When should I use the included bass port plugs and why? What are the advantages of this? With all Dynaudio speakers with a port, we generally include a foam plug that you can put into port to close the port. Why do we do this? Mainly it’s because when you put a speaker close to the wall you will get more boomy bass. If you have to have the speaker close to the wall, you can close the port which will decreace the amount of bass coming out of the loudspeaker. And that changes the relationship between the speaker and the wall so you can put it closer to the wall. There’s actually another reason to do this. If you have your speaker in a bookshelf where the back of the speaker is enclosed between and behind books and other things on the shelf, I would definitely say “Plug the port”. Try out how that works, because that’s most likely going to sound better than having a port that is halfway sealed. Another interesting reason there might be to plugging the port is if you have a subwoofer – especially if you have an AV receiver and you’re doing a crossover between a subwoofer and a loudspeaker – the phase of a sealed box speaker is more even, the sound roles off more gradually, and you have a very simple phase response, that’s easier to integrate with the subwoofer. The phase relationship between the speaker and the subwoofer really determines how well these two blend together. So very often if you want an easier integration with a subwoofer, start by plugging the port, because with a subwoofer you don't need the bass output from the speaker anyway. So making the sound from the speaker be more smooth will end up in a better result once you integrate everything. How does the port function, and why is it there? That’s a really good question. Basically what the port does is, it adds extra output below the response of the woofer itself. If you imagine the response of the woofer goes lower and lower in frequency, at some point it starts to roll off, it is not able to play those lower frequencies. What you can do is, you can put in an organ pipe essentially. The port has a resonance frequency If you imagine blowing into bottle of water You will have a specific frequency playing The length and the diameter of the port determines that frequency. What we do is, we tune that frequency to be just below where the woofer itself rolls off. Then the port actually helps the woofer gaining som output at frequencies where it is not as efficient. So those two combined will extend the bass into lower frequencies. So that makes the loudspeaker more efficient. You can also put it like this: You're not only getting sound from the front of the woofer, Now we're utilising the sound from the back of the woofer also. And together with the tuning of the port, using that to extend the bass into lower frequencies. You could use it also to extend output, but only in certain frequencies. So generally in hi-fi speakers, you would use it to give a flat response as low down I frequencies as possible. That makes the most efficient speaker but, again, once you place the speaker in a room, or you mix it with a subwoofer you have some different properties you might want to achieve in the loudspeaker which is why it is sometimes beneficial to plug the port.