10. When you can swing it get some GIK diffusers and/or bass traps for your room. Treat the room and not the speakers. You will be amazed by the results. YouTube has a bunch of DIY stuff. It works at about 65%-75%. Amazon sells panels for about $30-$40 per 2x2 panel. If you want to know what it will sound like look up near field listening. Pull your speakers out about 4’-6’ from back wall, put about 4’-6’ apart put a chair 5’-6’ in front of speakers. Take a listen. Please let your speakers breathe. Also, get your first reflection points covered too.