If you are placing speakers in a small room, in a cabinet, or near side or back walls, you may be experiencing an effect called boundary reinforcement, which gives you too much mid-bass sound in your speakers.
The solution? Try a port plug! Perfect for both bookshelf and floorstanding speakers, a port plug can help to reduce boundary effects and give you clearer, faster imaging.
If you're using port plugs in a speaker with more than one port, add one plug to each speaker and listen for a few days. If your room or listening preferences are saying that there is still too much mid-bass, try adding another port plug. Experimenting is the key! Port plugs are sold and packaged in pairs.
If you would like more information, read Andrew Welker's post When Should You Use Port Plugs? or watch his video below.
We often get asked about when to use speaker port plugs: should I use them? What do they really do? Why would I want to block a port if you went to the trouble of putting a port in?
All great questions, and it comes to this: you can think of the port as another woofer in the system. So knowing that, it makes sense that when you place the speakers close to a wall, you might affect the sound of the bass.